拆除窗下墙对砌体墙抗震性能影响的试验研究

Experimental research on seismic performance influence of masonry wall removed spandrel wall

多层砌体结构底层窗下墙被拆除的情况较为普遍,拆除窗下墙会造成砌体墙抗震能力降低,增加地震时拆改结构破坏的风险。为了解拆除窗下墙对砌体墙抗震性能的影响,进行了5片足尺砌体墙的低周反复荷载试验,获得了原型砌体墙试件、拆除两侧窗下墙试件、拆除一侧窗下墙试件的主要破坏过程及破坏形态,对比分析了各片墙体的承载力、变形及抗侧刚度等抗震性能的差异。试验研究表明:拆除窗下墙后砌体墙高宽比变大,水平荷载作用下转动变形在总变形中所占比重增加,破坏形态可由水平剪切破坏向斜压破坏、竖向剪切破坏等其他破坏形式转变;拆除两侧窗下墙的试件其承载力、抗侧刚度较原型砌体墙试件的有较大幅度降低;拆除一侧窗下墙的试件其未拆除侧的承载力、抗侧刚度与原型砌体墙试件的基本相同,拆除侧的则较原型砌体墙试件的有较大幅度降低。研究结果为进一步研究拆除窗下墙对砌体结构整体抗震性能的影响提供了试验数据。

Removing the spandrel wall will decrease the seismic capacity of masonry wall,and increase the failure risk of the structure under earthquake. In order to investigate the influence of removing the spandrel wall on the seismic performance of masonry wall,the low cyclic reversed loading tests of five full scale masonry walls were performed. The main failure process and failure mode of the walls were introduced and the seismic performance including bearing capacity,deformation and lateral stiffness were analyzed. Test results show that: the height to width ratio of the wall with spandrel wall removed becomes larger; the rotational deformation in the total deformation proportion increases,and the failure pattern may be changed from horizontal shear failure to other different forms. The bearing capacity and lateral stiffness of the walls with both side of spandrel walls removed are lower than those of prototype wall to a certain extent. The seismic behavior of the specimens with dismantled one side is basically the same as that of prototype wall.The results provide test data and reference for the further study about the overall seismic performance of the masonry structure removing spandrel wall.