Book Description

Building structures using masonry is one of the most widely adopted construction practices. However, its seismic performance in earthquake prone regions is a major concern. Majority of the research work which has been carried out for studying the failure pattern of masonry, either targets in-plane failure or out-of-plane failure of walls. However, various survey reports on the damage caused by earthquakes mention about failure of the corner walls of masonry structures such as those situated at the end of a row of structures, in a peculiar manner. Failure in such walls is characterized by the simultaneous overturning of a portion of orthogonal walls which is possible only if lateral loads act along the corners, implying each corner wall is subjected to bidirectional loading. Since the literature addressing such failure, are limited, therefore this study has been carried out to explore the reasons leading to corner failure of masonry structures.In this study, in order to examine the failure pattern at corner in dry masonry structures, finite element (FE) technique was adopted. Various masonry models with varying vertical load were subjected to dynamic loading along the corner to observe their combined effect on failure pattern. This analysis showed the pattern of propagation of crack through the bed joint along under varying dead load conditions. Since it is not possible to perform FE analysis for all the masonry structures, mathematical relations were derived to calculate the limiting acceleration at which corner failure can occur. These relations were obtained by assuming feasible failure mechanisms and applying the concept of limit state analysis. For studying the failure pattern of corner in mortar bonded masonry, the FE approach adopted for dry masonry was extended. Micro-modelling which is mostly adopted for modelling mortar bonded masonry was modified by introducing the concept of equivalent friction to simulate the behaviour of mortar in shear. Cracks were observed to pass through the bricks along with the bed joints which lead to toe crushing due to overturning of failure portion. Through this study an understanding of failure of the corner has been developed.