Architectural structures of multi-storey buildings General requirements for multi-storey buildings Multi-storey residential buildings residential buildings from 6 to 9 floors; high-rise buildings from 10 to 25 floors. According to the requirement for the required minimum number of elevators, depending on the number of floors: Buildings of 6 9 floors require 1 elevator; buildings 10 19 floors. 2 elevators; buildings 20 25 floors. In accordance with Federal law Russian Federation dated 2009 No. 384FZ Technical regulations on the safety of buildings and...

Share your work on social networks

If this work does not suit you, at the bottom of the page there is a list of similar works. You can also use the search button

Topic 1. Structural systems of multi-storey buildings. Lecture 1, 2, 3

Literature:

1. A manual for the design of residential buildings. Issue 3. Designs of residential buildings (to SNiP 2.08.01-85).

2. Magai A.A. Architectural design of high-rise buildings and complexes. M., ASV, 2015.

Architectural structures of multi-storey buildings

General requirements for multi-storey buildings

Multi-storey residential buildings residential buildings from 6 to 9 floors; high-rise buildings from 10 to 25 floors.

According to the requirement for the required minimum number of elevators depending on the number of floors:

Buildings of 6 9 floors require 1 elevator;

building 10 19 floors………………. 2 elevators;

building 20 25 floors………………... 3 elevators.

In accordance with the Federal Law of the Russian Federation of 2009 No. 384-FZ “Technical Regulations on the Safety of Buildings and Structures,” buildings and structures are divided into three levels of responsibility:

1) increased level of responsibility - buildings and structures classified as particularly dangerous, technically complex or unique objects;

2) normal level of responsibility - all buildings and structures, with the exception of buildings and structures of increased and reduced levels of responsibility;

3) reduced level of responsibility - buildings and structures for temporary (seasonal) purposes, as well as buildings and structures for auxiliary use related to the construction or reconstruction of a building or structure or located on land plots provided for individual housing construction.

The calculated values ​​of forces in the elements of building structures and the foundation of a building or structure must be determined taking into account the reliability coefficient for responsibility, the accepted value of which should not be lower than:

1) 1.1 - in relation to buildings and structures of a high level of responsibility;

2) 1.0 - in relation to buildings and structures of a normal level of responsibility;

3) 0.8 - in relation to buildings and structures of a reduced level of responsibility.

For buildings and structures of a high level of responsibility, wind and snow loads are recommended to be determined based on the results of blowing the model in a wind tunnel or numerical simulation. Strength calculations of load-bearing structures of buildings and structures of a high level of responsibility should be performed using at least two different software systems to increase the degree of reliability of the calculations.

Types of structural systems of multi-storey buildings.

Basic:

I frame,

II wall,

III barrel (core),

IV shell (pipe).

Combinations:

I+II frame-wall,

I+III frame-barrel,

II+III barrel-wall,

II+IV shell-wall,

III+IV barrel-shell (pipe in pipe).

Basic structural systems

1. Frame KS

In frame structural systems, the main vertical load-bearing structures are frame columns, to which the load from the floors is transferred directly (bezelless frame) or through crossbars (beam frame). The strength, stability and spatial rigidity of frame buildings is ensured by the joint work of floors and vertical structures. Depending on the type of vertical structures used to ensure strength, stability and rigidity, braced, frame and frame-braced frame systems are distinguished.

With a braced frame systema transom-free frame or a transom frame with non-rigid crossbar assemblies with columns is used. With non-rigid nodes, the frame practically does not participate in the perception of horizontal loads (except for the columns adjacent to the vertical stiffening diaphragms), which makes it possible to simplify the design solutions of the frame nodes, use the same type of crossbars along the entire height of the building, and design the columns as elements working primarily in compression. Horizontal loads from the floors are perceived and transmitted to the base by vertical stiffening diaphragms in the form of walls or through braced elements, the belts of which are columns (see Fig. 4). To reduce the required number of vertical stiffening diaphragms, it is recommended to design them with a non-rectangular shape in plan (angular, channel, etc.). For the same purpose, columns located in the plane of vertical stiffening diaphragms can be combined by distribution grillages located at the top of the building, as well as at intermediate levels along the height of the building.

In frame frame systemvertical and horizontal loads are absorbed and transferred to the base by a frame with rigid units of crossbars and columns. Frame frame systems are recommended for low-rise buildings.

In a frame-braced frame systemvertical and horizontal loads are absorbed and transmitted to the base jointly by vertical stiffening diaphragms and a frame frame with rigid units of crossbars with columns. Instead of through vertical stiffening diaphragms, rigid inserts can be used to fill individual cells between the crossbars and columns. Frame-braced frame systems are recommended to be used if it is necessary to reduce the number of stiffening diaphragms required to absorb horizontal loads.

In frame buildings, braced and frame-braced structural systemsAlong with rigidity diaphragms, spatial elements of a closed plan form, called trunks, can be used. Frame buildings with rigid trunks are called frame-trunk buildings.

Frame buildings, the vertical load-bearing structures of which are the frame and load-bearing walls (for example, external, intersectional, staircase walls), are called frame-wall buildings. It is recommended to design buildings of a frame-wall structural system with a frame without transoms or with a transom frame having non-rigid connections between the transoms and the columns.

In shaft structural systems, the vertical load-bearing structures are shafts, formed primarily by the walls of staircase and elevator shafts, on which the floors rest directly or through distribution grillages. Based on the method of supporting the interfloor ceilings, stem systems are distinguished: cantilever, shelf and suspendedsupporting the floors.

1.1. Frame-wall system (with incomplete frame).

External or internal walls in this system are replaced by separate frame racks, which gives flexibility to the planning solution and the ability to create relatively large rooms, inside of which only columns are placed. Rearranging or removing partitions when changing the purpose of premises is relatively easy. The disadvantage of this system is the significant material consumption of the external walls.

1.2. Frame-barrel system.

Flat frame stiffening diaphragms are combined into a spatial support - a trunk that has significantly higher rigidity than individual diaphragms and is therefore capable of withstanding higher horizontal loads. The trunk absorbs all horizontal loads on the building and some vertical ones. The shaft walls are made of either monolithic reinforced concrete or steel. With this system, a hinged connection of frame elements is possible. The trunk, as a rule, is located in the central part of the building and its volume is used to accommodate elevators, stairs and utilities. The space between the central trunk and the outer walls is free of supports. The frame in this system is steel or reinforced concrete.

2. Load-bearing KS with wall load-bearing elements

In these systems, vertical load-bearing structures are designed in the form of walls that absorb all vertical and horizontal loads. The walls are combined into a spatial system using vertical stiffening diaphragms and horizontal floor discs.

There are three main schemes of a system with load-bearing walls: longitudinal-wall; cross-wall; cross-wall.

It is a series of parallel walls oriented along the building, the distance between which is called a span. Accordingly, one-, two- and three-bay buildings are distinguished. All spans can be the same or different sizes. The stability of longitudinal walls in their plane is ensured by placing rigidity diaphragms in a perpendicular direction (individual walls, walls of staircases). The distance between the transverse stiffening diaphragms depends on the thickness of the wall, its material and the vertical distance between horizontal supports (floors) and is regulated by SNiP “Stone and reinforced masonry structures”.

Scheme with longitudinal load-bearing wallsused in buildings up to 17 floors high. The advantage of this scheme is the possibility of changing floor plans during the reconstruction of buildings, as well as the use of local wall materials. The main disadvantage is that the thickness of the walls is determined not only based on strength, but also according to the requirements for thermal protection of premises, which can lead to significant consumption of materials.

Cross-wall schemeused in buildings up to 70 floors high. The distance between the transverse walls is called the pitch. There are narrow (up to 3.6 m) and wide (over 3.6 m) spacing of transverse walls. The thickness of the walls is determined only by strength calculations and may be insignificant. External walls perform only enclosing functions and can be made of lightweight, effective materials. Their thickness is determined primarily by the need for thermal protection of the premises. The longitudinal stability of the building is ensured by stiffening diaphragms (these are, as a rule, staircase walls oriented along the longitudinal axis of the building) and floor discs.

The advantage of this scheme is the use of lightweight enclosing structures, the possibility of installing large openings in them. The main disadvantage is the difficulty in modernizing buildings due to the relatively frequently located transverse main walls.

Cross-wall scheme. It is used in buildings with a cellular planning structure, especially in earthquake-prone areas.

3. CS in the form of cross flat walls,

Bearing all vertical and horizontal loads

Example for points 2 and 3:Structural system with transverse load-bearing walls of the Izmailovo Hotel, Moscow, Russia:

Structural solution: pile field with a monolithic grillage, prefabricated reinforced concrete frame according to the range of standard products with prefabricated stiffening walls. Enclosing structures custom designed. It was envisaged that prefabricated enclosing panels and pylons would be made on white cement in stainless steel formwork.

4. Barrel structural system.

Vertical load-bearing structures are spatial closed-shaped elements in plan - trunks, which absorb all vertical and horizontal loads acting on the building. The ceilings rest directly on the trunks and can be single or multi-trunk.

Depending on the method of supporting the ceilings on the trunk, two main schemes are distinguished:

With console and

Suspended ceilings.

In accordance with this, the buildings of the trunk KS are classified as buildings with cantilever and suspended floors.

In buildings with cantilevered floorsthe outer walls do not reach the level of the foundation, but are supported either by cantilever structures of floors supported on the trunk, or by cantilever belts. The dimensions of the cantilever floors in plan exceed the dimensions of the lower floor, which usually remains open.

In buildings with suspended floorsThe floor structures are supported on one side by the central staircase-elevator shaft, and on the other by vertical hangers (steel or reinforced concrete). The pendants are attached either to the top of the trunk or to the cantilever head.

According to the type of main supports that absorb all vertical and horizontal loads,design diagrams buildings with suspended floors are conventionally divided into the following main groups:

With barrel supports;

With rack supports;

With arched supports;

With combined supports, for example in the form of a trunk and racks.

The design scheme under consideration opens up wide scope for searching for interesting compositional solutions for buildings. Suspensions in buildings of these types can be made of steel strips, rolled profiles, ropes, rods, monolithic prestressed concrete, prefabricated prestressed, steel-reinforced concrete.

4.1. Structural design with a monolithic trunk supporting panel structures on consoles.

4.2. Shell-barrel structural system.

In contrast to the shell system, it is characterized by the fact that in the perception of horizontal and vertical loads, together with the internal trunk, a closed outer shell-box is involved, formed by the structures of the external walls of the building and capable, thanks to appropriate connections, of working under the influence of horizontal loads as one whole.

5. Shell (box-shaped) and suspension systems.

Examples: "Sire Tower":

John Hancock Buildings in Boston

John Hancock Center 100-story skyscraper in Chicago. The main feature of the skyscraper is its hollow structure, reminiscent of a large quadrangular column.

4. Barrel structural systems

Since the 1960s, newly invented structural systems - barrel and shell - have been actively introduced into high-rise construction. Their invention was patented by the American engineer F. Khan in 1961.

The trunk structural system, as the main load-bearing structure of the building, which absorbs loads and impacts, contains a vertical spatial rod a stiffening trunk (closed or open section) for the entire height of the building. Since the trunk is most often located at the geometric center of the plan, the common term “stiffness core” has arisen. Stiffening trunks are the most specific internal vertical load-bearing structure for high-rise construction. The floors rest directly on the trunks; buildings can be single- or multi-trunk. The most common design option is a centrally located monolithic reinforced concrete shaft. Depending on the load (number of floors), the thickness of the trunk walls in the lower tier can reach 60-80 cm, and in the upper tier it can be reduced to 20x30 cm.

In terms of design and planning, the relatively rarely adopted design of an open profile shaft, for example, a cruciform section, is successful. It eliminates the labor-intensive and metal-intensive installation of numerous overhead lintels required in closed-section shafts, and simplifies the installation of elevators. Limitations in their use are justified only in particularly tall structures, when the rigidity of an open-section trunk may be insufficient.

The steel structures of the shafts are in most cases a lattice system, concreted after installation. Exceptions to this rule are extremely rare, when the trunk has not only load-bearing, but also architectural and compositional functions.

Stiffening trunks are the most specific internal vertical load-bearing structure for high-rise construction. It is inherent in most high-rise buildings of various structural systems: stem, stem-wall, frame-stem and shell-stem.

The barrel structural system is characterized by the fact that all horizontal and vertical loads are absorbed by the shaft structures, consisting of monolithic walls or individual diaphragms combined into a spatial element. It is used in cases where it is necessary to increase the shock-absorbing capacity of a structure against seismic shocks. In shaft structural systems, the vertical load-bearing structures are shafts, formed primarily by the walls of staircase and elevator shafts, on which the floors rest directly or through distribution grillages.

Trunk systems have their own varieties: cantilever support of the floors on the trunk, suspension of the outer part of the ceiling to the upper load-bearing console “hanging house” or its support by means of walls on the lower load-bearing console, intermediate arrangement of load-bearing consoles one floor high with the transfer of load from part of the floors to them.

