Comportement non linéaire des systèmes de murs couplés sous charges sismiques

Abstract

The extensive research effort dedicated to the dynamic behaviour of seismic force resisting systems (SFRS) of multi-storey buildings in recent years has contributed to update the seismic requirements of modern codes and standards worldwide. However, many aspects related mainly to the random nature of ground motions and the complex behavior of concrete structures, in particular in shear at the base of shear walls, are not fully documented. Among these aspects, the study of the effects of higher modes of vibration on the nonlinear dynamic response of shear wall systems during major seismic events was the main impetus motivation for this doctoral research. Its main goal is to contribute, through numerical investigations, to a better understanding of the shear behavior of shear walls systems in Canadian seismic zones. This manuscript-based thesis is based on 5 articles integrated into the body of the document and subdivided into three parts as follows: Part 1, developed around the first and the second paper is dedicated to the linear aspect of this study, namely the analysis and design of shear wall systems commonly used as SFRS of multi-storey buildings located in Canadian seismic zones. The first paper investigates and provides an insight into the main revisions that where incorporated in chapter 4 of National Building Code of Canada and chapter 21 of the Canadian standard Design of concrete structures. It provides an exhaustive state of seismic requirements in effect for this structural system. The second paper discusses the effect of higher modes (of vibration) on the pseudostatic response of shear wall systems. A dynamic amplification factor, specific to that structural system is proposed, that enhances the factors used so far, which are clearly improper as they were derived for other structural systems. Part 2, developed around the third and the fourth paper, deals with the required spectral compatibility requirement of seismic signals used in the step-by-step analysis. An innovative approach, for generating seismic signals compatible with the target spectrum of the code, is presented in the third paper and validated in the fourth paper (conference paper). Part 3, developed in the fifth paper is dedicated to the nonlinear behavior of shear wall systems in Canadian seismic zones. It deals in particular with the dynamic amplification of shear demand due to the inelastic effects of higher modes. A reduction factor for shear is proposed depending on the type of coupling of the shear wall system. The study is based on 480 numerical nonlinear investigations conducted on a wide range (60 specimens) of shear wall systems, designed and detailed according to the seismic requirements in effect in Canada.

Date	17 Oct 2012
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Omar Chaallal (Supervisor)