SANADA, YASUSHI1; YULIA, HAYATI2; TOMONAGA, TAKUYA3; KANADA, TAKAFUMI4

1) Associate Professor, Osaka University, Division of Global Architecture, sanada@arch.eng.osaka-u.ac.jp

2) Graduate Student, Toyohashi University of Technology, Department of Architecture and Civil Engineering, yulia_71@yahoo.com

3) Former Graduate Student, Toyohashi University of Technology, Department of Architecture and Civil Engineering

4) Technical Associate, Toyohashi University of Technology, Department of Architecture and Civil Engineering

One of the most critical deficiencies of unreinforced masonry (URM) walls is the out-of-plane brittleness. This study proposes a new retrofit technique for improving the seismic performance of masonry walls in the out-of-plane direction. Geometrical axial elongation of masonry walls under lateral deformation is closely studied and utilized as a source of passive compression in the proposed method. Applying tension rods to masonry walls to restrain the axial elongation, compression can be applied to wall cross-sections under lateral deformation and therefore increases the flexural strengths. Application tests were conducted using brick wall specimens in Indonesia. The strengthened/un-strengthened specimens by the proposed method were subjected to static uniform out-of-plane loads. Consequently, the proposed retrofit improved the out-of-plane performance, namely deformation capacity as well as flexural strength of the brick wall specimens. Moreover, a theoretical method is presented to evaluate the seismic performance of masonry walls strengthened by the proposed method.

Keywords: Brick masonry, deformation capacity, flexural strength, seismic retrofit, structural test