Concentrations of halls: a), b) the roof, c), d) walls; 1 - transverse tombstone, 2 - longitudinal roof braces, 3 - transverse brace at the level of the lower truss chord, 4 - vertical brace of the gable wall, 5 - vertical brace of wall columns, 6 - longitudinal braces at the level of the lower truss chord, 7 - vertical braces of trusses, 8 - horizontal bracing of the gable wall, 9 - horizontal braces of the longitudinal wall.
Larger column spacings with a smaller spacing of girders were obtained by using lattice trusses in the longitudinal axes of the hall, on which the intermediate roof trusses are based.
The transverse stiffness of the hall is ensured by frames made of mullions and lattice transoms, and in the longitudinal direction, the poles, longitudinal trusses and beams.
All halls should be properly braced, that the structure does not lose its stability during assembly and use. The figure above shows the types of braces used in hall construction.
Scheme of supporting the gable wall on horizontal braces: a) reinforced concrete cover, b), c) steel cover; 1 - gable wall, 2 - girders, 3 - reinforced concrete slabs, 4 - roof ridge, 5 - horizontal bar of the girder, 6 - light coatings
The support of the gable walls on the upper edge is shown in the figure. The horizontal force from the wind acting on the gable wall should be transferred to the horizontal braces, which are placed in the roof slope or in the level of the lower flange of the girders. Horizontal braces transmit this force to the vertical braces of the longitudinal walls.
If the hall covering is made of reinforced concrete slabs and constitutes a rigid roof shield, then this shield can carry horizontal loads and transfer them to the extreme supports.
Covering large span halls may be made of flat elements and frames, arcs or in the form of meshes one- or two-curvature.
Exhibition pavilion in Brno (Czechoslovakia) it is covered with a mesh dome with a span 93,5 m and the arrow 19,7 m made of three sets of pipes specially bent to the shape of the rotating surface of the dome. The single-layer three-way mesh consists of bars arranged along a helix on the surface of the sphere, parallel bars run at the intersection. The rods are connected by means of crosspieces. The dome is covered with sheet steel and transparent plastic laminates.
Rod systems have been widely used in the construction industry for several decades, the so-called. structural. Structural structures are used both for flat covers, as well as for curved covers. There are many solutions for structural covers with spans above 60,0 m.