Determination of stiffness parameters of reinforced concrete structures using the decomposition method for calculating their survivability

Abstract

A method for determining the generalized stiffness of reinforced concrete structural systems of monolithic buildings using the decomposition method is presented. The secondary calculated scheme for determining dynamic additional loading in the frame of a monolithic building is adopted in the form of a substructure isolated from the frame of a building in the zone of possible local failure under a special action. For such a system, generalized stiffnesses are defined, depending on the angular stiffness of the support restraints and the stiffness of the overlying floors (adjacent structural elements). Analytical dependencies and a method for determining the overall stiffness of reinforced concrete substructures with specified boundary conditions are proposed. The influence of boundary conditions on internal force factors of the substructure is investigated. Recommendations are given for improving the survivability of the considered structural systems of monolithic buildings, as well as suggestions for their protection from progressive collapse.