Evaluation of Empirical Joint Shear Strength Models for Simulating Dynamic Responses of Reinforced Concrete Structures

Abstract

The adequacy of a structural system to withstand earthquake-induced seismic forces is largely dependent on how critical components, particularly joints, are considered at the structural design phase. This becomes heavily important in seismic vulnerability and risk assessment of older-type reinforced concrete structures. The purpose of this study is to evaluate two empirical joint shear models derived from two statistical approaches; Bayesian and nonlinear regression by comparing the responses they give with experimental results. A rigid and zero length rotational spring modelling scheme were implemented in the nonlinear finite element platform Opensees. An exterior beam-column joint sub-assemblage was chosen for a reverse cyclic pushover analysis. The results show that the rigid joint model portrays a much stronger joint than is the case, while the rotational spring model is more representative. While both models give data which resembles the experimental data, the nonlinear regression shear capacity model was better for the selected beam-column joint assemblies. The models show discrepancies in predicting drifts at peak loads, suggesting that they are both conservative.