A study of Structural System Behavior of A seismic Upgraded School Building

• Main Authors: CHEN, JING-TSUN, 陳錦燦
• Other Authors: George C. Yao
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/37841262894399711339

碩士 === 國立成功大學 === 建築(工程)學系 === 85 === Most of the building strengthening programs only think about if the overall strength is adequate to resist a certain acceleration without considering change of member force characteristics induced by the new structural systems. The first purpose of this thesis is to compare member force patterns before and after structural strengthening. An RC school building in Tainan was chosen as the subject of this study. RC shearwall and steel truss were added to the building as strengthening members against earthquake force. Analysis showed that shear and moment in most of the members decreased in the strengthened structure except some of the beams endured larger axial force. Detailed 3D analysis found that beams next to strengthened walls would have to resist large axial force if there''s no attached floor element to share axial force, such as floor beams next to stairwells. If there is no special strengthening strategy to account for this phenomena, premature damage could occur. Low Yield Steel (LYS) is a new product developed to provide lower yielding strength, larger ductility, and still posses the same rigidity as most of the structural steel. The second purpose of this thesis is to investigate the dynamic behavior of structures if LYS is adopted. Dynamic time history analysis is performed to study the performance of LYS truss. Analysis showed that LYS diagonal truss turned to tensile yielding if the compression member buckled. This resulted in plastic deformation of tensile members. In comparison, tensile truss member of the similar structure built with A36 steel still remained in elastic region when compression diagonal buckled. Further analysis of LYS truss of different sizes indicated that smaller dimension LYS truss absorbed more energy. However, beams in the frame experienced more plastic hinges. Therefore, conclusion can be drawn that ductile frames capable of resisting large ductility can choose smaller dimension LYS truss to obtain better energy absorption capability.