Abstract
The time-history analysis method, the response spectrum method and the equal energy method are considered in this paper to determine the seismic resistance of unreinforced masonry (URM) cantilever walls. Fundamental problems with each of the methods in predicting the response of a simple cantilever wall model to the El Centro earthquake have been identified The response spectrum method underestimated the true seismic resistance of the wall by a factor of more than 2.0, whilst the equal energy method could overestimate the resistance of the wall by up to 3.5 times depending on the natural frequency adopted. Difficulties with establishing realistic dynamic properties of brickwalls are highlighted. A probabilistic procedure involving the analysis of a large number of representative ground motions and cantilever wall models is recommended for future investigations to derive reliable and simple expressions to predict the response of cantilever masonry walls.
Highlights
Domestic unreinforced masonry (URM) construction in most parts of Australia, like other countries with low seismicity, have not been designed for earthquake loadings
This paper examines various methods which can be applied to determine the out-of-plane seismic resistance of URM cantilever walls using a simple 1. 0 m high wall model and the El Centro record for illustration
A comparison of the results obtained from the equal energy method using two alternative ways (Alternatives I,11) for defining the natural frequency of the wall is made with the results from the time history analyses
Summary
Domestic unreinforced masonry (URM) construction in most parts of Australia, like other countries with low seismicity, have not been designed for earthquake loadings. The mortar bond strength at the base of the walls is questionable due to uncertainty in the mortar strength, the presence of damp-proof courses and the effect of thermal stress cycles. For these reasons, the Australian Masonry Standard AS3700 [3] specifies zero tensile strength for free standing cantilever walls subjected to lateral load. The Australian Earthquake Loading Standard AS 1170.4-1993 uses a model response spectrum for stiff soil based on Californian interplate earthquake events and the El Centro ground motion recorded in the north-south direction during the 1940 earthquake at Imperial Valley in Southern California. The El Centro record has been selected for analyses to demonstrate both the response spectrum approach and the equal energy approach
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