The trunk or core in high-rise buildings is a rigid (monolithic) staircase-elevator assembly. In the first case, the ceilings are rigidly clamped in the walls of the trunk, in the second they are freely supported by the trunk and, in addition, are held in place by pendants fixed in the upper or intermediate part of the trunk. In buildings with cantilever floors (floors), the outer walls do not reach the level of the foundation, but are supported either by cantilever structures of floors supported on the trunk, or by cantilever belts. The floors are supported on one side by the central staircase-elevator shaft, and on the other by vertical hangers (steel or reinforced concrete). Suspensions in buildings of these types can be made of steel strips, rolled profiles, ropes, rods, monolithic prestressed concrete, prefabricated prestressed, steel-reinforced concrete. The pendants are attached either to the top of the trunk or to the cantilever head. The dimensions of the cantilever floors in plan exceed the dimensions of the lower floor, which, as a rule, remains open.

Based on the type of main supports that absorb all vertical and horizontal loads, the structural designs of buildings with suspended floors are conventionally divided into three main groups: with shaft supports; with rack supports; with arched supports. A special group is represented by buildings with combined supports, for example in the form of a trunk and racks.

This design scheme opens up wide opportunities for finding interesting architectural, planning and compositional solutions for buildings.

Another system used in the construction of high-rise buildings is the suspension system, which is usually built from the bottom up, when the floors can be suspended from the stiffening core and trusses (coverings). Since each floor is first installed on the ground and then raised, interior work can continue on the upper floors while the new tier is installed at ground level. The process can also go in the opposite direction in suspended structures, i.e., after the installation of stiffening cores and trusses is completed, the floors are mounted from top to bottom and internal work proceeds in the same sequence. There are several possible advantages due to this reverse arrangement: protective scaffolding along the entire height of the building is no longer needed, but is used only for one floor, while the individual working levels are protected by the floor above. It takes less effort to set up a winter construction site, the ground floor remains open and can be used for construction fixtures, which is especially convenient in the city center. Suspended structures are not subject to the risk of longitudinal bending this allows the use of flexible ties. This advantage can be quickly lost if fire retardant cladding is required (for example, in the case of the Bank of Hong Kong and Shanghai, (Foster and Partners architects). The length of the connecting ties is subject to changes as a result of differences in winter and summer temperatures, and these changes are exacerbated with each additional floor. The requirements of suspended systems for the facade are very loose. The ties can be carried inside to prevent their expansion due to temperature differences, or they can be installed outside with appropriate protection. In both cases, changes in length must be absorbed by the expansion joint.

One of the tallest buildings with suspended floors is the 31-story Standard Bank Center building in South Africa with four underground tiers. The dimensions of the building in plan are 33.1x33.1 m, height -130 m. The main supporting structure is a 4-section trunk measuring 14.2x14.2 m with monolithic reinforced concrete walls. At the levels of the 11th, 21st and 31st floors, reinforced concrete prestressed cantilever belts with an overhang of 10.45 m rest on the trunk. Two prestressed reinforced concrete hangers are attached to the ends of the consoles on each side of the building, which support the structure of the nine underlying floors. The floor structures are designed in the form of ribbed reinforced concrete slabs, one side resting on the walls of the central trunk, and the other on contour reinforced concrete beams attached to pendants. The span of contour beams is 14.2 m, the radius is 5 m.

An example of the use of a suspended system is the building of the BMW Tower company (Munich, Germany), in which the volumetric-spatial solution represents a four-lobe plan, which made it possible to make maximum use of the light front of the entire building and give it a plastic, expressive form, and a technical recessed on the facade the floor divides the volume into two unequal parts, interrupting the monotony of the facade (Fig. 3.4.6). Since the tower is a building with suspended floors, its construction was carried out in a special way. All 22 floors were built on the ground and then raised. Four powerful trunks with additional columns support suspended floors. The height of the building is 101 meters and the diameter is 52 meters.

The scheme with cantilever floors was used in the construction of the 37-story Tour du Midi administrative building with a height of 149.2 m in Brussels (Fig. 3.4.7). The dimensions of the building are 38.6 x 38.6 m. The building is supported by a central staircase and elevator shaft measuring 19.7 x 19.7 m with a steel concrete frame. The load-bearing elements of the floors are cantilever prefabricated monolithic reinforced concrete beams the length of the entire building, embedded in the walls of the trunk. Console reach 9.65 m.

The barrel systems under consideration are not a common design solution. The most common are systems with combined solutions: a trunk in combination with either a frame frame, or a load-bearing frame of external walls, or with load-bearing walls and diaphragms.

In terms of design and planning, the relatively rarely adopted design of an open profile shaft, for example, a cruciform section, is successful. It eliminates the labor-intensive and metal-intensive installation of numerous overhead lintels required in closed-section shafts, and simplifies the installation of elevators. Limitations in their use are justified only in particularly tall structures, when the rigidity of an open-section trunk may be insufficient. The steel structures of the shafts are in most cases a lattice system, concreted after installation. Exceptions to this rule are extremely rare, when the trunk has not only load-bearing, but also architectural and compositional functions.

An example of a high-rise building of a frame-stem structural system is the 57-story administrative building "Maine Montparnasse" in Paris (France) with a height of 200 m. The building has a biconvex shape in plan with a steel frame and a monolithic trunk with plan dimensions of 37x16 m and a stepped shape in height. External steel columns of I-beam profile are located at intervals of 5.7 m; walls made of curtain panels. Another example is the 39-story building of the Stadt Berlin Hotel in Berlin, Germany. The building is rectangular in plan, measuring 50x24 m; made with reinforced concrete external columns located at intervals of 3.0 m and internal walls of a multi-cell shaft of staircase and elevator shafts with a total size of 48x9.3 m. thickness from 70 cm to 30 cm. One of additional ways increasing the rigidity of buildings of a frame-trunk structural system is the installation of horizontal belts - trusses connecting the frame with the trunk of rigidity at several levels along the height of the building, which makes it possible to design buildings with a height of 250 meters or more. The horizontal belts are rigidly connected to the shaft structures and hinged to the outer columns. When the trunk bends, the belts act as struts that transfer axial stresses directly to the columns along the perimeter of the building. These columns, in turn, act as rods that prevent the trunk from bending. Thus, the trunk completely absorbs horizontal shear forces, and the horizontal belts transfer the vertical shear load from the trunk to the frame structures of the external walls. In this case, the building works as a single whole according to a scheme similar to that of a box-section cantilever rod. An example of a suspended system is the 114-meter-high “Hypo-House” building in Munich, the third tallest skyscraper in the city. In terms of design, this building is similar to the BMW building, the same four cylinders, but they support the floors along the outer contour. The building was reconstructed in 2006. Further reconstruction of the building will involve its transfer to the “Green Building”, a green building, which will require significant changes in part during further reconstruction engineering systems and equipment, as the building currently has central air conditioning.

5. Structural diagram with a monolithic trunk supporting panel structures on consoles.

6. Shell (box-shaped) and suspension systems.

Shell (box-shaped) systems

Since the 1960s, newly invented structural systems - box-shaped (shell) and barrel - have been actively introduced into high-rise construction. Their invention was patented by the American engineer F. Khan in 1961.

The box structural system is the most rigid structural system, since its load-bearing structures are located along the outer contour. Therefore, it is most often used in the design of the tallest buildings 200 m and above.

The main box system is accompanied by two combination optionsshell-barrel (“pipe in pipe”) And shell-diaphragm (“tube bundle”).

In a box systemin the center of the plan there is a shaft with elevator shafts and common halls located in its space. The trunk absorbs the bulk of all loads, and load-bearing elements located along the perimeter of the building in the form of individual racks (columns), lattice systems (trusses, composite rods, etc.), pylons, which can also be combined into a single structure. The rigidity of the barrel system, its stability and ability to dampen forced vibrations are ensured by embedding the central barrel into the foundation.

An individual specific task in the design of shell buildings was the solution of the design of a load-bearing outer shell, combining load-bearing and enclosing functions.

A means of increasing the rigidity of the shell can also be the transition from shell toshell-diaphragm structure (“tube bundle”).The shell structure is made of both steel elements and reinforced concrete. Reinforced concrete shells are made monolithic or prefabricated, but most often from structural lightweight concrete, combining the load-bearing and heat-insulating functions of the wall. In recent years, shells in Europe have been made predominantly monolithic from heavy concrete (perforated wall), followed by insulation and external cladding.

For elements of steel shells, rolled or welded elements of a closed rectangular section are most often used, also with subsequent insulation and cladding.

To increase the resistance to external influences of the supporting system of buildings with a height of more than 250 m, mainly barrel structural systems are used: “pipe in pipe” and “pipe in truss”. Most high-rise buildings of the shell type are built on a shell-stem system, although some outstanding buildings, such as the 100-story John Hancock building in Chicago and the International Financial Center in Taipei, have a “tube-in-truss” shell structural system (Fig. 3.3. 1). According to this scheme, the outer perimeter of the walls is rigidly connected to the trunk and additionally reinforced with powerful diagonal braces. In this case, the entire building acts as a rigid cantilever embedded in the body of the foundation.

Shell (box-shaped) CS is based on the principle of accepting all horizontal loads only by the outer wall box, which is usually solved in the form of a rigid spatial lattice (non-braced or braced).

In essence, the lattice is frame elements placed on the perimeter of the building. The frame posts serve as partitions, the frame crossbars serve as lintels above the window. Internal supports (most often a centrally located trunk) work only for vertical loads. Within the central trunk there are elevators, staircases, and all main utilities. With such a system, it is possible to design wide buildings and deep workspaces with artificial lighting and microclimate.

Since the bulk of the load-bearing structures are located along the contour of the building, this increases the building’s resistance to horizontal loads and gives the shell system an advantage over other systems, especially in the construction of high-rise buildings. In addition, it is possible to lighten the design of the floors, since they are freed from transmitting horizontal loads to the trunk.

The shell (box-shaped) structural system is based on the principle of the perception of all horizontal loads only by the outer wall box, which is usually solved in the form of a rigid spatial lattice (unbraced or braced).

Examples: "Sire Tower":

Chicago is called the "Windy City" with an average wind speed of 16 miles per hour. To ensure the skyscraper's stability, architect Bruce Graham used a structure of square-section bonded steel tubes to form the building's rigid frame.

The lower part of the Cire Tower up to the 50th floor consists of nine pipes combined into a single structure and forming a square at the base of the building, spread over two city blocks.

Above the 50th floor the frame begins to narrow. Seven pipes go to the 66th floor, five more to the 90th floor, and two pipes form the remaining 20 floors. The amount of steel used to build this tubular frame would be enough to build 52,000 cars. It is very violent: the top of the structure swings with a maximum amplitude of only 1 foot (0.3 m).

The total mass of the building is 222,500 tons. It stands on 114 concrete and stone piles driven deep into a solid rock base. The lowest level of the tower lies 13 m below street level. More than 600,000 cubic meters of concrete were used to pour the foundation—enough to build a five-mile, eight-lane highway. The building contains 3,220 km of electrical cable. And telephone cables (their length is 69,200 km) can wrap our entire planet around the equator 1.75 times.

Frame-barrel system Petronas Tower, Kuala Lumpur, Malaysia:

The twin towers of the Petronas Tower shopping and business center are 452 m high each. The foundation supports of the towers are located underground at a depth of over 100 m, the total area of ​​the complex is about 1 million m2.

The glass, concrete and steel structure was designed by Ranhill Bersekutu and Thornton Tomasetti. During the study of the area, it turned out that there is different soil under the towers, which would cause subsidence of one of the towers. Therefore, it was decided to move them 60 meters and drive piles 100 meters, making it the largest foundation in the world. The plan of the building has the symbol of Islam - an octagonal star. This was facilitated by the participation of the Prime Minister of Malaysia, who wanted to build a building in the style of Islam. Both buildings are connected by an air bridge at the 42nd floor level. The bridge provides not only fire safety, but also affects the overall reliability of the building, which was already designed to high level. A huge amount of steel went into the construction of the Petronas Tower - 36,910 tons. Due to the use of materials only from Malaysia, it was necessary to try to replace the steel with new elastic concrete, which was successfully produced here for the new high-rise. The building has underground parking for 4,500 cars. The building is equipped with high-speed elevators, so it takes only 90 seconds to get to the top floor. For the elevator, due to limited space, an interesting scheme was used: the elevators themselves are two-story, respectively, one of them stops only on even floors, and the other on odd ones.

6.1. Box-barrel (shell-barrel) structural system (or “pipe-in-pipe”)

Box-trunk (shell-trunk) structural system (or “pipe in pipe”) is characterized by the fact that horizontal and vertical loads in the building are perceived jointly by the internal trunk and a closed outer box (shell) formed by the load-bearing structures of the external walls. The outer frame is usually made in the form of a rigid spatial unbraced lattice, the elements of which are steel or reinforced concrete columns, installed, as a rule, with small steps, and floor-by-floor strapping beams. Lattice elements, along with load-bearing elements, also perform enclosing functions. With a large column spacing, the lattice is reinforced with braces or braced belts, arranged in two or more tiers along the height of the building. Sometimes the outer box is formed by monolithic reinforced concrete walls with openings.

The joint operation of the outer shell and the inner shaft is ensured by vertical connections (grillages) within the technical floors, as well as by rigid disks of the floors. Due to the joint work of the outer shell and the barrel when using the shell-barrel system, the rigidity of the entire structure increases by 30×50% compared to the frame-barrel structural system and, accordingly, deflections from horizontal loads are reduced.

