Turkish Journal of Engineering and Environmental Sciences

Abstract: The typical housing type of the rural population of Turkey is load-bearing masonry units. Masonry buildings are as vulnerable to seismic failure as reinforced concrete buildings. However, the majority of research efforts are directed towards reinforced concrete buildings. Masonry walls that constitute masonry structures are subject to in-plane and out-of-plane seismic forces during an earthquake. It is shown in this paper that out-of-plane acceleration can exceed in-plane accelerations. Therefore, it is very possible that masonry buildings begin to fail by collapse of upper story walls subject to out-of-plane accelerations. My masonry wall loaded out-of-plane fails by forming fracture lines similar to the yield lines of a 2 way reinforced concrete slab. Of course, the failure of the masonry wall is brittle. The fracture lines of a masonry wall loaded out-of-plane form rather quickly and the applied load is reduced. As such, the masonry wall loaded out-of-plane does not seem to have enough ductility to justify the use of a seismic force reduction factor of R_a(T₁) = 2.5 as specified by the Turkish Earthquake Code.

Key Words: Masonry structure, Out of plane loading, Seismic accelerations