Modeling and Analysis of Disproportionate Collapse of RC Structures

摘要

Collapse analyses of a 10-story reinforced concrete frame building are carried out to investigate the robustness of structural systems against column removal scenarios. Computationally efficient reduced models are developed and used in the analyses. The building was designed according to the requirements of moderate seismic zones (Seismic Design Category C). Reserve capacity is adopted as a measure of the performance of the building under column removal scenarios. It is calculated as a ratio of applied load to service load (Dead load plus 25 % Live load or 1.0DL + 0.25LL) using static pushdown analysis. Gravity load is proportionally increased until collapse of the building is initiated. Structural system redundancy is examined by checking whether collapse occurs due to the sudden removal of columns under service loading. Comparison between results from two-dimensional (2D) and three-dimensional (3D) analyses indicates the importance of considering the contribution of floor system in disproportionate collapse analysis.