This system is called "Tube-A-Tube" ("pipe in a pipe"). The outer shell is usually made in the form of a rigid spatial unbraced lattice, the elements of which are steel or reinforced concrete columns and floor-to-floor strapping beams. Columns are usually installed in small increments. When the column spacing is large, the lattice is reinforced with braces or braced belts, placed in two or more tiers along the height of the building. Sometimes the outer shell is formed by monolithic reinforced concrete walls with openings.

Examples:

Stem-frame system of a BMW building, Munich, Germany

Construction of the building took place from 1968 to 1972 and was completed in time for the start of the Olympic Games held in the city. The architect was the Austrian Karl Schwanzer. The 22-story skyscraper, 101 meters high, was opened on May 18, 1973. Externally, the building is created to resemble a four-cylinder engine, and the museum located nearby depicts a cylinder head. All four “cylinders” do not stand on the ground, but on an inconspicuous central base. The diameter of the building is 52.3 meters. Construction cost 109 million marks. As of 2013, approximately 1,500 employees work in the building.

Data

It was originally planned to place a huge corporate logo on the supporting crosspiece at the top of the tower, but the Munich architectural department considered this too catchy. The company began a lawsuit, and during it, at the beginning of the Olympics, it hung its emblems, printed on canvas, so that they could be seen from the Olympic stadium. For this, BMW was fined 110 thousand marks. Only in the fall of 1973 the concern received permission to display its logos on all four sides

7. Large-panel buildings

For short-span slabs, it is recommended to use a cross-wall structural system. It is recommended to determine the dimensions of structural cells based on the condition that the floor slabs rest on the walls along the contour or on three sides (two long and one short).

For mid-span floors, cross-wall, transverse-wall or longitudinal-wall structural systems can be used.

With a cross-wall structural system, it is recommended to design the external walls as load-bearing, and design the dimensions of the structural cells so that each of them is covered by one or two floor slabs.

With a cross-wall structural system, the external longitudinal walls are designed as non-load-bearing. In buildings of such a system, it is recommended to design the load-bearing transverse walls through the entire width of the building, and to place the internal longitudinal walls so that they unite the transverse walls at least in pairs.

With a longitudinal-wall structural system, all external walls are designed as load-bearing. The pitch of the transverse walls, which are transverse stiffening diaphragms, must be justified by calculation and taken no more than 24 m.

In large-panel buildings, in order to absorb forces acting in the plane of horizontal stiffening diaphragms, prefabricated reinforced concrete floor and roof slabs are recommended to be connected to each other by at least two connections along each face. The distance between the links is recommended to be no more than 3.6 m. The required cross-section of the links is determined by calculation. It is recommended to take the cross-section of the connections in such a way (Fig. 6) that they ensure the perception of tensile forces of at least the following values:

for connections located in floors along the length of a building extended in plan - 15 kN (1.5 tf) per 1 m of building width;

for connections located in floors perpendicular to the length of a building extended in plan, as well as connections for compact buildings - 10 kN (1 tf) per 1 m of building length.

Monolithic construction

How it all began. Story monolithic construction

Ancient Rome. The history of the development of monolithic construction is interesting. The first and most famous example of a structure using this method dates back to 118-120. AD In Rome, a wonderful monument from the era of Emperor Hadrian has been preserved - the temple of all gods - the Pantheon (architect Apollodorus).

Russia. At the beginning of the 20th century, in connection with the search for new forms, new possibilities for concrete were discovered, and the traditional aesthetics of architectural composition was replaced by a different aesthetics of constructivism.

New technologies also appeared in Russia, and appeared back in the 19th century, thanks to the construction of temples and palaces. In 1802, reinforced monolithic concrete was used to construct the floors of the palace in Tsarskoe Selo (now the city of Pushkin). In the 80s of the 19th century, a number of buildings were built in St. Petersburg, including the State Bank building (70-72 Fontanka River embankment), the walls and ceilings of which were made of monolithic reinforced concrete.

Since the late 20s, various monolithic structures have been introduced into construction practice: shells, domes, tents, etc. Thus, in Moscow the Central Telegraph was built (Tverskaya St., 7 (1927-1929)), the Izvestia house on Pushkinskaya Square (1927-1929), and the buildings of the Ministries of Light Industry and Agriculture (Sadovo-Spasskaya St. , d.11/1); in Leningrad - House of Soviets (Moskovsky Prospekt, 212). The versatility of monolithic construction made it possible to change familiar forms, creating a new architectural appearance of the country.

In 1947, it was decided to build skyscrapers that were in no way inferior to American models, and ideally superior to them (a task almost similar to that set by Emperor Hadrian during the construction of the Pantheon).

Before the start of construction of high-rise buildings in Moscow, there was no practice of constructing structures higher than 10 floors. We had to build and design in parallel. It was also necessary to take into account the complex geology of Moscow soils. Therefore, despite all the similarities between our high-rise buildings and American skyscrapers, they are significantly lower than their prototypes.

All “Seven Sisters” were founded on one day, September 7, 1947 - the day of Moscow’s 800th anniversary: ​​the Moscow State University building on Vorobyovy Gory (310 m), resembles the facade of a government building in Manhattan (Manhattan Municipal Building); hotel "Ukraine" (200 m); residential building on Kudrinskaya Square (156 m, reminiscent of the Cleveland skyscraper Terminal Tower); residential building on Kotelnicheskaya embankment (176 m); administrative and residential building on Red Gate Square (138 m); the building of the Ministry of Foreign Affairs (172 m, similar to the Woolworth Building in Manhattan) and the Leningradskaya Hotel (136 m, similar to the Manhattan United States Courthouse).

Prospects. In monolithic housing construction, two directions of development can be traced. One of them is associated with the massive construction of ordinary buildings (mainly residential), the other is aimed at the construction of unique structures. The first direction covers a huge housing market of all categories. The demand for quality housing is growing, and at the same time the need for a variety of architectural solutions that create a modern look for “dormitory” areas is growing. There can be no doubt: there will be enough work in this area for 100 years.

The second direction is the construction of entire complexes based on individual projects, acting as urban planning accents (an example is the Moscow City office center). (Marina Alazneli, SVEZA press service)

Prefabricated reinforced concrete buildings

A panel is a planar prefabricated element used for the construction of walls and partitions. A panel with a height of one floor and a length in plan not less than the size of the room that it encloses or divides is called a large panel; panels of other sizes are called small panels.

A prefabricated slab is a factory-made planar element used in the construction of floors, roofs and foundations.

A block is a self-stable prefabricated element of predominantly prismatic shape during installation, used for the construction of external and internal walls, foundations, ventilation devices and garbage chutes, and placement of electrical or sanitary equipment. Small blocks are usually installed manually; large blocks - using mounting mechanisms. Blocks can be solid or hollow.

Large blocks of concrete buildings are made of heavy, light or cellular concrete. For buildings one to two floors high with an expected service life of no more than 25 years, gypsum concrete blocks can be used.

A volumetric block is a prefabricated part of the building volume, fenced on all or some sides.

Volumetric blocks can be designed as load-bearing, self-supporting or non-load-bearing.

A load-bearing block is a volumetric block on which the volumetric blocks located above it, floor slabs or other load-bearing structures of the building rest.

Self-supporting is a volumetric block in which the floor slab rests floor-by-floor on load-bearing walls or other vertical load-bearing structures of the building (frame, staircase-elevator shaft) and participates with them in ensuring the strength, rigidity and stability of the building.

A non-load-bearing block is a volumetric block that is installed on the floor, transfers loads to it and does not participate in ensuring the strength, rigidity and stability of the building (for example, a sanitary cabin installed on the floor).

Prefabricated buildings with walls made of large panels and floors made of prefabricated slabs are called large-panel buildings. Along with planar prefabricated elements, non-load-bearing and self-supporting volumetric blocks can be used in a large-panel building.

A prefabricated building with walls made of large blocks is called large-block.

A prefabricated building made of load-bearing volumetric blocks and planar prefabricated elements is called panel-block.

A prefabricated building made entirely of volumetric blocks is called volumetric block.

Unification and industrialization of solutions in multi-storey civil construction

To date, the All-Union Construction Catalog of standard structures and products from various materials for buildings and structures of all types of construction has been created.

On the basis and in development of the All-Union, sectoral and territorial catalogs for housing and civil construction have been created, focused on existing local production and raw material bases. In total, over 130 catalogs are currently used in housing and civil construction. The country has a powerful construction industry. Such a huge production base required the development of a new system - an open typing system. Its meaning is that the object of typification is not buildings or their parts, but a strictly verified limited assortment of industrial products, from a set of which in various combinations must be completed buildings, varied in space-planning solutions and facade architecture.

This fundamentally new typification system is largely implemented in the method of the Unified Catalog of Unified Products for Construction in Moscow (territorial catalog TK1-2). It includes: panel structures for the construction of residential buildings; frame-panel structures (with a prefabricated reinforced concrete unified frame) for the construction of civil and industrial buildings.

The main provisions of the Unified Catalog: all sizes are subject to the rules of modular coordination (MCRC); the rules for linking all prefabricated products to the coordinate axes of buildings are regulated; combinatorics of characteristic architectural and structural situations have been identified; the most progressive and economical types of structures were selected; unified interface units for structural elements have been developed; standard loads and a number of other parameters (thermophysical, etc.) have been unified; the series of geometric dimensions of spans, steps, and heights were unified.

The geometric parameters adopted as the basis of the Unified Catalog are subject to certain patterns based on mathematical modular series; the 0.6 m module is adopted as the main one and, if necessary, additional module 0.3 m. The catalog is based on this modular series. It contains the necessary nomenclature for construction residential buildings with a floor height of 2.8 m and a single modular range of dimensions in plan 1.2; 1.8; 2.4; ...; 6.6 m (M = 0.6 m), public buildings with a floor height of 3; 3.3; 3.6; 4.2; 4.8; 6.0 m, based on a single modular range of dimensions in plan 1.8; 2.4; 3; 3.6; 4.8; 6; 7.2; 9; 12; 15; 18; 24 m.

When compiling the catalog, it is provided for the implementation of various structural systems of buildings: panel with narrow, wide and mixed spacing of transverse load-bearing walls for residential buildings; frame crossbars with transverse and longitudinal directions for residential and public buildings, etc. The number of storeys for residential buildings is 9, 12, 16, 25 floors, public - up to 30 floors.

The catalog includes a wide range of products that ensure the creation of a variety of architectural, planning and volumetric structures of buildings (houses with a rectangular configuration, corner, stepped, with a shift in plan, trefoil, etc.).

The most rational economic and at the same time promising designs and structural schemes of industrial panel and frame residential buildings, public and industrial buildings have been selected for the Catalog.

The idea of ​​the Unified catalog “from product to project” also allows for such standard design methods as block-sectional, block-apartment, etc. In enlarged space-planning elements (KOPE), products and methods of the Unified Catalog are used (see below).

It is recommended to design monolithic and prefabricated monolithic residential buildings on the basis of wall structural systems. During the feasibility study, the use of barrel and frame-barrel structural systems is allowed.

For monolithic and precast-monolithic buildings with monolithic or prefabricated-monolithic external walls, it is recommended to use a cross-wall structural system with load-bearing transverse and longitudinal walls, including external ones. Monolithic and prefabricated monolithic floors are considered as clamped along the contour.

Prefabricated floors are considered to be restrained by walls and supported on two or three sides.

For prefabricated monolithic buildings with prefabricated external walls in the presence of through internal longitudinal walls, it is recommended to adopt a cross-wall system with non-load-bearing external walls. In the presence of separate longitudinal stiffening diaphragms, a transverse-wall structural system is used, in which the floors are considered as sandwiched by walls on two opposite sides.

For prefabricated monolithic buildings, with monolithic floors clamped on both sides, it is allowed to use a cross-wall structural system with a flat frame or radial arrangement of walls.

Depending on the purpose and size of the premises located on the first floors of monolithic and prefabricated monolithic buildings, wall or frame structural systems can be used:

wall systems with complete coincidence of the axes of the lower and upper floors;

wall systems with incomplete (partial) coincidence of the axes of the walls of the lower and upper floors;

frame systems with complete coincidence of the frame axes of the lower and upper floor walls;

frame systems with incomplete (partial) coincidence of the axes of the frame of the lower and walls of the upper floors.

Wall systems with complete coincidence of the axes of the walls of the lower and upper floors should be used if enterprises that do not require large premises are located in the lower floors of residential buildings.

Wall systems with incomplete (partial) coincidence of the axes of the walls of the lower and upper floors are advisable to use if the lower floors contain large rooms (span 9 m or more) and the presence of supports in the form of pylons, columns of complex profiles, arches, walls, staircases is allowed. elevator nodes.

