Coating linkage system industrial buildings

The connections in the coatings are designed to ensure spatial rigidity, stability and immutability of the building frame, for the perception of horizontal wind loads acting on the ends of the building and lanterns, horizontal braking forces from bridge overhead and overhead cranes and their transfer to the frame elements.

Links are subdivided into horizontal(longitudinal and transverse) and vertical... The system of connections depends on the height of the building, the size of the span, the pitch of the columns, the presence of bridge cranes and their carrying capacity. In addition, the design of all types of ties, the need for their installation, their location in the coating is determined by calculation in each specific case and depends on the type of the supporting structures of the coating.

This section discusses examples of the structure of a system of ties in coatings with planar supporting structures made of metal, reinforced concrete and wood.

Ties in coatings with metal plane bearing structures

The system of connections in the coatings of buildings with metal farms depends on the type of trusses, step roof structures, conditions of the construction area and other factors. It consists of horizontal ties in the plane of the upper and lower chords of the truss trusses and vertical ties between the trusses.

Horizontal ties along the upper chords roof trusses are most often provided only if there are lanterns and are located in the under-lamp space.

Horizontal ties in the plane of the lower chords roof trusses are of two types. Connections first type consist of transverse and longitudinal trusses, spacers and guy wires. Connections second type consist only of transverse trusses, spacers and guy wires.

Cross trusses located at the ends of the temperature compartment of the building. If the length of the temperature compartment is more than 96 m, intermediate transverse trusses are installed every 42-60 m.

Longitudinal horizontal trusses along the lower belts of rafter trusses for the first type of ties, they are located in one-, two- and three-span buildings along the extreme rows of columns. In buildings with more than three spans, longitudinal tie girders are also placed along the middle rows of columns so that the distance between adjacent tie girders does not exceed two or three spans.

Connections first type are mandatory in buildings:

a) with bridge overhead cranes, requiring the device of galleries for passage along the crane tracks;

b) from under roof trusses;

c) with a design seismicity of 7 - 9 points;

d) with a mark of the bottom of the rafter structures of more than 24 m (for single-span buildings - more than 18 m);

e) in buildings with a roof on reinforced concrete slabs equipped with overhead traveling cranes general purpose with a lifting capacity of more than 50 tons with a truss pitch of 6 m and a lifting capacity of more than 20 tons with a truss pitch of 12 m;

f) in buildings with a roof on steel profiled decking -

in one- and two-span buildings equipped with overhead traveling cranes with a lifting capacity of more than 16 tons and in buildings with more than two spans with overhead traveling cranes with a lifting capacity of more than 20 tons.

In other cases, links should be applied second type, while with a pitch of trusses of 12 m and the presence of longitudinal half-timbered racks along the columns of the extreme rows, longitudinal tie trusses should be provided.

Vertical links are located at the locations of transverse trusses along the lower belts of roof trusses at a distance of 6 (12) m from each other.

Mounting fasteners of ties to the coating structures are accepted on bolts or by welding, depending on the magnitude of the force effects. Tie elements are designed from hot-rolled and bent-welded sections.

Figures 5.2.1 - 5.2.10 show the layouts of the connections in the cover with trusses from paired corners. Ties in coatings using wide-flanged tees, wide-flanged I-beams and round pipes are solved in a similar way. Constructive solution vertical ties with a span of 6 and 12 m are shown in Figures 5.2.11, 5.2.12

Connections in the roofing with trusses made of closed bent-welded profiles of the "Molodechno" type are shown in Figures 5.2.13 - 5.2.16.

The basis of the invariability of the coating in the horizontal plane is a solid disc formed by a profiled flooring fixed along the upper chords of the trusses. The flooring unties the upper chords of the trusses from the plane along the entire length and absorbs all horizontal forces transmitted to the covering.

The lower chords of the trusses are untied from the plane by vertical ties and struts, which transfer all efforts from the lower chord of the trusses to the upper disc of the covering. Vertical ties are established after 42 - 60 m along the length of the temperature compartment.

In buildings with pavement structures of the "Molodechno" type with a slope of the upper belt of 10%, the arrangement of vertical braces and struts is similar to that shown in Figures 5.2.14 - 5.2.16. The vertical connection in this case is performed by a V-shaped span of 6 m (Fig. 5.2.11).

Figure 5.2.5. Layouts of vertical ties in coatings

with the use of profiled flooring

(the cuts are indicated in Fig. 5.2.1, 5.2.2)

Figure 5.2.8. Layout of vertical ties in coatings using reinforced concrete slabs

The forces from the wind load acting on the outer walls are collected in the planes of the ceilings and coverings and are then transmitted to vertical elements supporting frame... In most cases, the supporting structures of the floors and roofs form rigid disks capable of transferring wind loads from the outer walls to the building frame. Otherwise, special horizontal connections are required. In multi-storey buildings horizontal links it is enough to have every second or third overlap in the plane. Load bearing capacity of columns in most cases is sufficient to absorb the wind load from the cargo area with a height of two to three floors.

