Seismic fragility of non-ductile and limited ductile reinforced concrete shear walls under in-plane loading conditions

Abstract

Seismic fragility functions for non-ductile and limited ductile RC walls under in-plane loading scenarios are presented in this paper. In the absence of comprehensive experimental studies, a hybrid approach was adopted, in which the experimental data available from the literature and numerical data generated in this study were combined to establish the fragility functions. An experimental database was developed for non-ductile (with single layer of reinforcement) and limited ductile walls (double layer of reinforcement). Gaps in the RC wall datasets were identified in terms of missing aspect, slenderness and compression stress ratios for various concrete strengths, which were then analysed through a numerical approach. A macro element modelling concept of analysing RC wall was developed by incorporating plastic-hinge formation, compression crushing, shear failure, bond slip and bar rupture as they are the common failure characteristics of non-ductile and limited ductile walls. Three sets of damage states were defined according to the failure sequence that corresponded to the in-plane load-displacement responses of the analysed RC walls. The established fragility functions revealed that the non-ductile RC walls are more vulnerable under in-plane loading than the limited ductile RC walls. In general, the probability of exceedance to ultimate damage state was about 57 to 77% higher in the non-ductile walls than limited ductile walls. The fragility functions established through this study can be used for vulnerability and loss assessments of buildings comprised of these RC walling systems.