Based on the method of their construction, it is recommended to use the following types of monolithic and prefabricated monolithic buildings:

with monolithic external and internal walls erected in sliding formwork (Fig. 2, a) and monolithic floors erected in small-panel formwork using the “bottom-up” method (Fig. 2, b), or in large-panel floor formwork using the “top-down” method ( Fig. 2, c);

with monolithic internal and end external walls, monolithic floors erected in volumetric-adjustable formwork, removed to the facade (Fig. 2, d), or in large-panel formwork for walls and ceilings (Fig. 2, e). In this case, the external walls are made monolithic in large-panel and small-panel formwork after the construction of internal walls and ceilings (Fig. 2, e) or from prefabricated panels, large and small blocks of brickwork;

with monolithic or prefabricated-monolithic external walls and monolithic internal walls, erected in adjustable formworks removed upward (large-panel or large-panel in combination with block) (Fig. 2, g, h). In this case, the floors are made prefabricated or prefabricated monolithic using prefabricated shell slabs, which act as permanent formwork;

with monolithic external and internal walls, erected in volumetric movable formwork (Fig. 2, i) using tiered concreting method, and prefabricated or monolithic floors;

with monolithic internal walls erected in large panel wall formwork. In this case, the floors are made of prefabricated or prefabricated monolithic slabs, the outer walls are made of prefabricated panels, large and small blocks, and brickwork;

with monolithic stiffening cores erected in adjustable or sliding formwork, prefabricated wall and ceiling panels;

Sliding formworkcalled formwork, consisting of panels mounted on jacking frames, a working floor, jacks, pumping stations and other elements, and intended for the construction of vertical walls of buildings. As the walls are being concreted, the entire system of sliding formwork elements is lifted upward by jacks at a constant speed.

Small panel formworkcalled formwork, consisting of sets of panels with an area of ​​​​about 1 m2 and other small elements weighing no more than 50 kg. It is allowed to assemble panels into enlarged elements, panels or spatial blocks with a minimum number of additional elements.

Large panel formworkcalled formwork, consisting of large-sized panels, connection and fastening elements. The formwork panels accept all technological loads without installing additional load-bearing and supporting elements and are equipped with scaffolding, struts, adjustment and installation systems.

Volume-movable formworkcalled formwork, which is a system of vertical and horizontal panels, hingedly combined into a U-shaped section, which in turn is formed by connecting two L-shaped half-sections and, if necessary, inserting a floor panel.

Volumetric-movable formwork is called formwork, which is a system of external panels and a folding core that moves vertically in tiers along four racks.

Block formwork is a formwork consisting of a system of vertical panels and corner elements, hingedly combined by special elements into spatial block forms.

Masonry buildings may have masonry walls or precast walls (blocks or panels).

Masonry is made of brick, hollow ceramic and concrete stones (from natural or artificial materials), as well as lightweight brickwork with slab insulation, backfill made of porous aggregates or polymer compositions foamed in the cavity of the masonry.

Large blocks of stone buildings are made of brick, ceramic blocks and natural stone (sawn or clean hew).

The panels of stone buildings are made of vibrobrick masonry or ceramic blocks. External wall panels may have a layer of slab insulation.

Structural system	Distance between temperature-shrinkage joints, m, for floors
		monolithic	prefabricated
Cross-wall with load-bearing external and internal walls, longitudinal wall
Cross-wall with non-load-bearing external walls, cross-wall with separate longitudinal diaphragms
Cross-wall without longitudinal diaphragms

Monolithic concrete walls

External and internal walls made of monolithic concrete when using adjustable formwork are erected simultaneously or sequentially (first the internal walls, and then the external ones, or vice versa).

For the construction of load-bearing walls made of monolithic concrete, it is recommended to use heavy concrete of a class not lower than B7.5 and light concrete of a class not lower than B5. In buildings with a height of four or less floors, it is allowed to use lightweight concrete of class B3.5 in load-bearing walls. For internal walls, the density of lightweight concrete should be at least 1700 kg/m3.

It is recommended to design monolithic single-layer external walls from lightweight concrete with a dense structure. If the intergranular porosity of concrete is no more than 3% and the concrete class is not lower than B3.5 in normal and dry humidity zones, it is allowed to design external walls without a protective and decorative layer. External lightweight concrete walls without a protective and decorative layer should be painted with hydrophobic compounds.

It is recommended to design external single-layer walls from lightweight concrete with a density of no more than 1400 kg/m3. During a feasibility study, it is allowed to use lightweight concrete with a density of more than 1400 kg/m3 in single-layer external walls.

Layered exterior walls can be designed with two or three main layers. Double-layer external walls can have an insulating layer on the outside or inside. In three-layer external walls, the insulating layer is located between the concrete layers.

Two-layer external walls with insulation on the outside can be monolithic or prefabricated monolithic.

Monolithic walls are erected in two stages. At the first stage, the inner layer of the wall is erected in adjustable formwork from heavy concrete, at the second - the outer layer of heat-insulating lightweight monolithic concrete.

A prefabricated monolithic wall consists of an internal monolithic layer made of heavy concrete, and an outer layer of prefabricated elements.

A two-layer external wall with insulation on the inside consists of an external monolithic concrete layer, an internal insulating layer - from aerated concrete blocks no more than 5 cm thick or from rigid slab insulation (for example, polystyrene foam) no more than 3 cm thick and an internal finishing layer (Fig. 26, a).

Limiting the thickness of insulating layers is associated with ensuring normal heat and humidity conditions for the walls.

It is advisable to use heavy concrete at design winter temperatures not exceeding minus 7°C. In other cases, it is necessary to use lightweight concrete.

First, a layer of insulation is laid on the inner formwork panel, then the formwork is assembled and a layer of monolithic concrete is concreted. In this case, it is possible to use insulation boards that are not calibrated in thickness;

Insulation boards are installed after concreting the walls.

In this case, it is necessary to use insulation boards calibrated in thickness.

When designing double-layer walls with insulation on the inside, it should be taken into account that the construction of such walls is simpler than walls with insulation on the outside, but their use is limited by the condition that there is no dew point within the thickness of the insulating layer.

It is recommended to design three-layer external walls as prefabricated monolithic ones, consisting of an internal load-bearing layer of monolithic heavy concrete and an insulated prefabricated shell panel installed on the outside. The shell panel can be installed before and after the construction of the monolithic part of the wall (Fig. 26, b).

It is allowed to design three-layer external walls with external and internal layers of monolithic concrete and an insulating layer of rigid slab insulation (Fig. 26, c).

Monolithic buildings definition according to SNiP 2.08.01.-85

Monolithic and prefabricated monolithic buildingsAccording to the method of their construction, it is recommended to use the following types:

with monolithic external and internal walls erectedin sliding formworkand monolithic floors erectedin small-panel formwork using the “bottom-up” method, or in large-panel formwork for floors using the “top-down” method;

with monolithic internal and end external walls, monolithic ceilings,erected in volumetric-adjustable formwork, extracted onto the façade, orin large-panel formwork for walls and ceilings. External walls in this case are made monolithicin large-panel and small-panel formworkafter the construction of internal walls and ceilings or from prefabricated panels, large and small blocks of brickwork;

with monolithic or prefabricated monolithic external walls and monolithic internal walls, erected in adjustable formwork, removed upwards (large-panel or large-panel in combination with block). In this case, the floors are made prefabricated or prefabricated monolithic using prefabricated slabs - shells, which act as permanent formwork;

with monolithic external and internal walls erected in volumetricmobile formwork using tiered concreting method, and prefabricated or monolithic floors;

with monolithic internal walls erectedin large panel formwork walls . In this case, the floors are made of prefabricated or prefabricated monolithic slabs, the outer walls are made of prefabricated panels, large and small blocks, and brickwork;

with monolithic stiffening cores, erected in adjustable or sliding formwork, prefabricated wall and ceiling panels;

with monolithic stiffening cores, prefabricated frame columns, prefabricated external wall panels and slabs erected using the lifting method.

Monolithic buildings

The load-bearing CS of a monolithic reinforced concrete building consists of a foundation, vertical load-bearing elements (columns and walls) resting on it and combining them into a single spatial system of horizontal elements (floor slabs and coverings).

Depending on the type of vertical load-bearing elements (columns and walls), structural systems are divided into (Fig. 5.1, a, b, c):

Columnar, where the main load-bearing vertical element is columns;

Wall, where the main load-bearing element is the wall;

Column-wall, or mixed, where the vertical load-bearing elements are columns and walls.

Fragments of building plans:

a - columnar KS; b - wall CS; c - mixed CS;

1 - floor slab; 2 - columns; 3 walls

The lower floors are often designed in one structural system, and the upper floors in another. The structural system of such buildings is combined.

Depending on engineering-geological conditions, loads and design specifications, foundations are made in the form of separate slabs of variable thickness for columns (Fig. 5.2, a), strip slabs for columns and a wall (Fig. 5.2, b) and a common foundation slab over the entire area structural system (Fig. 5.2, c). For large slab thicknesses, more economical slabs than solid, ribbed and box-shaped slabs are used (Fig. 5.2, d, e). In weak soils, pile foundations are installed.

Rectangular columns (pylons) with an elongated cross section have ratios b/a<4 или hэт/b>4. Columns that are more elongated in plan should be classified as walls.

Beamless floors: a - smooth slab; 6 - plate with capitals

In multi-storey buildings, mixed column-wall CS are most often used.

It is recommended to design the load-bearing structural system in such a way that the vertical load-bearing elements (columns, walls) are located from the foundation one above the other along the height of the building, i.e. were coaxial. In cases where the columns and walls are not made along the same axis, the installation of stiffeners and beam-walls should be provided under the “hanging” columns and walls.

It is recommended to separate the structural system of buildings with settlement joints at different building heights, and also, depending on the length of the building, with temperature-shrinkage joints. The required distances between temperature-shrinkage joints along the length of the building should be established by calculation. During the construction period, it is possible to install temporary expansion joints, which are then eliminated.

Modern systems facade glazing

Heat transfer in translucent enclosing structures can occur through radiation, convection and thermal conductivity. The heat-protective properties can be changed by influencing these components of heat transfer.

There are several ways to influence the thermal characteristics of window structures:

─ increasing the number of layers of glazing, which is not effective enough, so

how it reduces the penetration of visible light through window structures;

─ change in the thickness of the gap between the glass panes (the thermal resistance of the air layer gradually increases to a certain thickness, and then practically does not change);

─ the use of filling the interglass space with various gases

or gas mixtures (today air is replaced with gases: argon, krypton, xenon, or a gas mixture formed in combination with air; when replacing air with argon, the thermal resistance of the interlayer increases by 10%);

─ the use of vacuum double-glazed windows (vacuum double-glazed window design

consists of two sheets of glass, soldered together with a small gap.

This design is highly durable. The use of special glass with a low-emission heat-reflecting coating to influence the radiant component of heat transfer and the combined use of the coating and gas filling (when using heat-reflecting coatings, there is a significant reduction in the amount of thermal energy lost in the form of infrared radiation through the surface of window glass that transmits visible and reflective infrared radiation. For by reducing the magnitude of the radiant component of heat transfer, heat loss through windows is significantly reduced, however, heat-reflecting coatings reduce the transmittance of light through windows. Coatings based on various metals are widely used as heat-reflecting coatings: silver, gold, copper with a system of antireflective oxides, semiconductor oxides of tin and indium) ; the use of electrically heated glazing (heating either the surface of the glass or the air space between the glass panes of the glass unit.

