两层预制板砖砌体结构房屋模型双向拟动力试验研究

Bi-directional pseudo-dynamic test of a scaled two-story brick masonry building model with precast floor slabs

对一栋缩尺为1∶2的两层单开间预制板砖砌体结构房屋模型进行不同强度地震作用下的双向拟动力试验和非线性地震响应分析,研究该结构在地震作用下的破坏机制、变形、滞回特性及耗能能力等。结果表明:构造柱与圈梁的存在,使得预制板砌体结构具有较好的延性,地震破坏主要集中在底层,即使墙体严重开裂,也不至于整体结构垮塌;双向地震作用下一个方向的承载力与刚度退化会加剧另一个方向承载力与刚度的退化,从而导致砌体结构整体抗震能力的下降;滞回曲线由弓形最后发展到反S形,具有明显的捏缩和滑移效应;建立的砌体结构非线性空间有限元模型,能够反映预制板砌体结构的弹塑性地震响应,计算结果与实测结果基本吻合;两层砌体结构房屋能够满足设计规范的抗震要求。

Bi-directional pseudo-dynamic test and nonlinear seismic response analysis were conducted on a 1 ： 2 scaled two-story brick masonry building model with precast floor slabs under different seismic intensities to investigate its seismic behavior including the failure mechanism, deformation, hysteretic characteristics and energy dissipation, etc. Some important conclusions can be drawn from the testing and analysis and are listed as follows. The existence of constructional columns and ring beams in masonry building with precast floor slabs can effectively resist horizontal earthquake loadings and result in good ductility. The earthquake damage and failure concentrate at the lower story of the two-stor3＇ masonry building. Even if the brick wails are severely cracked, the whole structure may not collapse suddenly. The seismic performance of masonry structure in the horizontal X and Y directions are different. Under the bi- directional earthquake loading, degradation of stiffness and strength in one direction may aggravate to the degradation of stiffness and strength in the other direction, resulting in the overall degradation of seismic performance of masonry building. The hysteresis loops start from the bow shape and become reversed S-shape at the failure stage. The constructed non-linear space finite element （FE） model of brick masonry building can predict the elasto-plastic seismic performance of masonry structures with precast floor slabs. The calculation results from FE simulation are basically consistent with the results from testing. The designed two-story brick masonry building model can meet siesmic requirements of design codes.