Cyclic loading tests of two model frames simulating modern street buildings with stairwell wallsstreet buildings with stairwell walls

• Main Authors: Chen-Yu Wu, 吳鎮宇
• Other Authors: Hung-Jen Lee
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/22721446047504938857

碩士 === 國立雲林科技大學 === 營建工程系碩士班 === 99 === According to 921 earthquake reconnaissance, low-rise RC street buildings showed serious collapse because of the effect of soft story mechanism at ground floor. However, many street buildings remained safe due to the existence of one or two staircase walls which were parallel the street roads. This study, commissioned by the Architecture and Building Research Institute, Ministry of the Interior, investigated the earthquake resistance capacity of common 2-story frame structure of low-rise RC build street building system under the influence of the stairwell wall case by reversal cyclic testing of two specimens. Two two-story by two-bay RC frames (scale 4/5) with different partial infill walls were designed and constructed to simulate an interior frame aside the stairwell of a street building. Cyclic loading tests were carried out to study their failure mechanism and seismic performance in the laboratory of Architecture and Building Research Institute, Ministry of the Interior. Test results showed that although the first specimen, with stairwell wall infilled three-fourths beam span, had larger initial strength and stiffness, but its strength declined rapidly after the maximum strength as roof drift ratio greater than 0.75%. It showed a typical shear controlled behavior. When the roof drift ratio reached 1.5%, both the horizontal wall section and the beam section appeared shear failure and the strength of the whole structure rapidly diminished. The second specimen, with stairwell wall infilled half beam span, had lower initial strength and stiffness, but it had better toughness. Even the ends of beams yield, the specimen can maintain its lateral carrying capacity after the roof drift ratio greater than 0.75%. When roof drift ratio reached 1.5%, the specimen reached its maximum strength. It showed a typical flexure controlled behavior. This study elaborates the observation of reversed cyclic load test, including hysteresis cycle, energy dissipation, crack propagation and the failure mode, and further attempts different simulation skills of the pushover analysis model with regards to the wall horizontal section as well as the beam section. The effort has been made that the results of pushover analysis can match the test results better than before. The test results and analysis method can be used for reference for engineers in designing the new street buildings and assessing the existed street buildings.