Other similar works that may interest you.vshm>
9749.		Development of an external lightning protection system for a complex of two buildings using a double rod lightning rod	97.3 KB
	Lightning protection device is a system that allows you to protect a building or structure from the effects of lightning. It includes external (outside a building or structure) and internal (inside a building or structure) devices.
229.		STATIC AND FRAME DESIGN DIAGRAMS	10.96 KB
	Frame structures STATIC AND STRUCTURAL DIAGRAMS OF FRAMES Frames are flat structures consisting of straight broken or curved span elements called frame crossbars and rigidly connected vertical or inclined elements called frame racks. It is advisable to design such frames for spans of more than 60 m; however, they can successfully compete with trusses and beams for spans of 24–60 m. Statically, frames can be three-hinged, double-hinged, or hingeless (Fig. Tri-joint...
2375.		ROAD CLOTHING. CONSTRUCTIVE DECISIONS	1.05 MB
	Certain features are associated only with the arrangement of layers in direct contact with the interlayer and the introduction of an additional operation for laying the geogrid. The last operation, due to the manufacturability of geogrids and the convenient form of their delivery, does not hold back the construction flow. In this regard, the accepted grip length is usually not related to the laying of the geogrid, but it is advisable to maintain a multiple of the grip length to the length of the material in the roll. It is recommended to reinforce asphalt concrete pavements by installing a layer of SSNPHAYWAY geogrid...
7184.		HEAT SUPPLY DIAGRAMS AND THEIR DESIGN FEATURES	37.41 KB
	In the initial stage of development of centralized heat supply, it covered only existing capital and separately constructed buildings in the areas covered by the heat source. Heat was supplied to consumers through heat inputs provided in the premises of house boiler rooms. Subsequently, with the development of centralized heat supply, especially in areas of new construction, the number of subscribers connected to one heat source increased sharply. A significant number of both central heating and heating substations have appeared at one heat source in...
230.		STATIC AND CONSTRUCTION DIAGRAMS OF ARCHES	9.55 KB
	According to the static diagram, arches are divided into three-hinged, double-hinged and hingeless. Double-hinged arches are less sensitive to temperature and deformation influences than hingeless arches and have greater rigidity than three-hinged arches. Double-hinged arches are quite economical in terms of material consumption, are easy to manufacture and install, and thanks to these qualities they are predominantly used in buildings and structures. In arches loaded with evenly distributed...
2261.		DESIGN AND POWER DIAGRAMS OF GROUND GTE	908.48 KB
	Single-shaft gas turbine engines The single-shaft design is classic for land-based gas turbine engines and is used throughout the entire power range from 30 kW to 350 MW. Using a single-shaft design, gas turbine engines of simple and complex cycles can be manufactured, including combined cycle gas turbine units. Structurally, a single-shaft ground gas turbine engine is similar to a single-shaft aircraft turboprop engine and a helicopter gas turbine engine and includes a compressor compressor and a turbine (Fig.
2191.		STRUCTURAL ELEMENTS OF AIR COMMUNICATION LINES	1.05 MB
	The supports of overhead communication lines must have sufficient mechanical strength, a relatively long service life, be relatively lightweight, transportable and economical. Until recently, overhead communication lines used supports made of wooden poles. Then reinforced concrete supports began to be widely used.
20041.		Electrical supply of civil buildings	221.94 KB
	Electricity supply is an integral part of every person’s life, because without electricity, life in every house, in every city apartment, will stop; the functioning of a single government institution is unthinkable - hospitals, post offices, kindergartens, schools and universities, giant factories. Electricity supply occupies a very important place in the lives of each of us, but it can only be entrusted to professionals.
6729.		Basics of inspection of buildings and structures	13.02 KB
	Fundamentals of inspection of buildings and structures Basic provisions Reliability is the property of a structure or structural element to fulfill specified requirements throughout the entire design service life for which they were designed while maintaining their performance characteristics. A defect is each individual non-compliance of the building structure of elements and parts with the requirements established by regulatory and technical documentation. Deformation, changes in the shape and size of the structure, changes in sediment stability, shear, roll, etc. Malfunction...
6744.		Methodology for conducting inspections of buildings and structures	13.91 KB
	Methodology for conducting an inspection of buildings and structures Monitoring of building structures of buildings and structures involves systematically conducting observation cycles, assessing and forecasting their technical condition for the timely adoption of measures to ensure the prevention of emergency situations; periodic inspections of buildings and their structures during scheduled and extraordinary inspections, as well as during a complete technical inspection housing stock; technical inspection of buildings for the design of major repairs...

The choice of one or another structural design of a building depends on its number of storeys, space-planning structure, availability of building materials and the base of the construction industry.

Structural diagram is a variant of a structural system based on the composition and placement in space of the main load-bearing structures - longitudinal, transverse, etc.

In frame buildings Three design schemes are used (Fig. 3.4):

With longitudinal arrangement of crossbars;

With transverse arrangement of crossbars;

Transomless.

Frame with longitudinal crossbar arrangement used in apartment-type residential buildings and mass public buildings with complex planning structures, for example, in school buildings.

Frame with transverse crossbar used in multi-storey buildings with a regular layout structure

Rice. 3.4. Structural diagrams of frame buildings:

a – with a longitudinal crossbar arrangement; b – with transverse; V -

without crossbar.

(dormitories, hotels), combining the pitch of transverse partitions with the pitch of load-bearing structures.

Transomless (beamless) frame, mainly used in multi-storey industrial buildings, less often in public and residential buildings, due to the lack of an appropriate production base in the prefabricated building housing construction and the relatively low efficiency of such a scheme.

The advantage of a non-transom frame is used in residential and public buildings when they are erected in prefabricated monolithic structures by lifting floors or floors. In this case, it is possible to arbitrarily install columns in the building plan: their placement is determined only by static and architectural requirements and may not obey the laws of modular coordination of steps and spans.

Variants of the frame structural diagram are presented in Fig. 3.5.

Fig. 3.5. Options for frame structural diagram:

A – with full; B – with incomplete; B – with a frame without crossbars; 1 – full frame with longitudinal crossbars; 2 – the same, with a transverse one; 3 – full frame with longitudinal arrangement of column crossbars (only at external walls) and long-span ceilings; 4 – incomplete longitudinal frame; 5 – the same, transverse; 6 – frame without crossbar; K – column; R – crossbar; J – vertical stiffness diaphragm; NP – flooring, NR – spacer flooring; I – load-bearing walls; II – curtain walls.

When designing buildings of the most common frameless system, the following five design schemes are used (Fig. 3.6):

scheme I– with a cross arrangement of internal load-bearing walls with a small pitch of transverse walls (3, 3.6 and 4.2 m). They are used in the design of multi-storey buildings, in buildings constructed in difficult soil and seismic conditions. Prefabricated floor structures used in mass construction, depending on the size of the span to be covered, are conventionally divided into small (2.4-4.5 m) and large (6-7.2 m) floors. ;

Fig.3.6. Structural diagrams of frameless buildings:

I – cross-wall; II and III – transverse wall; IV and V – longitudinal wall; A – options with non-load-bearing or self-supporting longitudinal external walls; B – the same, with load-bearing ones; a – plan of the walls; b – floor plan.

scheme II– with alternating sizes (large and small) of the pitch of transverse load-bearing walls and separate longitudinal stiffening walls (scheme with a mixed pitch of walls). Schemes I-II allow for a more varied solution to the layout of residential buildings, placing built-in non-residential premises on the ground floors, provide satisfactory planning solutions for children's institutions and schools;

scheme III – with sparsely spaced transverse load-bearing walls and separate longitudinal stiffening walls (with a large wall spacing). It has advantages when using fully prefabricated structures;

scheme IV – with longitudinal external and internal load-bearing walls and sparsely spaced transverse walls - stiffness diaphragms (every 25-40). They are used in the design of residential and public buildings of low, medium and high rises with stone and large-block structures. Rarely used in panel construction;

scheme V - with longitudinal external load-bearing walls and sparsely spaced transverse stiffening diaphragms. They are used in experimental design and construction of residential buildings with a height of 9-10 floors. Provides freedom in apartment planning.

The prefabricated monolithic structural system “KUB-2.5” is a further development of the “KUB” series systems with the aim of their further universalization for various construction conditions, improving design solutions, reducing labor costs for the manufacture and installation of elements and optimizing economic characteristics. The frame is assembled from prefabricated products, followed by monolithic assemblies; at the operational stage, the structure is monolithic.

Structural solutions of the KUB-2.5 system - joints of floor panels, joints of continuous multi-tiered columns, joints of floor panels with columns, trussed structures of 12-meter spans, etc. - provide frame and frame-braced systems for building frames. This became possible thanks to the analysis of the test results of full-scale fragments of joints of system elements, carried out by the dynamic testing laboratory at the center of construction examinations of the TsNIIEP housing under the leadership of Ph.D. Ashkinadze G.N. together with the authors of the systems. New structural elements developed in the KUB-2.5 system do not require the installation of formwork, which significantly reduces (by 60%) the volume of embedment concrete during installation. In addition, the design of the column joints eliminates the use of welding. All this reduces construction labor costs by 50-60% in comparison with the KUB-3 system. Experimental and theoretical studies conducted at the TsNIIEP Institute of Housing in the 70-80s confirmed the rigidity and strength qualities of the structure, as well as the reliability of the design premises.

The system is designed for the construction of buildings up to 15 floors high and involves the use of enlarged floor panels with maximum dimensions 2980x5980x160 mm, along with single-module dimensions 2980x2980x100 mm - depending on the lifting and transport capabilities of the contractors. The load-bearing capacity of the floors allows the use of the frame in buildings with a load intensity per floor of up to 1300 kg/m². The developed frame structures provide for floor heights in buildings of 2.8 m, 3.0 m and 3.3 m with a main grid of columns of 6.0x6.0 m. The use of frame schemes in buildings with columns with a cross section of 400x400 mm is limited to 5 floors under normal construction conditions and seismicity up to 7 points, and 3 floors with seismicity 8-9 points. In other cases, a frame-braced scheme using links or diaphragms is adopted. In buildings with a height of no more than 4 floors, columns with a section of 400x200 can be used, and the structural design must be frame-braced. For buildings with a height of more than 15 floors, individual design of columns is required. The developed frame elements make it possible to provide buildings with spans of 3.0 m, 6.0 m and 12.0 m. The need to implement other spans within the specified parameters requires individual developments.

One of the advantages of the frame is the reduced consumption of steel and cement per 1 m² of flooring compared to frame systems used both domestically and abroad. “The most important advantage of this system is its efficiency,” says CEO KUB company Gennady Grachev. — Due to the reduced consumption of concrete and steel, the total cost of the entire building is reduced by 5-7%, which, even if construction elements are manufactured using reinforced concrete structures, is a fairly decent amount. Moreover, the installation of such an object is very fast and very simple compared to traditional prefabricated frame systems. As an example, I note that a team of five people can install up to 300 m² of floors per shift! If the installers are well qualified, then the frame of one section of a high-rise building can be completed in two months.”

Technical and economic indicators per 1 m² of flooring of the KUB-2.5 system according to TsNIIPI “Monolit”, Moscow

Materials:

Labor costs, (person hours/m²)

Frame products have a limited number of standard sizes, which greatly facilitates its development. Elements of a transomless frame can be easily manufactured in newly developed areas, in the absence of an industrial base, as well as in places where the production of frames of existing series has not yet been established.

A transomless frame has architectural, planning and structural advantages over traditional beam frames. Features of KUB 2.5 that distinguish it from traditional prefabricated monolithic frame systems are the absence of crossbars, the role of which is played by floor slabs, and the use of multi-tiered columns without protruding parts. The form-building capabilities of the frame have a wide range from single-story to multi-story buildings with complex architectural and spatial solutions; in particular, a varied solution of facades is provided due to the ability to support the walls on each tier of the cantilever part of the reinforced concrete frame floor, in contrast to walls made of prefabricated panels.

The design of the frame makes it possible to solve a floor plan without consoles along the perimeter of the building. External self-supporting walls can be made of piece material or vertically cut panels that are attached to the outer floor chords.

The system has developed new design nodes for fastening connections to columns, reducing the likelihood of resonance of structures during forced vibrations (seismicity, wind, etc.). Therefore, it is a universal design for the construction of residential, public and some industrial buildings, both in normal construction conditions and in areas with seismicity up to 9 points on a 12-point scale.

The production division of the Glavstroy Corporation, OJSC Mospromstroymaterialy (MPSM), has been producing high-quality products for the construction of houses using the KUB-2.5 technology for a long time. A wide range of products is produced by Mospromzhelezobeton OJSC (MPZHB), which is part of the MPSM. As part of the program for the long-term development of production, carried out through own funds, in 2006, improvements to the products of the KUB structural system were carried out at MPZhB. Today, the plant is capable of producing about 250 thousand m per year using this technology and has experience in such supplies far beyond the capital region, for example, to Novy Urengoy. The company does a lot of work with the involvement of scientific institutes on the selection of concrete compositions, as well as the rational use of materials and electricity. During periodic meetings, representatives of NIIMosstroy noted the high quality of all the plant’s products.

This year it is planned to begin production of products of the KUB 2.5 system at the Adler Concrete Concrete Plant (an enterprise of the production division of Glavstroy). At the time of acquisition of the plant - early 2008 - it was not able to complete the entire range of work for the production of these products due to the lack of specialists and material and technical base. “Currently, the reconstruction program of this plant includes equipping leading European companies for the production of concrete pipes, rings and elements with equipment engineering infrastructure, - comments the head of the Marketing and Sales of Construction Materials Department, Alexander Khavanov. — It is planned to expand the production of reinforced concrete products for the construction of residential buildings of the 135 series and for structures for various purposes using KUB technology. Now work is underway to certify the series planned for construction in Sochi for seismic resistance, and MPZhB is already preparing equipment for the production of a wide range of products.”

The development of the KUB-2.5 system is currently underway: all frame elements have been processed and modernized, from the simplest embedded parts to the most complex elements - floor slabs. In addition to the release of the updated system, an electronic program will be released that will significantly simplify design in CUBE. Recycling of system elements will not lead to recycling of metal molds, which will give an advantage in the future to our clients who are already building and designing in KUB-2.5. The new development will be called KUB-4.

Currently, Glavstroy, based on MPSM, is conducting additional tests to prove that the system meets all modern customer requirements. For the tests, a 2-story frame with a foundation corresponding to a 20-story building was installed. This height is enough to evaluate the effect of loads, and the foundation will not distort the results - after all, during real construction it will be quite powerful. After the concrete has gained brand strength, the frame will be loaded, water tanks with a volume of 1 cubic meter in the amount of 225 pieces will create a vertical load, and with the help of 8 hydraulic jacks (the power of each is 200 tons), a horizontal load will be simulated, a dynamo will also be installed, which will create vibrations simulating a magnitude 8 earthquake.

“These are unique tests that have not been carried out in Russia for more than 20 years. Our frame holds 1.2 thousand kg per 1 m²,” notes Roman Smirnov, design engineer of the KUB company. “And when building housing, a load of 400 kg per 1 m² is usually taken into account.”

