填充墙外廊式RC框架结构倒塌振动台试验研究

为研究外廊式RC框架结构体系中填充墙对结构抗地震倒塌性能的影响，以汶川地震中倒塌的漩口中学教学楼为原型，进行了一个缩尺比例为1∶4的外廊式框架结构模型振动台试验，得到了结构地震倒塌的全过程现象和破坏倒塌机制。试验结果表明：模型结构在振动台上的倒塌始于结构底层教室侧纵向框架柱的破坏，该侧框架柱破坏位置集中在柱端和半高填充墙位置处，形成明显塑性铰；之后，纵向另外两榀框架柱相继失效，造成结构底层率先倒塌，继而产生更大范围的逐层连续倒塌，与实际震害的倒塌模式基本一致。进一步利用ABAQUS有限元软件，建立了有无填充墙外廊式框架结构的数值模型，进行了底层柱剪力和塑性铰分布情况分析，结果表明，半高填充墙对柱的约束效应对结构损伤分布和破坏机制产生较大影响，建议在设计中应考虑填充墙的刚度，避免半高填充墙与柱的硬连接布置。

Shaking table collapse test on exterior corridor RC frame with infill walls

One 1/4 scaled specimen, whose prototype structure is a teaching building in Xuankou Middle School that collapsed under the Wenchuan earthquake, was tested on the shaking table to study the influence of infilled walls on the seismic collapse resistance of the exterior corridor RC frame. The complete collapse process and failure mechanism of the test model were obtained and studied. In the process of collapse, the bottom columns on the side of the classroom are damaged at first. The local damage to columns is focused at the top and the half-height of infill walls and the plastic hinge is obviously formed. When the bottom columns on the side of the classroom lose their vertical load-carrying capacity, the remaining columns fail subsequently. The bottom story of the frame collapses completely, resulting in a wide range of story-by-story collapse, which is consistent with the seismic damage investigation results. Subsequently, two numerical models of the exterior corridor RC frame with and without infill walls were established by ABAQUS. The distribution and development of shear force of bottom columns and plastic hinges were analyzed, which reveal that the restraint effect of half-height infill walls on the columns has a great influence on the structural damage mechanism. And the design suggestions for considering the lateral stiffness of infill walls and avoiding rigid connection between half-height infill walls and columns are also recommended.