The influence of axial load variation on the seismic performance of rc buildings

Abstract

It is well known that the axial load can largely vary during a seismic event, playing an important role in the seismic performance of RC columns. In existing buildings this problem can be even more significant than in new ones, since the material can easily present poor mechanical properties. The paper is aimed at investigating the role of the axial load variation on the seismic capacity of RC columns, evaluated in terms of limit chord rotation and shear force, according to Eurocode 8. The research is performed with reference to a case-study, which is a doubly symmetric 4-storey RC framed building. The axial load variation affects both the seismic response and the capacity of the columns of the case-study, and, therefore, their seismic performance. Special attention has been paid to the role of the effective concrete strength of columns on the sensitivity of the seismic performance to the axial load variation.