COLLAPSE OF LIGHTLY CONFINED REINFORCED CONCRETE FRAMES DURING EARTHQUAKES

摘要

Post earthquake studies show that the primary cause of reinforced concrete building collapse during earthquakes is the loss of vertical-load-carrying capacity in critical building components leading to cascading vertical collapse, rather than loss of lateral-load capacity. In cast-in-place beam-column frames, the most common cause of collapse is failure of columns, beam-column joints, or both. This study emphasizes failure of columns using data from laboratory studies. Failure models are incorporated in nonlinear dynamic analysis software, enabling complete dynamic simulations of building response including component failure and progression of collapse. This approach enables more realistic simulation of building collapse than is possible using simplified assessment procedures, and provides insight into the conditions that cause collapse and the variability of collapse as a function of input ground motions.