DETERMINATION OF THE AMOUNT OF LOAD ON PROTECTIVE STRUCTURES OF CIVIL DEFENSE AGAINST THE INFLUENCE OF A SHOCK WAVE ACCORDING TO DBN V.2.2-5:2023

Abstract

The main types of explosions and their differences between each other are considered, as well as the difference in excess pressure in the air shock wave is shown. The definition of the calculated load on various load-bearing elements depending on the type of building, its location and structural inhomogeneities of building structures according to DBN B.2.2-5:20023 [1] is given. One of the extreme effects, the danger of which must be taken into account when designing protective structures of civil protection, is an external explosion, which can be caused by both man-made and military factors. The explosion generates a whole complex of loads and impacts. The pressure at the front of the air shock wave, as well as the duration of the compression and rarefaction phases, depend on the amount of explosives and the distance to the center of the explosion or cloud boundary. In general, a detonation explosion is characterized by the possibility of significant pressure on the front of the air shock wave and the short duration of the action (tenths and even hundredths of a second). The air shock wave, when interacting with the structure, affects its above-ground and underground parts. This process is complex: at the beginning of the interaction process, the air shock wave affects the external structures of the above-ground part of the building and the surface of the soil in front of the building, causing a compression wave in it, which, in turn, affects the front outer face of the underground part. Further, the air shock wave, passing through the structural inhomogeneities of building structures in the form of window and door openings, affects the internal load-bearing and non-load-bearing structures of the building, as well as the covering of the underground part. At the same time, compression waves in the soil affect the side and rear walls of the underground part.