Floor slabs can perform the functions of horizontal wind ties only after they acquire the required strength after concreting, therefore, temporary ties are required during the installation of the frame, which can later be removed.

Wind connections are not required over the entire area of ​​the covering or interfloor overlap, but their placement should be such that the transfer of horizontal forces to vertical ties.

1. Vertical braces are located around the staircase in three planes. Horizontal truss truss longitudinal direction the building is formed by setting the braces between the randbeams and the belt in parallel outside wall... A transverse horizontal truss is formed between two floor beams that serve as its chords.

2. Vertical connections in planes end walls and between the two inner columns. The horizontal truss in the longitudinal direction of the building is formed between the beams and the girders running in the plane of the vertical braces. The belts of the transverse truss are two floor beams.

3. Vertical ties in the planes of the end walls and between two internal columns. A horizontal truss in the longitudinal direction of the building is formed between two rows of internal columns ( good decision when planning a centrally located corridor).

A transverse horizontal truss is formed between the two middle rows of floor beams.

4. Horizontal ties in the plane of the upper chords of floor beams and round beams. Braces from the corners. The gusset and bolt heads can interfere with the installation of corrugated decking.

5. Ties are installed in the plane of the lower chord of the floor beam.

6. Fastening of the braces from the corners at the junction point of the randbeam and the floor beam to the column.

7. In the absence of a longitudinal beam, which is at the same time a chord of a braced truss, it is necessary additional element(here is one channel).

8. Fastening intersecting tie rods to the floor beam.

9. If the floor beams lie on the girders, then the best solution will place the ties in the plane of the lower chords of the beams.

To ensure spatial stability metal structures, special steel elements are used - vertical ties between the columns. The production association "Remstroymash" offers metal structures self-made for various manufacturing and construction companies.

The assortment of the enterprise:

• Rods.
• Beams.
• Farms.
• Frames and other communication systems.

The main purpose of steel structures ties

With the help of the lungs structural elements spatial systems with unique properties are formed:

• bending and transverse torsional rigidity;
• resistance to wind loads, inertial influences.

When assembling, the connecting systems perform the listed functions aimed at increasing the resistance against external influences. Wind ties of metal structures give the finished structures additional sail stability during operation. Spatial rigidity and stability of buildings, columns, bridges, trusses, etc. is ensured thanks to the ties installed in the horizontal planes in the form of upper and lower belts.

At the same time, at the ends and in the intervals between the spans, special connections of vertical metal structures - diaphragms - are established. The resulting system of ties provides the required spatial rigidity of the finished structure.


Cross bracing of superstructures
a - the construction of the main knots of connections; b - cross-link diagram

Types of connections of metal structures

Products differ in manufacturing and assembly methods:

• Welded products.
• Prefabricated (bolted, screw).
• Riveted.
• Combined.

Materials for the manufacture of binding metal structures are black and stainless steel... Thanks to the unique technical specifications, stainless steel products do not require additional processing against corrosion.

Diagrams are vertical connected:
A cross; B two-tier cross, C - diagonal inclined, D - multi-tiered diagonal inclined

Link examples

CONNECTED CONSTRUCTION DIAGRAM OF FRAME BUILDINGS

FRAME-LINKED CONSTRUCTION DIAGRAM OF FRAME BUILDINGS

FRAME CONSTRUCTION DIAGRAM OF FRAME BUILDINGS

For the construction of multi-storey P. z. mainly reinforced concrete frame-type frames are used, which perceive horizontal forces by rigid frame nodes or solved according to a frame-link scheme with the transfer of horizontal forces to diaphragms, walls stairwells and elevator shafts. The frames of multi-storey floors are usually prefabricated or prefabricated-monolithic with beam or bezel-less structures of interfloor floors.

The frame scheme of the frame bearing frame of buildings is a system of columns, beams and floors, connected in structural units into a rigid and stable spatial system that perceives horizontal (wind and other) forces. The spatial frame of the bearing frame with a frame scheme must have the necessary rigidity not only in one plane , but also in the perpendicular direction, which is achieved by a rigid solution of all nodal joints of vertical and horizontal structural elements both in the longitudinal and transverse directions.

The frame frame of a multi-storey building can be made in monolithic and prefabricated reinforced concrete or in steel structures which in order to fire safety the object must be covered with concrete.

