底层窗间墙破坏模式砌体抗震性能试验研究

Experimental research on seismic behavior of masonry structure subjected to failure of bottom piers between windows

为研究整体开洞墙体中发生底层窗间墙破坏模式时墙体的抗震性能,对一砌体结构缩尺开洞墙体模型展开多点同步加载拟静力试验。分析了各层墙体与整片墙的破坏特征、承载与变形能力、滞回耗能特性、刚度退化规律及延性表现,重点研究了底层窗间墙位于整体结构中时其破坏过程与变形规律。试验结果表明:破坏模式相同的开洞墙体较单独墙肢抗震性能有所不同,各工况加载峰值点的上升与下降过程更为缓慢、滞回曲线更为饱满、刚度退化过程更为缓和以及延性特征更为明显。基于底层窗间墙破坏模式,依据现行规范中开洞墙体承载力计算方法所得结果与试验结果吻合,但强弱构件失效机制无从体现。试验结果可为探求砌体结构合理设计方法与实现开洞墙体延性破坏模式提供依据。

A multi-point loading reduced-scale pseudo-static test was carried out to study the seismic performance of the masonry wall with uniformly distributed openings, particularly the failure mechanism of the bottom wall piers between windows. The failure pattern, strength, deformation capacity, hysteretic energy dissipation behavior, stiffness deterioration and ductility were investigated. A special examination was given to the failure process and deformation mode of the bottom wall piers between the windows. The test results indicate that the masonry wall piers, with the same failure pattern as the single wall, present different seismic performance, for instance, the slower rise and fall at the peak load, fatter hysteresis curve, less stiffness degradation and better ductility. Based on the failure pattern of the bottom wall pier, the current calculation methods on the bearing capacity of the wall with openings coincide with the test results, but fail to realize the failure pattern with the combined weak and strong structural components. The experimental study provides the reference to realize a more reasonable design method and ductile failure pattern of the masonry structure.