Bearing structures - a set of structures of a building or structure , which, statically interacting, withstand loads, provide strength and stability of the building. The remaining structures of the building are called enclosing (self-supporting).
The main structures that take up the loads that arise in the building make up the supporting frame , that is, the combination of horizontal ( floor ) and vertical ( walls , poles , racks, columns , etc.) (sometimes inclined) structural elements. In addition to the skeleton, foundations are considered to be load-bearing structures (they take the load of the load-bearing skeleton and distribute them to the base of the building , for example, to the bearing soil ), stairs , roof (a flat roof is sometimes referred to as ceilings).
Content
Classification of loads
The loads to which the supporting structures must counteract are divided into:
- constant - own weight of the structures of buildings and structures, soil pressure on the walls of the basement, as well as stationary walling, finishing and other materials;
- temporary (long and short-term) - loads from the weight of people, furniture, stationary equipment, property located in a building stationary (liquids, bulk solids, gases), prolonged temperature, snow and wind effects;
- crane - loads from braking of the crane truck, movement and braking of the crane itself;
- special (special) - loads from explosions, accidents, precipitation and subsidence of soils, seismic effects, vibration of equipment, etc.
Settlement
When calculating structures, one can be guided by different criteria and requirements. Until 1955, the USSR used calculations for permissible stresses . The requirement was fulfilled that the designed structure of the smallest possible cross section retained its strength. In fact, a single safety factor was used for all structures, regardless of the method of their use and working conditions [1] .
Since then, the method of calculating limiting states has begun to be applied, taking into account the requirements of normal operation. Such a method takes into account three limit states (PS) depending on three requirements for the structures [1] .
- 1PS - by bearing capacity . The calculation was to guarantee the strength, stability and endurance of the structure.
- 2PS - for deformation and displacements. For example, the ceiling can bend so that it does not lose its strength, but from an operational point of view it will cause a number of problems, such as the destruction of walling, curtain walls, partitions.
- 3PS - for crack resistance. The magnitude of crack opening is limited or their formation is not allowed so that there is no threat to the operation of the structure due to loss of impermeability, corrosion of elements or local damage.
The greatest loads, the occurrence of which will not interfere with operation, are called normative. The product of the standard loads by the overload coefficient is called the design loads [1] .
Based on the classification of loads, all loads can act simultaneously. Therefore, the calculations take into account different combinations of loads (basic, additional and special). The main combination includes all permanent loads, temporary long-term and one short-term, which has the greatest impact. Additional combinations contain all long, temporary long and all short-term loads. In special combinations, one of the special loads is added [1] .
See also
- Frame (construction)
Notes
- β 1 2 3 4 S.I. Weidman , L.F. Teverovsky, D.V. Yakovlev. Building construction. - Leningrad: Publishing house of building literature, 1970. - 344 p.
Literature
- Team of authors Dr. arch. prof. M.S. Tupolev, Assoc. A. N. Shkinev, prof. A.N. Popov, Ph.D. arch. Assoc. A. A. Popov, Ph.D. tech. Sciences Assoc. Yu. L. Sopotsko, Ph.D. arch. Assoc. T. I. Kirillova, Ph.D. arch. V.N. Kartsev, Ph.D. arch. O. V. Koretko, engineer I.A. Brownsdorfer, Ph.D. tech. Sciences V.V. Bespalov, Ing. V.M. Kunin. Construction of civil buildings / edited by M. S. Tupolev, scientific editor - arch. G.A. Dovzhik. - Moscow: Publishing house of building literature, 1968. - 239 p.
- S.I.Vaidman, L.F. Teverovsky, D.V. Yakovlev. Building construction. - Leningrad: Publishing house of building literature, 1970. - 344 p.
Links
- Supporting structures - an article from the Great Soviet Encyclopedia .