Design of RC walls post the Canterbury earthquakes

Abstract

The seismic behaviour of reinforced concrete (RC) walls has received significant attention following the Canterbury earthquakes. The poor performance of RC walls in several modern buildings raised questions regarding the current state of RC wall design and construction practice, as well as the provisions in the Concrete Structures Standard (NZS 3101). Following the earthquakes, both the Canterbury Earthquakes Royal Commission (CERC) and the Structural Engineering Society (SESOC) recommended changes to current design practice and standards to address the identified deficiencies. This paper will explore some of the issues identified by the Canterbury Earthquakes Royal Commission and SESOC, and how these have been addressed in amendment 3 to NZS3101:2006. The amendments have resulted in significant changes to RC wall design provisions related to singly reinforced walls, minimum vertical reinforcement, transverse reinforcement and detailing, axial load limits, and coupled wall systems. For each of these topics, the current state of knowledge, ongoing research, and reasoning behind the new amendments will be discussed