The KUB-2.5 system will also be checked for progressive collapse. This became relevant after the terrorist attacks on residential buildings. The tests will be carried out jointly with the Russian Earthquake Resistance Association, whose specialists will prepare an expert opinion by the end of August. And already in the fall it is planned to begin construction of buildings using the KUB-2.5 system in the Krasnodar Territory, which is an earthquake-prone zone.

Thus, the use of “CUBE 2.5” in housing construction allows for a new approach to the problems of housing design, taking into account its modern consumer qualities. After all, the use of this system guarantees a free layout of apartments and other premises in accordance with customer requirements. In addition, there is the possibility of using part of the floors for public premises, which does not require any additional processing of the frame structures.

Inset

Data obtained during construction residential complex for 356 apartments in Moscow on the street. cosmonaut Volkov:

• Installation of the frame by a team of 5 people - 300 m²/shift (slabs only); taking into account the installation of columns, reinforced concrete connections - 200 m²/shift;
• The metal consumption of the frame per 1 cubic meter of reinforced concrete (according to the Korenevo reinforced concrete plant) is 95.9 kg/cubic meter (10 and 12-story sections); 98.96 kg/cub.m - (16-storey section);
• Minimum set of metal molds for organizing production:
  — floor slabs measuring 3x3 m (with a plant capacity of 13,500 m²/year) — 9 pcs. (NP - 3 pcs. MP - 4 pcs. SP - 2 pcs.);
  - with 2-module floor slabs measuring 6x3 m - 4 pcs. (NP+MP - 2 pcs. MP+SP - 2 pcs.).

The structural system of a building is a set of interconnected load-bearing structures of the building, ensuring its strength, spatial rigidity and operational reliability. The choice of a building's structural system determines the static role of each of its structures. The material of structures and the technique of their construction are determined when choosing a building construction system.

The load-bearing structures of the building consist of interconnected vertical and horizontal elements.

Horizontal load-bearing structures - perceive all vertical loads falling on them and transfer them floor-by-floor to vertical load-bearing structures (walls, columns). Vertical structures, in turn, transfer the load to the foundation of the building.

Since ancient times, floor systems have been designed from a stereotypical approach to the layout of a beam cage, i.e. consisted of beams (crossbars) and flooring, which is how wooden floors are also structurally solved. Then reinforced concrete ribbed floor slabs appear, in which this approach is already merged into one structural element. The flat hollow-core floor slabs that appeared later are a significant step in the design of new types of building systems.

In industrial residential buildings, in comparison with traditional buildings that had mixed coverings that included fragments of wooden floors, horizontal load-bearing structures for the first time begin to play a role stiffness diaphragms In addition, floors perceive horizontal loads and impacts (wind, seismic, etc.) and transfer forces from these impacts to vertical structures.

The transfer of horizontal loads and impacts is carried out in two ways: either by distributing them to all vertical structures of the building, or to individual special vertical stiffening elements (walls, stiffening diaphragms, lattice wind braces or stiffening trunks). The industrial type of buildings also provides intermediate solutions - load transfer is possible with the distribution of horizontal loads in various proportions between stiffening elements and structures that work to absorb vertical loads.

Floors - rigidity diaphragms ensure the compatibility of horizontal movements of vertical load-bearing structures from wind and seismic influences. The possibility of compatibility and alignment of movements is achieved by rigid coupling of horizontal load-bearing structures with vertical ones.

As noted earlier, with a reduction in the construction volumes of buildings, the horizontal load-bearing structures of residential buildings with a height of more than two floors, in accordance with the requirements of fire safety standards, are made difficult to burn or non-combustible. These requirements, as well as the requirements of the economic stratum, are most fully satisfied by reinforced concrete structures, which determined their widespread use as horizontal load-bearing elements of all types of buildings. The floors are usually a reinforced concrete slab - prefabricated, precast, or monolithic.

Vertical load-bearing structures are distinguished by the type of structure, which serves as a defining feature for the classification of structural systems. On rice. 2 the main typological features of a residential building are given, the vertical load-bearing structures of which are continuous vertical plane of the walls. When using columns as the main vertical load-bearing elements of structures, already at the first stage of industrialization it was possible to obtain four structural schemes for a serial residential building: with a transverse arrangement of crossbars; with longitudinal arrangement of crossbars; with a cross arrangement of crossbars; crossbarless solution.

Industrialization made it possible not only to look at the work of floors from a new point of view, but also to significantly expand the typology of vertical load-bearing structures. With the development of serial housing construction, separate groups are distinguished the following types vertical load-bearing structures: block frame foundation development

planar (walls);

solid-section rods (frame struts);

volumetric-spatial (volumetric blocks);

volumetric-spatial internal load-bearing structures to the height of buildings in the form of thin-walled rods of an open or closed profile (stiffening trunks). The stiffening shaft is usually located in the central part of the building; Elevator, ventilation shafts and other communications are placed in the internal space of the shaft. In long buildings, several stiffening trunks are provided;

volumetric-spatial external load-bearing structures to the height of the building in the form of a thin-walled shell of a closed profile, which simultaneously forms the external enclosing structure of the building. Depending on the architectural solution the outer supporting shell may have a prismatic, cylindrical, pyramidal or other shape.

According to the types of vertical load-bearing structures, five main structural systems of buildings are distinguished: frame, frameless (wall), volumetric block, trunk and shell, otherwise called peripheral

The choice of vertical load-bearing structures, the nature of the distribution of horizontal loads and impacts between them is one of the main issues in the layout of a structural system. It also influences the planning decision, architectural composition and economic feasibility of the project. In turn, the choice of system is influenced by the typological features of the designed building, its number of storeys and engineering and geological conditions of construction.

The spatial frame system is used primarily in the construction of multi-storey earthquake-resistant buildings with a height of more than nine floors, as well as in normal construction conditions if there is an appropriate production base. The frame system is the main one in the construction of public and industrial buildings. In residential construction, the scope of its use is limited not only for economic reasons. The basis of fire safety requirements when designing residential buildings is the consistent creation of vertical fire barriers - firewalls. In a frame-type structure, the creation of firewalls was carried out by embedding fireproof vertical rigidity diaphragms between the columns. Thus, the possibilities of spatial planning, the main advantage of frame systems, were limited in advance.

The frameless system is the most common in residential construction; it is used in buildings of various planning types with a height of one to 30 floors.

The volumetric block system of buildings in the form of a group of individual load-bearing pillars made of volumetric blocks installed on top of each other was used for residential buildings up to 12 floors high in normal and difficult soil conditions. The pillars were connected to each other by flexible or rigid connections.

The barrel system is used in buildings with a height of more than 16 floors. It is most advisable to use a barrel system for multi-story buildings that are compact in plan, especially in earthquake-resistant construction, as well as in conditions of uneven base deformations (on subsiding soils, above mine workings, etc.).

The shell system is inherent in unique high-rise buildings for residential, administrative or multifunctional purposes.

Along with the main structural systems, combined ones are widely used, in which vertical load-bearing structures are assembled from various elements - rod and planar, rod and barrel, etc.

A partial-frame system based on a combination of load-bearing walls and frame that support all vertical and horizontal loads. The system was used in two versions: with load-bearing external walls and an internal frame, or with an external frame and internal walls. The first option was used when there were increased requirements for freedom of planning decisions for the building, the second - when it was advisable to use non-load-bearing lightweight structures of external walls and when designing mid- and high-rise buildings.

The frame-diaphragm system is based on the division of static functions between wall (bracing) and rod elements of load-bearing structures. All or most of the horizontal loads and impacts are transferred to the wall elements (vertical stiffening diaphragms), and predominantly vertical loads are transferred to the rod (frame) elements. The system is most widely used in the construction of multi-storey frame-panel residential buildings under normal conditions and in earthquake-resistant construction.

The frame-barrel system is based on the division of static functions between the frame, which perceives vertical loads, and the trunk, which perceives horizontal loads and impacts. It was used in the design of high-rise residential buildings.

The frame-block system is based on a combination of a frame and volumetric blocks, and the latter can be used in the system as non-load-bearing or load-bearing structures. Non-load-bearing volumetric blocks are used to fill the load-bearing frame lattice floor-by-floor. The load-bearing ones are installed on each other in three to five tiers on horizontal load-bearing platforms (floors) of the frame, located in increments of three to five floors. The system was used in buildings above 12 floors.

The block-wall (block-panel) system is based on a combination of load-bearing pillars made of volumetric blocks and load-bearing walls, floor-by-floor connected to each other by floor disks. It was used in residential buildings up to 9 floors high in normal ground conditions.

The shaft-wall system combines load-bearing walls and a shaft with the distribution of vertical and horizontal loads between these elements in various proportions. It was used in the design of buildings above 16 floors.

The trunk-shell system includes an outer load-bearing shell and a load-bearing trunk inside the building, working together to absorb vertical and horizontal loads. The compatibility of the movements of the trunk and shell is ensured by horizontal load-bearing structures of individual grillage floors located along the height of the building. The system was used in the design of high-rise buildings.

The frame-shell system combines the outer load-bearing shell of a building with an internal frame, with the shell working for all types of loads and impacts, and the frame working primarily for vertical loads. The compatibility of horizontal movements of the shell and frame is ensured in the same way as in buildings of the shell-stem system. Used in the design of high-rise buildings.

The concept of “structural system” is a generalized structural and static characteristic of a building, independent of the material from which it is constructed and the method of construction. For example, on the basis of a frameless structural system, a building with walls made of chopped wood, brick, or concrete (large block, panel or monolithic) could be designed.

In turn, the frame system can be implemented in wooden, steel or reinforced concrete structures. Options also arose when using various materials to fill the cells formed by load-bearing elements in frame or barrel buildings. For this purpose, any elements were used - from small-sized to volumetric block ones.

The load-bearing part of a shell building can be a braced or unbraced spatial steel truss, a monolithic reinforced concrete shell with regularly spaced openings, a precast monolithic reinforced concrete lattice, and so on. Combined structural systems were also multivariate. The areas and scale of application of individual structural systems in construction were determined by the purpose of the building and its number of storeys.

Along with the basic and combined ones, mixed structural systems are used in design, in which two or more structural systems are combined in height or length of the building. This decision is usually dictated by functional requirements. For example, if it was necessary to make a transition from a frameless system in the upper standard floors to a frame system on the first floors, i.e. if necessary, install a fine-cell planning structure on standard floors above the hall planning structure on non-standard floors. Most often, this need arises when setting up large stores on the first floors of residential buildings.

A structural diagram is a variant of a structural system based on its composition and type of placement in space of the main load-bearing structures, for example, in the longitudinal or transverse directions. The design diagram, like the system, is chosen based on initial stage design taking into account space-planning, structural and technological requirements. In residential frame buildings, four structural schemes are used: with transverse or longitudinal crossbars, a cross arrangement of crossbars, and without crossbars.

When choosing a structural design for the frame, economic and architectural requirements are taken into account: the frame elements should not bind the planning solution; the crossbars of the frame should not intersect the surface of the ceiling in living rooms, etc. Therefore, a frame with a transverse arrangement of crossbars is used in multi-story buildings with a regular planning structure (mainly dormitories and hotels), combining the spacing of the transverse partitions with the spacing of load-bearing structures. A frame with a longitudinal arrangement of crossbars was used in apartment-type residential buildings.

A transom-less (beamless) frame in residential buildings was used only in the absence of an appropriate production base and large house-building plants in a particular region, since for prefabricated housing construction such a scheme is the least reliable and most expensive. The transomless frame was mainly used in the manufacture of monolithic and prefabricated monolithic building structures using the method of raising floors.

A building system is a comprehensive characteristic of the structural design of buildings based on the material and technology of construction of the main load-bearing structures.

Construction systems of buildings with load-bearing walls made of bricks and small blocks of ceramics, lightweight concrete or natural stone are traditional and fully prefabricated.

The traditional system is based on the construction of walls using hand-masonry techniques, as has been done in all traditional buildings since ancient times. It should be noted that in an industrial building, only enclosing structures, floors and other internal load-bearing structures remain traditional - they are completely identical to fully prefabricated structures.

The prefabricated system is based on the mechanized installation of walls from large blocks or panels made in a factory from brick, stone or ceramic blocks. With the introduction of new housing series, the large-block system is almost everywhere giving way to the panel system.

The traditional system (with wooden floors), which has long been considered the main type of capital civil building of medium and high-rise buildings, is a thing of the past. As has been repeatedly emphasized, structures based on a fire scenario were called “traditional.” Only for the convenience of classifying the huge variety of industrial structures, traditional buildings are distinguished among them, only in appearance reminiscent of the previous brick structures erected before the end of the 50s.

By the mid-80s of the last century, about 30% of the construction volume of residential and 80% of mass public buildings were erected using the traditional system of enclosing structures. Of course, the level of industrialization of building structures of the “traditional” construction system as a whole is quite high due to the massive use of large-sized prefabricated products for floors, stairs, partitions, and foundations.

The industrial traditional system had significant architectural advantages. Thanks to the small size of the main structural element of the wall (brick, stone), this system allows you to design buildings of any shape with different floor heights and openings of various sizes and shapes.

