Out-of-Plane Seismic Behavior of Unreinforced Masonry Infilled Walls in RC Frames

• Main Authors: Hsuan-Pai Lin, 林宣百
• Other Authors: Yi-Hsuan Tu
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/07475701989160419135

碩士 === 國立成功大學 === 建築學系碩博士班 === 94 === In Taiwan, many people live in RC buildings that were constructed with un-reinfroced infilled masonry walls in RC frames. The existing seismic assessment for such structures usually emphasizes only on in-plane capacity of the infilled walls. However, the damage reports for earthquakes tell that sometimes the infilled masonry walls collapse at out-of-plane direction before they can contribute in-plane capacity. In this thesis, failing behavior of infilled masonry walls and interaction between the walls and RC boundary frames when they were subjected to out-of-plane loading were investigated from results of in-site tests. Analytical models were developed for estimating out-of-plane cracking and ultimate strength and displacement of the infilled masonry walls. From 2 in-site tests, it is found that when the infilled masonry walls were subjected to out-of-plane concentrated loading, the top and bottom of walls bended and cracks happened at the tensile side. Out-of-plane displacement measured show that after the cracking happened, region between top and bottom cracks remained rigid, therefore the walls behave like 2-force members with hinges at both ends. The analytical model assumes that infilled masonry walls are subjected to only concentrated loading. The cracking strength and displacement can be calculated simply by material and geometric properties, while the ultimate strength and displacement are developed by strut model. The ratio of height to thickness and compressive strength of brick piers are found to be main factors of the out-of-plane ultimate strength. Analytical P-Δ curves of infilled masonry walls are compared with the experimental ones. Analytical model presented in this thesis shows conservative but better prediction than other analytical models. It shows that the analytical model presented in this thesis is reasonable and applicable.