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

It is well known that the axial load plays an important role in the eval-uation of the structural capacity of RC columns. In existing buildings this problem can be even more relevant than in new ones, since the material can easily present poor mechanical properties. The paper is aimed at investigating the role of the axi-al load variation on the seismic capacity of RC columns, evaluated in terms of limit chord rotation. The study is performed with reference to an RC building case-study, which is a doubly symmetric 4-storey RC building. The axial load var-iation affects both the seismic response and capacity of the case-study, and, there-fore, its seismic performance. Special attention has been paid to the role of the ef-fective concrete strength of columns on the sensitivity of the seismic performance to the axial load variation.