In-plane biaxial loading on a masonry wall : an investigation of the ultimate strength of masonry under in-plane biaxial loading

Abstract

The ultimate strength of masonry under in-plane biaxial compression was investigated, by testing one-third scale masorny panels. In order to be able to define failure under such a loading condition, a three dimensional failure surface in terms of ov, oH and 0 is required. ov and oH are the applied stresses and 0 is the rotation of the bedjoint with respect to one of the principal loading axes. The main variables in the testing programme were the precompressive stress oH and the bed joint orientation 0. The bed joint orientation was varied at intervals of 45° whilst the precompressive stress was determined from the uniaxial strength of the masonry panels. In order to test these masonry panels a reaction frame and testing rig were designed, commissioned and manufactured. Although the accuracy of the results obtained cannot be determined, there is a clear indication that local masonry does exhibit substantial increase in strength under in-plane biaxial compression. The failure surface for the bed joint orientations tested was also attempted, but there are too few points to be able to make any conclusions.