The use of the traditional system was considered most appropriate for buildings that dominate the development. The structures of buildings with hand-masonry walls are reliable in operation - high-tech fired bricks did not require the installation of time-consuming, short-lived plaster, the fire resistance of industrial buildings was significantly increased brick walls. When designing them, new approaches were used to ensure durability and heat resistance.

Along with the architectural and operational advantages, manual masonry of walls is the cause of the main technical and economic disadvantages of stone buildings: the labor intensity of construction and the instability of the strength characteristics of the masonry depending on different batches of bricks in the event of minor deviations in the technological process at brick factories. The quality and strength of the masonry depended on the season of construction and the qualifications of the mason.

The large-block construction system was used to construct residential buildings up to 22 floors high. The mass of the prefabricated elements was 3-5 tons. The installation of large blocks was carried out according to the basic principle of erecting stone walls - in horizontal rows, on mortar, with mutual bandaging of the seams.

The advantages of a large-block building system are: simplicity of construction technology, due to the self-stability of the blocks during installation, the possibility of wide application of the system in conditions of different raw material bases. The flexible system of block nomenclature made it possible to build various types of residential buildings with a limited number of standard sizes of products. This system required less capital investment in the production base compared to panel and block house construction due to the simplicity and lower metal consumption of molding equipment, and the limited weight of prefabricated products made it possible to use common installation equipment of low load capacity.

The creation of a large-block building system was the first stage in the mass industrialization of building structures with concrete walls. Compared to the traditional stone system, the large-block system reduced labor costs by 10% and construction time by 15-20%. With the introduction of a more industrial panel system, the volume of use of large-block systems is gradually decreasing. Already by the mid-70s of the last century, the large-block system in mass housing construction ranks third in terms of volume of use after panel and traditional stone systems.

The panel building system is used in the design of buildings up to 30 floors high in normal ground conditions and up to 14 floors in seismic areas. The introduction of the panel system into housing construction began in the late 1940s simultaneously in the USSR and France. In 1967, GOST 11309-65, developed by the USSR State Construction Committee, came into effect for all types of large-panel houses, defining all the requirements for their quality, arrangement of joints and the degree of accuracy of production and installation of products.

The walls of such buildings are assembled from concrete panels one floor high, weighing up to 10 tons and 1-3 construction and planning steps long.

The technical advantage of panel structures is their significant strength and rigidity. This determined the widespread use of panel structures for high-rise buildings in difficult soil conditions (on subsiding and permafrost soils, above mine workings). For the same reason, panel structures demonstrate greater seismic resistance compared to other building systems.

In others economically developed countries The volume of panel construction is also growing rapidly, which is explained by the high economic efficiency of the construction system. However, it should be noted that by the beginning of the 80s, no country had such a powerful industrial base in the construction industry, and by the mid-80s, most Western countries were affected by a serious economic crisis.

A frame-panel building system with a load-bearing prefabricated reinforced concrete frame and external walls made of concrete or non-concrete panels is used in the construction of buildings up to 30 floors high. Introduced in the USSR along with panel construction in the late 1940s, until the early 90s, about 15% of the volume of public buildings were built annually on its basis. In housing construction, the system was used to a limited extent, since it was inferior to the panel system in terms of technical and economic indicators.

The volumetric block construction system was also first introduced by Soviet builders. Volumetric block buildings are erected from large volumetric-spatial reinforced concrete elements weighing up to 25 tons, enclosing a living room or other fragment of the building. Volumetric blocks, as a rule, were installed on top of each other without ligating the seams.

Volumetric block construction allows you to significantly reduce the total labor costs in construction (by 12-15% compared to panel construction) and obtain a progressive structure of these costs. If in panel construction the ratio of labor costs at the factory and construction site is on average 50 to 50%, then in volumetric block construction it approaches from 80% of factory production to 20% of labor costs at the construction site. Due to the complexity of the technological equipment, capital investments in the creation of volumetric block house-building factories are 15% higher compared to panel house-building factories.

The volume-block system is used for the construction of residential buildings up to 16 floors high in normal and difficult soil conditions and for low- and medium-rise residential buildings with a seismicity of 7-8 points. Volume-block housing construction is most effective when there is a significant concentration of construction, the need to carry it out in a short time, and when there is a labor shortage.

The frame is a system consisting of core load-bearing elements - vertical (columns) and horizontal beams (crossbars), united by rigid horizontal floor discs and a system of vertical connections.

The main layout advantage of frame systems is the freedom of planning solutions, due to sparsely spaced columns, having enlarged steps in the longitudinal and transverse directions. The system is characterized by a clear division into load-bearing and enclosing structures. The load-bearing frame (columns, crossbars and floor discs) takes up all the loads, and the outer walls act as enclosing structures, taking only their own weight (self-supporting walls). This makes it possible to use strong and rigid materials for load-bearing frame elements, and heat and sound insulating materials for enclosing ones. The use of highly efficient materials allows for a reduction in the weight of the building, which has a positive effect on the static properties of the building.

Frame As a rule, they construct public and administrative buildings. In recent years, frame multi-storey residential buildings have also been built. In buildings with full frame the load-bearing frame consists of columns and crossbars, made in the form of beams to support floor structures. Columns and crossbars fastened together form load-bearing frames that carry the vertical and horizontal loads of the building.

R The main enclosing elements are external walls External walls in buildings of this type are made mounted or self-supporting.

Curtain curtain walls in the form of hanging panels they are attached to the outer columns of the frame. Self-supporting external walls rest directly on foundations or on foundation beams installed along columnar foundations. Self-supporting walls are attached to the frame columns. In buildings with an incomplete frame, the outer walls are made load-bearing, and the columns are placed only along the internal axes of the building. In this case, crossbars are laid between columns, and sometimes between columns and external walls. This structural type of building modern construction has limited use.

A building of any type must not only be strong enough: not collapse under the influence of loads, but also have the ability to resist overturning under the action of horizontal loads, and have spatial rigidity, i.e. the ability, both as a whole and in its individual parts, to maintain its original shape under the action of laid forces.

The spatial rigidity of frameless buildings is ensured by load-bearing external and internal transverse walls, including the walls of staircases connected to external longitudinal walls, as well as interfloor ceilings connecting the walls and dividing them along the height of the building into separate tiers.

Structural diagram of buildings: a - with a full frame; b - with an incomplete frame; 1 - columns; 2 - crossbars; Z - floor panels; 4 - load-bearing external walls
A building with load-bearing external walls and an internal frame: 1 – load-bearing walls; 2 – walls of the staircase; 3 – columns; 4 joint of columns; 5 – crossbars (purlins); 6 – floor slab	Building with a full frame: 1 – columns; 2 – curtain walls; 3 – crossbars; 4 – walls of the staircase

Frame system most often used in the design of massive and unique public buildings for various purposes and number of floors. This system is inferior to the frameless system in terms of labor costs and construction time.

It is more difficult to heat a frame building, since the rooms are b O With a larger volume, it is more difficult to design a network of heating devices, taking into account sanitary and hygienic requirements. In principle, each individual room must have an individual heating and ventilation design, which creates certain difficulties for the building as a whole, significantly increasing the cost of design work, construction and operation. At the same time, the partitions have high thermal inertia, heating up much faster and giving off heat.

Taking into account all that has been said, until recently, frame systems were prohibited from being used in mass residential development. Frame structures were used mainly in the entertainment and exhibition parts of public buildings. At the same time, as a rule, the structural design of the structure was complex, that is, the frame system was combined with a frameless system in the administrative part - from the conditions of economic efficiency of construction and operation of the structure, its fire safety and environmental qualities.

However, the preference given to frame systems is associated with functional requirements for the flexibility of space-planning solutions of public buildings and the need for their repeated redevelopment during operation. From the point of view of freedom of planning, the possibility of creating long-span hall spaces - the layout advantages of frame systems over frameless ones are obvious.

At the same time, you should remember about the disadvantages of the frame system. On average, frame buildings are 3-7 times more expensive than frameless ones, as shown by a long-term analysis of technical and economic indicators for the 70-80s of the twentieth century, taking into account the industrial production of most load-bearing elements.

In a frame system it is much more difficult and expensive to create vertical fire barriers ( firewalls), therefore, during fires, as a rule, an entire tier of a frame building, limited by ceilings, burns out. This creates additional difficulties when designing escape routes.

Frame structural system: 1 – frame columns; 2 – frame crossbars; 3 – prefabricated flooring; 4 – external curtain wall panel	Frame diagram of a multi-storey building: 1- columns; 2 - crossbar; 3- floor slabs; 4-panel external walls
General view of buildings with a frame structural system: a – public; b – industrial	1 - support columns, 2 - floor slabs, 3 - load-bearing and tie beams, 4 - diaphragms for rigidity of escape routes, 5 - technological shaft, 6 - flights of stairs, 7 - self-supporting external walls

In frame buildings, the entire load is transferred to the frame, that is, a system of interconnected vertical elements (columns) and horizontal ones (purlins and crossbars).
Frames, used in civil engineering, are classified based on materials:

reinforced concrete frame, carried out in prefabricated, monolithic or prefabricated-monolithic versions;


metal carcass, often used in the construction of public and multi-storey civil buildings built according to individual projects;


wooden frame in buildings no higher than two floors.

reinforced concrete frame	metal carcass	wooden frame

According to the composition and location of the crossbars in the building plan in frame buildings
four design schemes are used :

— I – with transverse crossbars;

— II – with longitudinal crossbars;

— III – with cross-bar arrangement;

— IV –transomless.

The use of modern mass standard floor structures determines the dimensions of the main structural and planning grid of the frame axes 6x6 m (with an additional grid of 6x3 m).

When choosing a structural design for the frame, both economic and architectural and planning requirements are taken into account:

— frame elements (columns, crossbars, stiffening diaphragms) should not limit the freedom of choice of planning solution;

— the frame crossbars should not protrude from the ceiling surface in living rooms, but run along their boundaries.

	Structural diagram of a building with a frameless frame: 1 – frame columns; 2 – prefabricated or monolithic flooring
Frame system of buildings: a - with transverse arrangement of crossbars; b - with a longitudinal arrangement of crossbars; c - non-transom solution; 1 - self-supporting walls; 2 - columns; 3 - crossbars; 4 - interfloor slabs; 5 - above-column floor slab; 6 - intercolumn slabs; 7 - insert panel

Frame with transverse crossbars It is advisable in buildings with a regular planning structure (dormitories, hotels), where the pitch of transverse partitions is combined with the pitch of load-bearing structures.

Structural diagram of a frame building with transverse crossbars	Structural diagram of a frame building with a longitudinal arrangement of crossbars
	Four types of structural frame systems: a - with transverse arrangement of crossbars; b - with a longitudinal arrangement of crossbars; B - with a cross arrangement of crossbars; d - with a frame without crossbars, in which there are no crossbars, and the floor slabs rest either on the capitals of the columns, or directly on the columns. 1- foundation; 2 – fencing panels; 3 – columns; 4 – longitudinal crossbars; 5 – floor slabs (flooring); 6 – crossbars

Frame with longitudinal crossbars are used in the design of apartment-type residential buildings and mass public buildings with complex planning structures, for example, in school buildings.

Frame with cross-bars They are most often made monolithic and used in multi-storey industrial and public buildings.

Transomless frame used both in multi-storey industrial and civil buildings, because due to the absence of crossbars, this scheme is most appropriate in architectural and planning terms. In this case, there are no crossbars, and the prefabricated or monolithic floor disk rests either on the capitals (widening) of the columns, or directly on the columns.

By the nature of static work frame structural systems of civil buildings are divided into:

frame - with a rigid connection of load-bearing elements (columns, crossbars) at nodes in orthogonal directions of the building plan. The frame absorbs all vertical and horizontal loads.

frame-braced - with a rigid connection at the nodes of columns and crossbars in one direction of the building plan (creation of frame structures) and vertical connections placed perpendicular to the frame frames. The connections are rod elements (cross, portal) or wall diaphragms connecting adjacent rows of columns. Vertical and horizontal loads are absorbed by the frame frames and vertical pylons of rigid connections.

communication - They are distinguished by the simplicity of the design solution for connecting columns with crossbars, which provides movable (hinged) fastening. The frame (columns, crossbars) takes only vertical loads. Horizontal forces are transmitted to stiffening connections - stiffening cores, vertical pylons, rod elements.

Frame system
frame buildings have great rigidity, stability and create maximum freedom of planning decisions. The system ensures reliability in the perception of loads and uniform deformation of frames located in the building in the longitudinal and transverse directions. The disadvantage (with a prefabricated reinforced concrete frame) is the difficulty in unifying the node connections due to the different magnitudes of forces in them along the height of the building. This solution of a reinforced concrete frame, along with a steel one, is used in difficult soil conditions and in seismic areas.

When manufacturing a frame frame from prefabricated reinforced concrete, cutting its load-bearing elements into G-, T- And N-shaped elements, allowing the nodal connections to be transferred to the least stressed areas - places of zero bending moments from vertical loads.

Frame-bracing system provides spatial rigidity due to the joint work of transverse frames, vertical stiffening diaphragms and ceilings that perform the function of rigid horizontal disks. Vertical loads are transferred to the frame as a frame system. Horizontal loads acting perpendicular to the plane of the frames are perceived by vertical stiffening diaphragms and floor discs, and loads acting in the plane of the frames are perceived by a frame-bracing block consisting of vertical stiffening diaphragms and frame frames.

