砌体墙抗震性能伪静力试验研究

考虑了砂浆强度等级、开洞率和高宽比3种因素,对3层砌体房屋的底层墙进行抗震性能的伪静力试验.分析了破坏形态、滞回耗能、抗震承载力、刚度退化和墙体侧移情况.结果表明,砂浆强度等级和高宽比对破坏形态的影响类似,而开洞率稍有不同;砂浆强度等级愈低、开洞率愈大或高宽比愈大时,墙体的耗能能力及抗震承载力愈小,其中开洞率的影响更为显著.开裂前,各因素下刚度退化均较快,且趋势一致;开裂后,开洞率大的试件刚度退化最快;达到极限荷载时,各因素下的刚度退化较大,为初始刚度的20%左右.开裂后,开洞率大的墙肢薄弱,墙高方向的侧移分布曲线明显外凸.

Pseudo-Static Tests on the Seismic Performances of Masonry Walls

Considering the factors such as mortar strength,ratio of openings and aspect ratio,Psudo-static tests on the seismic performances of the bottom walls of a 3-story masonry structure were conducted.The damage models,hysteretic properties,aseismic capacities,stiffness degradations and lateral displacements of walls were analyzed.The results show the damage models are significantly influenced by the ratio of openings,and not obviously affected by the mortar strength or aspect ratio.The hysteretic properties and aseismic capacities are unfavorable under lower mortar strength,larger ratio of openings and larger aspect ratio.The ratio of openings significantly affects the aseismic capacity.Before cracking,the influence of each factor on the speed of stiffness degradation is almost the same and the degradation is rather fast.While after cracking,the ratio of openings is the most prominent factor and the specimens with larger ration of openings degradate faster.The residual stiffness is about 20% of the initial stiffness when the specimens reach their limit load state.The distribution of lateral displacement of the specimens with lager ratio of openings exhibits an outer convex curve after cracking.