Nonlinear modeling and analysis of reinforced concrete structural walls

Abstract

The severe damage and collapse of many reinforced concrete (RC) wall buildings observed in recent earthquakes in Chile (2010) and New Zealand (2011) showed that RC walls did not perform as required by the building codes of both countries. In this context, it is necessary to intensify the research efforts towards more precise simulations of damage indicators, particularly of local engineering demand parameters, such as material strains, which are fundamental for the application of the Performance-Based Earthquake Engineering (PBEE) methodology. The main goal of this study is to propose an analytical nonlinear model capable of simulating the response of isolated reinforced concrete walls at a global and local level. This work compared different response parameters obtained from nonlinear analysis of RC walls subjected to cyclic loads, using finite element models developed with DIANA software. The modeling approach was validated with experimental data from two RC walls. A sensitivity analysis of the seismic response parameters to uncertain modeling variables such as the compressive fracture energy of unconfined and confined concrete, among others, was also performed. The analytical models adequately captured the lateral force-displacement relationship, stiffness degradation, and the profile of vertical strains at the base of the walls for different levels of demand. The sensitivity analysis showed that the dispersion of the local response is greater than the dispersion in the global response when considering different modeling parameters. Dispersion increases as the level of demand increases.

Manuscript received: October 7, 2021
Manuscript accepted: November 18, 2021