Experimental assessment of in-plane behavior of traditional Tibetan three-leaf walls

Multi-leaf masonry is a technique that can be dated back many centuries, but limited reports can be found on the seismic behaviors of three-leaf walls (TLWs). This study intended to understand better the seismic capacity of traditional Tibetan three-leaf walls (TTTLWs) constructed with stones and mud mortar by an in-plane cyclic shear loading test. A series of test results, including failure modes, hysteretic behavior, ductility, stiffness degradation, energy dissipation, and in-plane and out-of-plane bulge of tested walls were analyzed and discussed. And the experimental values of the shear strength and shear modulus were compared with the predicted values given by prediction models available in literature. Three types of failure modes were found on the wall specimens in this test: sliding of mortar joints, cracking of block stone at wall toe, and separation between external and inner leaves. The TTTLWs may be concluded to have a low shear strength of 0.118–0.162 MPa and medium shear modulus of 99–147 MPa compared with the published data of multi-leaf stone masonry. The shear strength of TTTLWs is controlled by the flexural failure, and can be predicted by the formulas recommended by ASCE.