The rigidity and stability of the frame building is ensured by the solution of its supporting frame according to the frame, tie or frame-tie scheme. The frame-tie scheme (see the figure on the right) consists of a number of flat frames located in vertical planes all transverse axes. Frames provide lateral rigidity and stability to the building, but limit the freedom of floor planning. Longitudinal stiffness is achieved by introducing in some areas vertical walls rigidity. Stiffening walls are made of reinforced concrete panels. They are inserted into the gaps, bounded on both sides by columns, and from above and below by floor beams. The stiffening walls are installed one above the other over the entire height of the building. That, in combination with hard disks of the floors, forms a stable frame skeleton. V w-b walls stiffness, openings for doors or windows can be installed, provided that the hole is reinforced with a framing board with additional reinforcement according to the calculation. The verticality of the transverse floor frames of the frame is ensured by longitudinal stiffening walls. Hard disks of intermediate floors and coverings, mounted from large panels, fix the straightness of the girders along their entire length and their parallelism to each other. The stiffness of the floors is ensured by connecting the tie and ordinary panels to each other and the crossbars by welding the embedded parts and filling the seams with mortar into a single piece HDD the same as in large-panel buildings... In the load-bearing frame of a multi-storey frame building, in which transverse stiffening walls are placed along each transverse row of columns, all transverse frames do not have crossbars, and the floor panels rest directly on the stiffening walls in the same way as in large-panel houses, which partially relieves columns from vertical loads.

The frame-link scheme is used mainly in the construction of residential multi-storey buildings (hotel type), administrative, etc.

The link scheme differs from the frame one in that the structural units in it can have not only a fixed - rigid, but also a movable - hinge solution, and all horizontal forces are completely transferred to the system of additional stiffness links.

There are three options for stiffening ties: in the form of inclined (most often diagonal) braces with tensioners(4), rigid oblique rods which, after installation and embedment, form a stiffening wall (5), prefabricated walls or stiffening panels mounted from reinforced concrete slabs inserted between the uprights and crossbars of the frame (5) with rigid attachment to them (by welding or by bolts) in at least eight places - two attachments on each side of the panel outline. In buildings with a braced frame, the stiffening walls are spaced at intervals of several design steps (second figure). This allows, if necessary, on each floor to allocate large rooms (with rarely standing racks) for scientific, design organizations, etc., as well as sales areas department stores, etc. The skeleton of the bonded type has wide application in the construction of multi-storey, high-rise, as well as high-rise residential and public buildings.

Vertical braces between steel columns a - brace braces; b - cross; в - portal; 1 - axis expansion joint; 2 - communication block; 3 - crane beams; 4 - spacers

The link scheme differs from the frame one in that the structural units in it can have not only a fixed - rigid, but also a movable - hinge solution, and all horizontal forces are completely transferred to the system of additional stiffness links. There are three options for stiffening ties: in the form of oblique (most often diagonal) stretch marks with tensioning devices (4), rigid oblique rods that, after installation and embedding, form a stiffening wall (5), prefabricated walls or stiffening panels mounted from reinforced concrete slabs, inserted between the posts and crossbars of the frame (5) with rigid attachment to them (by welding or by bolts) in at least eight places - two attachments on each side of the panel outline. In buildings with a braced frame, the stiffening walls are spaced at intervals of several design steps (second figure). This allows, if necessary, on each floor to allocate large rooms (with rarely standing racks) for scientific, design organizations, etc., as well as sales areas of department stores, etc. also high-rise residential and public buildings.

In a braced frame, the connection of columns and girders is hinged, therefore, vertical stiffness ties (cruciform, portal, etc.) or stiffening diaphragms (special reinforced concrete partitions) are required. The interconnected floor slabs form a rigid horizontal element of the building.

Longitudinal stability of steel columns is ensured by vertical ties between the columns. Ties are placed in the middle of a building or temperature compartment. When the length of the building or temperature compartment is more than 120 m, two systems of vertical ties are placed between the columns.

Vertical braces between steel columns a - brace braces; b - cross; в - portal; 1 - axis of the expansion joint; 2 - communication block; 3 - crane beams; 4 - spacers

Most simple circuit vertical ties are cross. With a small step, but high altitude columns, two cross ties are installed along the height of the lower part of the column. Vertical ties are placed along all rows of the building. With a large pitch of the columns of the middle rows, and also, in order not to interfere with the transfer of products from span to span, portal links are constructed. The connections between the columns at the level of the supporting parts of the trusses in the connecting block and end steps are designed in the form of a farm, and spacers are placed in the rest of the places.

