The seismic resistance of unreinforced masonry cantilever walls in low seismicity areas
DOI:
https://doi.org/10.5459/bnzsee.28.3.179-195Abstract
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.
References
Murphy, B.E. and M.G. Stewart. 1993. Analysis of Public Buildings Damaged in the 1989 Newcastle Earthquake, Australian Civil Engineering Transactions, CE35 (3): 187 -201.
Page, A.W. 1992. The Design, Detailing and Construction o f Masonry - The Lessons from the Newcastle Earthquake, Australian Civil Engineering Transactions, CE34 (4):343 - 353.
Standards Association of Australia. 1988. SM Masonry Code AS3700 - 1988.
Lam, N.T.K., J.L. Wilson, G. L. Hutchinson. 1995. Modelling of an unreinforced masonry parapet wall for seismic performance evaluation based on dynamic testing. Department of Civil & Environmental Engineering, University of Melbourne.
Research project funded by Australian Research Council Large Grant, 1994-96. Earthquake Engineering Ground Motions and Structural Ductility Factors for Australian Conditions, by G.L Hutchinson, J.L. Wilson, N.T.K. Lam, G.M. Gibson and V. Wesson.
Brick laying instructor of the Northern Metropolitan Technical College for Advanced and Further Education, Victoria, Australia.
Newmark, M.N. and W.J. Hall. 1982. Earthquake Spectra and Design. Engineering Monograph on Earthquake Criteria, Structural design, and Strong Motion Records, Earthquake Engineering Research Institute, USA.
Priestley, M.J.N. 1985/86. Seismic Behaviour of Unreinforced Masonry Walls, Bulletin of the New Zealand National Society for Earthquake Engineering. 18(2): 191-205 and discussion 19(1): 65-75. DOI: https://doi.org/10.5459/bnzsee.18.2.191-205
Standards Association of Australia. 1993. SM Loading Code Part 4: Earthquake Loads : AS1170.4 - 1993.
Kelly, T.E. 1995. Earthquake Resistance of Unreinforced Masonry Buildings, Proc. 1995 NZNSEE Technical Conference, Rotorua, 28-35.
