Influence of Floor Slabs to the Progressive Collapse-Resistant Ability of Reinforced Concrete Frame Structures

Abstract

AbstractWhen conducting nonlinear static progressive collapse analysis, dynamic effects caused by sudden column loss are considered by using dynamic increase factors (DIF). The values of the DIF depend both on the characteristics of individual structural elements and on the type of the structure itself. This paper presents the design approach for determining the DIF to consider the contribution of floor slabs to the progressive collapse-resistant ability of reinforced concrete frame structures. A simplified approach is based on the energy conservation principle. In this method, the work done by gravity loads is equal to the strain energy of a structure. Proposed method is validated through a several numerical examples consisting of nonlinear dynamic and nonlinear static analyses of reinforced concrete two-way slab structure. Different column loss scenarios on the first floor are considered to evaluate the DIF values. The comparison of the DIF values obtained according to the proposed method with the values obtained according to American standards is conducted. The results show that the presented approach allows to determine the DIF with sufficient accuracy, and confirm the significant role of floor slabs in the progressive collapse resistance of the whole structure.KeywordsProgressive collapseDynamic increase factorEnergy conservation principleNonlinear static analysisColumn lossTwo-way slab