As a result of the theoretical studies, it has been proven that the frame-bracing system satisfies the condition of minimum material consumption in load-bearing vertical structures with zero rigidity of the transverse frames, that is, when the system turns into a pure communication

Communication system
all vertical loads are transferred to the core elements of the frame (columns and crossbars), and horizontal forces are absorbed by rigid vertical connecting elements (wall diaphragms and stiffening cores), interconnected by floor disks. In a braced frame, the strength and rigidity of the joints of the crossbars with the columns is limited. The nodes are designed to be flexible using steel ties (“fish”) that limit pinching.

The introduction of a bracing system into the production of prefabricated reinforced concrete frame elements made it possible to carry out a broad unification of its main elements (columns and crossbars) and their nodal connections.

In the 80s of the last century, a nomenclature of industrial reinforced concrete products of the 1.020-1 series was developed (Series 1.020-1/87 ), allowing the construction of both civil and industrial frame-panel buildings of any configuration and number of storeys. In addition to columns and crossbars, the series range includes floor panels, stiffening diaphragms and external walls.

Frames with longitudinal and transverse arrangement of crossbars can be designed from standardized elements.

Dimensional scheme are assembled under the following conditions:

the axes of columns, crossbars and stiffening diaphragm panels are aligned with the modular axes of the building;


the pitch of the columns in the direction of the span of the floor slabs is 3.0; 6.0; 7.2, 9.0 and 12.0 m.


the pitch of the columns in the direction of the span of the crossbars corresponds to 3.0; 6.0; 7.2 and 9.0 m.


the height of the floors in accordance with the purpose and the enlarged module ZM is 3.3; 3.6; 4.2; 6.0 and 7.2 m.

In addition, for apartment and specialized residential buildings (boarding houses, hotels, dormitories, etc.), the floor height is assumed to be 2.8 m.

The layout of stiffening diaphragms can be varied, but it is preferable to arrange spatial bracing systems with open or closed sections.

The spatial rigidity of frame buildings is ensured by:

the joint work of columns connected to each other by crossbars and ceilings and forming a geometrically unchangeable system;


installation of stiffening walls or steel vertical ties between columns;


pairing the walls of staircases with frame structures;


laying spacer panels in interfloor ceilings (between columns).

Structural elements. The columns have a height of 2-4 floors, which allows the use of jointless columns in buildings with the appropriate number of storeys.

Along with seamless columns, the range includes the following types of columns:

the lower ones are two floors high and the bottom of the column is located 1.1 m below the zero mark;


the middle ones are three to four stories high and the top ones are one to three stories high.

Columns with a section of 30x30 cm are provided for buildings up to 5 floors high and columns with a section of 40x40 cm for all others. Columns are available in double-cantilever and single-cantilever versions. Double-cantilever columns are installed along the middle and outer rows with curtain panels on the outer walls. Single-cantilever columns are placed along the outer rows with self-supporting external walls and along the middle rows with one-sided adjoining diaphragm walls in staircases. The joint is carried out by welding the fittings, followed by monolithification and its location above the plane of the console by 1050 mm.

Crossbars— T-section with a shelf at the bottom to support the floor slabs, which reduces its structural height. The joint of the crossbar with the column is performed with a hidden console and welding to the embedded parts of the console and column (partial pinching).

Floors - hollow-core slabs with a height of 220 mm and a span of up to 9.0 m. Slabs of type 2T are used for spans of 9 and 12 m. Floor elements are divided into ordinary and braced (spacer slabs). Tie floor slabs are installed between the columns in the direction perpendicular to the crossbars, ensuring their stability.

Floors experience transverse bending from vertical loads and bending in their plane from horizontal (wind, dynamic) influences.

The required rigidity of a horizontal floor disc assembled from prefabricated reinforced concrete elements is achieved by installing tie plates-spacers between columns, welding embedded connecting elements and installing keyed joints made of cement mortar between individual slabs. The resulting hard horizontal disk, perceiving all the loads, includes vertical stiffening diaphragms in joint work.

Walls are diaphragms the rigidities are mounted from concrete panels one floor high and 140 mm thick. and a length corresponding to the distance between the columns within the limits within which they are installed. With a column spacing of 7.2 and 9.0 m, diaphragm walls are designed as composites of two or three panels, with coordinate width dimensions of 1.2, 3.0 and 6.0 m. They can be blind or with one doorway. The elements of the stiffening diaphragms are connected to each other and the frame elements by welding embedded parts in at least two places on each side of the panel, followed by embedding.

The diaphragm pitch is determined by calculation, but does not exceed 36.0 m.

Exterior wall panels can be designed as self-supporting or non-load-bearing (suspended) structures. The walls are cut into panels in two rows. The range includes wall panels, under eaves, parapet, and plinth panels.

Self-supporting wall panels are installed using cement-sand mortar on plinth or wall panels and secured on top to the embedded parts of the columns. Non-load-bearing wall panels are hung on crossbars, consoles or supporting metal tables of columns and secured in the plane of the ceiling.

The binding of self-supporting and load-bearing wall panels to the frame is the same - with a gap of 20 mm between the outer edge of the column and the inner edge of the outer wall panel.

Insulation of panel joints is based on the principle of a closed joint

Compact in plan heated buildings up to 150 m long are designed without expansion joints. Buildings with an indented plan outline, which leads to weakening of the horizontal discs of the floors, are divided into temperature blocks, the length of which is linked to the division of the volumetric shape of the building, but does not exceed 60 m.

As in the 1.020.1 series, the KMS-K1 frame is assembled from columns, crossbars, floor slabs, stiffening panels and curtain panels of external walls.

Fragment of the facade of a frame building of series 1.020-1: A - diagram of cutting the outer wall into panels; a — sealing of vertical joints; b - fastening the top of the panel to the column; \ - protective layer; 2 - elastic mastic; 3 — elastic cord (gernite); 4 - column; 5 - brickwork; 6 - cement mortar; 7 - outer wall panel; 8 — steel embedded parts; 9 - steel connecting elements

Columns- they are made one- and two-story, of a single section of 400×400 mm, and their load-bearing capacity changes with changes in concrete grades and the percentage of reinforcement by transitioning from flexible (rods) to rigid (steel profiles) reinforcement. The series includes row columns, façade columns and columns with console overhangs of up to 1.2 or 1.8 m, which serve as supports for slabs of balconies and loggias.

The column joint is located 710 mm above the floor slab, which simplifies installation. When installing columns, special conductors are used to ensure alignment. The connection is made by welding the flat ends of the columns, followed by injection of cement mortar.

The crossbars are of T-section with a height of 450, 600 and 900 mm (the latter for spans of 12.0 m). The column is connected to the crossbar by resting it on a hidden (at the height of the crossbar) console and with partial pinching of a special “fish” gusset installed on the top flange of the crossbar, as well as by welding with the embedded elements of the column console. The values ​​of bending moments and tensile forces perceived by such a unit are limited by the yield strength of the “fish”. Therefore, in calculations when perceiving vertical loads, pinching of the crossbar on the support is not taken into account, considering it as a hinged connection.

There are ordinary and façade crossbars. The front crossbar has Z-shaped form, which is dictated by the peculiarity of its work - supporting the floor slabs on the lower shelf on one side and hanging the outer wall panels on the upper shelf on the other side.

Floors are made from hollow-core flooring with a height of 220 mm. Floorings are distinguished according to their placement in the plan - ordinary, facade, spacer flooring, sanitary and additional.

To create a single floor disc, the side surfaces of the decking have keyed grooves, which (after laying them out) are sealed, creating keyed seams that absorb shear forces.

Shear walls are designed from reinforced concrete panels one floor high and 180 mm thick. They have one or two shelves for supporting floor decks. The connection to the load-bearing elements of the frame is carried out using steel welded connections of at least two on each side.

Exterior wall panels can be cut horizontally or vertically along the façade plane of the building.

When cutting two-row (horizontal) panels, external wall panels are divided into belt (strip), wall and corner.

The coordination dimensions of horizontally cut external wall panels in length correspond to the pitch of the columns, and in height are 1.2; 1.5; 1.8 and 3.0 m. Wall panels can be as high as - 1.5; 1.8 and 2.1 m, and the width is a multiple of 300 mm module.

When cutting vertically, all panel dimensions in length and height are multiples of a 300 mm module.

The support unit for external wall panels is unified for different cutting systems on façade plane panels. The panels are supported on the supporting structure of the floor (crossbar or flooring) to a depth of 100 mm and welded using embedded and connecting elements at a distance of 600 mm in plan from the axis of the column. The top of the panel is attached to the column, also by welding the connecting elements.

Horizontal joints of external wall panels are made in quarters with an overlap of 75 mm. Insulation of vertical and horizontal interfaces of panels is carried out according to the principle of a closed joint

The system allows you to create multi-variant space-planning solutions through the use of columns with consoles of large overhangs (1.2 - 1.8 m) to create loggias, cantilever crossbars with an overhang of up to 3.0 m, forming protruding volumes. It is possible to construct halls with spans of 18.0-24.0 m. A variety of architectural compositions of buildings is achieved by using double-row (horizontal) and vertical cutting, as well as various options for protective and finishing layers of external wall panels.

KMC series frame - K1. The main planning situations of stiffening walls and load-bearing structures of floors: R - ordinary crossbar; RF - façade transom; NV - flooring; NRV - flooring-spacer; NRF - façade flooring-spacer; MF - facade wall panel; SG—stiffening wall; 1 - column with flat steel ends; 2 - semi-automatic submerged arc welding; 3 — steel centering gasket; 4 - embedded part; 5 — connecting strip; 6 - cement mortar; 7 — connecting plate; 8 - monolithic reinforced concrete; 9 - embedded part

Transomless frame. The main architectural disadvantage of frame systems for use in civil engineering is the beams-crossbars protruding into the interior from the plane of the floors. There are structural designs of frames that eliminate this drawback:

A system formed from prefabricated solid-section slabs supported on columns at the corner points of the column grid (KUB system);

Frame system with prestressed reinforcement in hidden crossbars formed under construction conditions (CPNS system).

System transomless frame CUBE is a prefabricated capitalless frame consisting of square columns and flat floor slabs.

Column grids of 6x3 and 6x6 meters, if necessary, can be increased to sizes of 6x9 and 9x12 meters. Section of columns 30x30 cm and 40x40 cm high in one or more floors with a maximum height of up to 15.3 m.

Floor slabs in plan size 2.8 × 2.8 m with a thickness of 16 to 20 cm. Depending on the location, they are divided into above-column, inter-column and insert slabs. The division of the floor into prefabricated elements is done in such a way that the joints of the slabs are located in zones with the lowest value (approximating zero) of bending moments from vertical loads.

The sequence of installation of the floor on the mounted columns is carried out in the following order: - above-column slabs are installed and welded to the column reinforcement, then inter-column slabs and, finally, insert slabs. Intercolumn and insert slabs have keys that make it easy to weld them together. After embedding the joints, a spatial rigid structure is created.

Transomless frame system (CUB): a - general view; b - installation sequence diagram; c - sectional diagram of the building

The advantage of the system is the absence of protruding elements in the ceiling plane and ease of installation using lightweight mobile cranes.

Transomless frame or frame-braced frame system civil buildings up to 16 floors high are designed for vertical floor loads of 1250 kg/m2. For heavy loads (2000 kg/m2), the number of storeys in the building is limited to 9 floors.

The system has architectural, planning and design advantages. A smooth ceiling makes it possible to flexibly decide on the layout of the internal space and create transformable rooms. Cantilever overhangs of floors provide flexibility in plastic solutions for facades.

The transomless frame is universal - it can be successfully used both in residential buildings and public (kindergartens, schools, retail establishments, sports and entertainment) structures, etc.

A system with hidden crossbars in the floor plane (CPNS) is designed according to a bracing scheme from prefabricated elements: columns, slabs, floors and reinforcement diaphragm walls. The connection between the prefabricated floor elements is carried out as a result of the construction of a monolithic crossbar with rope-tensioned reinforcement passed through through holes in the column in orthogonal directions. Prestressing of the reinforcement is carried out at the floor level, creating biaxial compression of the floor slabs

The floor slabs are 30 cm high and consist of a top slab 6 cm thick, a bottom slab 3 cm thick and crossed side ribs. During installation, the floor slabs are laid on temporary column capitals and supports, which are installed on the assembled lower level. Floor slabs can be made into a cell supported by columns at 4 corners or divided into two slabs connected by a monolithic reinforced seam. The structure, assembled from prefabricated elements of columns and floor slabs, works as a single static system that absorbs all force impacts due to the adhesion forces arising between individual prefabricated elements and the stresses of steel ropes.

Frame with hidden crossbars (CPNS): A - assembly diagram; B - floor plan node at the column; 1 - monolithic crossbar; 2 — monolithic seam; 3 - rope tension fittings: 4 - floor slab; 5 – column

A significant step back from the system of reliability and durability of industrial production of structural elements of frame buildings has been the return of “wet” processes to construction sites since the beginning of the 2000s. Monolithic beam and beamless frames have a low degree of manufacturability and do not allow the construction of approved types of enclosing structures.