Development of a Novel V-D Strut Model for Seismic Analysis of Confined Masonry Buildings

Abstract

Confined masonry (CM) offers an affordable and seismically safe building typology, which is already a widespread construction technique in several seismically-prone countries, and is currently evolving as a popular construction technique in many other countries. This building system has shown phenomenal performance in the past seismic events; however, its engineering behavior has not been established sufficiently due to significant variation in materials used and lack of research in understanding the complex composite behavior under different loading conditions. Significant gaps exist in research, especially in reliable methods of seismic analysis and design; consequently, modeling a CM building still fails to be a persuasive choice. The primary objective of this study is to develop a simple generalized numerical model that can reliably predict the nonlinear behavior of CM walls under seismic loads. A comparative numerical study was first carried out to assess a suitable model for CM walls based on the realistic simulation of axial forces in tie-columns and tie-beam deflection under the action of gravity loads. A new macro-model “V-D strut model” was finally developed for the analysis of CM walls under the action of both gravity and seismic loads. Due care was taken to simulate not only the initial stiffness and strength of CM walls but also to characterize their failure modes in a simplified way using an effective shear strength of masonry estimated by carrying out a parametric finite element study. The effectiveness of the V-D strut model was validated by an accurate prediction of the lateral load response of several CM walls tested previously.