Analysis of the damage mechanism of a typical RC frame in Wenchuan Earthquake

作者：Lin Xuchuan^*; Pan Peng; Ye Lieping; Lu Xinzheng; Zhao Shichun

来源：China Civil Engineering Journal, 2009, 42(5): 13-20.

• Failure mechanism
• Finite element model
• Floor slab
• Infill wall
• RC frame
• Seismic performance
• Time history analysis

Many RC frame structures were severely damaged with plastic hinges formed at column ends rather than beam ends in the Wenchuan Earthquake, significantly different from the expected failure mode in seismic design code. Based on an investigation of a typical RC frame structure damaged in the earthquake area, time history analyses using a sophisticated finite element method were conducted. Three models were considered, i. e. pure frame, frame with floor slab, and frame with both floor slab and infill wall. A ground motion recorded at the town of Bajiao in the earthquake zone was used for the analyses, and comparison between the three models were carried out to investigate the effect of floor slab and infill wall on the structural base shear, distribution of plastic hinges and failure mechanism. Major findings are: 1, ';Strong column and weak beam'; cannot be guaranteed for the RC frames designed according to the current Chinese design code. 2, Infill walls may significantly alter the failure mechanism of the RC frames. 3, Weak story mechanism may easily occur for structures with non-uniform infill walls. These findings suggest that the effects of floor slab and infill wall should be considered in seismic design, the stiffness and strength of columns need be enhanced to achieve ';strong column and weak beam'; behavior, and structural elasto-plastic analysis model should take slabs and infill walls into account.

• 出版日期2009
• 单位西南交通大学; 清华大学