Numerical Investigation of Progressive Collapse Resistance for Seismically Designed RC Buildings

摘要

In this paper the progressive collapse behavior of a reinforced concrete framed building located in different seismic areas from Romania is investigated. The six-storey structure is designed for low (ag = 0.08 g), moderate (ag = 0.16 g) and high (ag = 0.24 g) seismic zone. Based on the GSA (2003) criteria, a nonlinear static analysis is conducted first in order to estimate the progressive collapse resistance of the models. It was shown that all the structures will collapse when subjected to interior column removal. A nonlinear dynamic analysis is performed to validate these results; it was demonstrated that the capacity curves obtained with the nonlinear static procedure fail to predict the progressive collapse resistance of the analysed models because the dynamic increase factor (DIF) of 2.0 recommended by the GSA (2003) Guidelines seems to be overestimated. A nonlinear incremental dynamic analysis is carried out in order to estimate with maximum accuracy the ultimate load bearing capacity to progressive collapse of the structures under investigation. The variation of DIF with respect to the level of loading is determined. The influence of the seismic design on the progressive collapse resistance of the analysed models is quantified as well.