||Experimental Study on Seismic Resistance of Indonesian Brick Masonry Houses
Indonesia has suffered severe damages by earthquakes. In particular, human casualty has mainly caused due to collapse of vulnerable brick masonry houses named non-engineered construction. These houses are built by local people who don’t have engineering skill and expertise. Therefore the major aim of this study is improvement of earthquake resistance for the typical brick masonry houses in Indonesia. The present paper describes dynamic seismic performance of Indonesian brick masonry houses with and without reinforcement and material characteristic. The reinforcement method was covering wire mesh which is available in local market and plaster mortar on both sides of walls. Shaking table test of full scale model structure was conducted to clarify seismic performance and assess the effect of reinforcement. Bricks were imported from Jakarta, Indonesia. Both of models survived without visible minor cracks until shaken by 675 gal. Upper west wall of non-reinforced model structure collapsed to out-of-plane direction shaken by 860 gal. On the other hand, reinforced model still survived without any cracks shaken by 2G. As a result of this shaking tests and comparison with past studies, reinforcement using ferrocement was effective to improve earthquake resistant strength of brick masonry structure and suppress deformation particularly out-of-plane wall. Some of shaking table tests of full scale model structures revealed that the dynamic deformability of brick masonry structure was roughly between 1/70 and 1/60 rad, both in-plane and out-of-plane. Natural frequency of out-of-plane vibration of masonry wall was obtained from response acceleration. Both models natural frequency became lower as shaking level was raised although there were no visible damages. It indicated that both models must have gotten invisible damages. The stiffness of non-reinforced wall reduced roughly 10%. It revealed that measuring free vibration of out-of-plane wall is possible to detect invisible damages. Material strength test was conducted to reveal characteristic of local materials and calculate strength of model structures. Bending strength, rigidity, and natural frequency were obtained from the calculation. These results corresponded well with the shaking table test. These results showed that ferrocement layers strengthen bending strength roughly 5 times than original model.
三重大学大学院 工学研究科 博士前期課程 建築学専攻