Assessing the validity of rocking in URM perforated shear walls

Abstract

The validity of implementing a ‘rocking wall retrofit’ for New Zealand’s earthquake prone unreinforced masonry buildings was assessed. The parameters governing rocking response are detailed, and the identification of rocking-sympathetic characteristics in representative New Zealand unreinforced masonry building typologies are highlighted. A series of experimental tests were conducted in order to identify variables that had potential to alter the rocking response of piers subjected to seismic loading. The influence of boundary conditions on the failure mechanism of unreinforced masonry piers is discussed in relation to the design of the full scale testing rig. Results from testing of two full scale unreinforced masonry sub-structures consisting of two piers coupled by a deep spandrel are reported. The tests access the influence of aspect ratio and vertical precompression levels on the forcedisplacement and pier-spandrel rotational behaviour. Crack patterns evidenced in a series of plaster formed scale models is compared to those developed during full scale pseudo-static cyclic tests on unreinforced masonry shear walls of the same geometry.