The ductility of structural walls

T Paulay,W J Goodsir

doi:10.5459/bnzsee.18.3.250-269

Abstract

The behaviour of four approximately 1/4 full size reinforced concrete structural wall models, subjected to cyclic lateral shear load and variable axial compression, is reported. The primary aim of the study was to investigate the mechanism of out of plane instability and the adequacy of existing code provisions with respect to the confinement of critical parts of the flexural compression zones of wall sections that may be subjected during an earthquake to large inelastic displacements. While all units exhibited good energy dissipation properties, failure in the majority of cases occurred suddenly when concrete compression strains resulting from large ductility demands became excessive in the unconfined regions of the wall section. Failure by out of plane buckling was found to occur at a relatively small lateral load, after the buckled region has been subjected in a proceeding cycle to very large inelastic tensile strains. Recommendations are made for improved arrangement of the confining hoop reinforcement in the end regions of wall sections.

Highlights

The potential for both lateral load resistance and drift control of walls in reinforced multistorey buildings has long been recognised
Relevant early building code provisions (1) werebased on assumptions that structural walls which may be subjected to large earthquakes, will possess only limited ductility
Subsequent experimental work (2,3,4,5) and theoretical considerations (6,7) have shown, that with appropriate detailing of the wall reinforcement and the application of capacity design principles (8), large displacement ductilities combined with excellent energy dissipation may be achieved

Summary

Introduction

The potential for both lateral load resistance and drift control of walls in reinforced multistorey buildings has long been recognised. Relevant early building code provisions (1) werebased on assumptions that structural walls which may be subjected to large earthquakes, will possess only limited ductility. Subsequent experimental work (2,3,4,5) and theoretical considerations (6,7) have shown, that with appropriate detailing of the wall reinforcement and the application of capacity design principles (8), large displacement ductilities combined with excellent energy dissipation may be achieved. The existing provisions of N Z S 3 1 0 1 : 1 9 8 2 (8) arebased in this latter premise. A reduced lateral load resistance in multistorey buildings with ductile structural walls, comparable to that of buildings with ductile frames only, could be accepted (9)

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