Seismic behaviour of confined masonry walls

The results of tests of plain and confined masonry walls with hll ratio equal to 1.5, made at 1:5 scale, have been used to develop a rational method for modelling the seismic behaviour of confined masonry walls. A trilinear model of lateral resistance-displacement envelope curve has been proposed, where the resistance is calculated as a combination of the shear resistance of the plain masonry wall panel and dowel effect of the tie-columns' reinforcement. Lateral stiffness, however, is modelled as a function of the initial effective stiffness and damage, occurring to the panel at characteristic limit states. Good correlation between the predicted and experimental envelopes has been obtained in the particular case studied. The method has been also verified for the case of prototype confined masonry walls with hll ratio equal to 1.0. Good correlation between the predicted and experimental values of lateral resistance indicates the general validity of the proposed method. (C) 1997 John Wiley & Sons, Ltd.