Method of the calculated estimation of the possibility of progressive destruction of buildings in result of fire

Abstract

When analyzing the fire safety of building structures, in addition to considering their fire resistance, the limits of flame expansion and other fire-safety engineering features, there should be considered also the probability of their progressive collapse in case of a damage caused to some their elements. In case of progressive collapse of the building structures, socio-economic losses become the worst possible. The article proposes a method of calculation for the estimation of the possibility of progressive destruction. The method is based on the assumption that one or several compressed elements are damaged and must be removed from the system, which ensures the rigidity and geometric immutability. The basic point of the method is the hypothesis of formation of the line of plastic hinge joints in the ceiling plate. The estimation of the possibility of progressive destruction is made according to the energy criterion on the basis of a comparison of the work of internal and external forces on the possible movements of the system, which, under these conditions, is geometrically variable. The proposed method is productive and economical comparing to the existing methods which involve complex mathematical models and software complexes.