The connections for the structure of the building covering to ensure the spatial rigidity of the frame are located:

In the plane of the upper chords of the truss trusses - transverse tie trusses and longitudinal struts between them;

In the plane of the lower chords of the truss trusses - transverse and longitudinal trusses;

There are vertical ties between the trusses in the ridge plane;

Along the lanterns - horizontal ties at the level of the upper belts of the lanterns and vertical ties between the lanterns (as well as ties between trusses).

Coverage connections: a - along the upper belts of the trusses; b - along the lower belts of the trusses; c - vertical ties between farms

They carry out connections from corners or channels. The ties are fastened with bolts and sometimes rivets.

8. VOLUME-BLOCK CONSTRUCTION SYSTEM OF BUILDINGS (16)

2.3.2. Links between columns

The purpose of the ties: 1) creation of the longitudinal rigidity of the frame, necessary for its normal operation; 2) ensuring the stability of the columns from the plane of the transverse frames; 3) the perception of the wind load acting on the end walls of the building, and the longitudinal inertial effects of bridge cranes.

Ties are established along all the longitudinal rows of the columns of the building. Diagrams of vertical connections between the columns are given in Figure 2.34. Schemes (fig. 2.34, c, d, f) refer to buildings without crane or with overhead crane equipment, all the rest - to buildings equipped with overhead traveling cranes.

In buildings equipped with overhead support cranes, the main ones are the lower vertical braces. They are combined with two columns, crane beams and foundations (Fig. 2.34 d, w ... l) form geometrically unchangeable disks fixed in the longitudinal direction. The freedom or constraint of deformation of other frame elements attached to such disks substantially depends on the number of rigid blocks and their location along the frame. If you place the link blocks along the ends of the temperature compartment (Fig. 2.35, a), then with an increase in temperature and the absence of freedom of deformations ( t 0), loss of stability of compressed elements is possible. That is why vertical braces are best placed in the middle of the temperature block (fig. 2.34, a ... in, rice. 2.35, b), ensuring freedom of temperature movements on both sides of the link block (Δ t 0) and eliminating the appearance of additional stresses in the longitudinal elements of the frame In this case, the distance from the end of the building (compartment) to the axis of the nearest vertical bond and the distance between the bonds in one compartment should not exceed the values ​​given in Table. 1.2.

In the above-crane part of the columns, vertical braces should be provided at the ends of the temperature blocks and at the locations of the lower vertical braces (see Fig. 2.34 a, in). The expediency of installing the upper ties at the ends of the building is primarily due to the need to create the shortest path for transmitting the wind load R w to the end of the building along the longitudinal tie elements or crane beams on the foundations (Fig. 2.36). This load is equal to the support reaction of a horizontal tie truss (see Fig. 2.30) or two trusses in multi-span

Rice. 2.35. Influence of layouts of bonded blocks on the development of thermal deformations:
a- when the link blocks are located at the ends; b- the same, in the middle of the building

buildings. Similarly, the forces from the longitudinal braking of the cranes are transmitted to the foundations. F cr(fig. 2.36). The design force of longitudinal braking is taken from two cranes of one or adjacent spans. In long buildings, these forces are distributed equally to all vertical trusses between the columns within the temperature block.

The structural diagram of the connections depends on the pitch of the columns and the height of the building. Various options the solutions of the connections are shown in Fig. 2.34. The most common is the cross pattern (Fig. 2.34, r-i), since it provides the simplest and most rigid tie-in of the building's columns. The number of panels in height is assigned in accordance with the recommended angle of inclination of the braces to the horizontal (α = 35 ° ... 55 °). When it is necessary to use the space between the columns, which is often due to technological process, the links of the lower tier are designed with portal (Fig. 2.34 To) or semi-portal (see Fig. 2.34, l).

Vertical ties between the columns are also used to secure spacers in the nodes (Fig. 2.34 e ... and), if they are provided to reduce the calculated column lengths from the frame planes.

In columns with a constant section height h≤ 600 mm, ties are placed in the plane of the column axes; in the stepped communication columns above

Rice. 2.36. Transmission schemes for wind (from the end of the building) and longitudinal crane loads:
a, b- buildings with overhead traveling cranes; c, d- buildings with overhead cranes

braking structure (upper vertical braces) at h≤ 600 mm are installed along the axes of the columns, below the crane girder (lower vertical ties) at h> 600 mm - in the plane of each shelf or column branch. The tie nodes between the columns are shown in Fig. 2.37.

Ties are fastened on bolts of coarse or normal accuracy and, after alignment of the columns, can be welded to the packings. In buildings with overhead cranes of operating modes 6K ... 8K, the gussets of the connections should be scalded or joints should be made with high-strength bolts.

When calculating connections, you can use the recommendations of clause 6.5.1.