多因素作用下承重墙刚度退化伪静力试验研究

为研究砂浆强度、开洞率和高宽比3个因素对砌体承重墙刚度退化的影响,以3层砌体房屋的底层承重墙为原型,设计4片1∶2的缩尺试件进行伪静力试验。试验结果表明:在加载初期,各因素影响类似,刚度退化均较快;试件开裂后,刚度退化均放缓,各试件在开裂、极限和破坏等特征点的刚度退化系数在76%、20%和16%左右。砂浆强度愈低,砂浆粘结性能较差,试件初始刚度愈小,开裂后刚度退化稍缓,试件塑性变形小。开洞率愈大,初始刚度愈小,开裂后刚度退化加剧,试件塑性变形最小。高宽比愈大,初始刚度愈小,开裂后刚度退化幅度最小。研究成果可为深入探讨各因素对砌体墙刚度退化的研究提供参考。

Study on pseudo static test of stiffnessdegeneration of bearing wallunder role of multi factors

To study the effect of three aspects such asmortar strength, of opening rate and ratio of height and width on thestiffness degradationof masonry bearing walls,the paper took the bottom walls of a 3-story masonry structure as prototype,and designed four scaled wall specimens to carry out pseudo static test.The results show that the stiffness degenerates quicklyat the preliminary stage of loading. The influence of every factor is similar.The stiffness degradation slows downafter cracking of test-piece.Thecoefficient stiffness degradation at some feature points such as crack load, ultimate load and failure load is respectively about 76%, 20% and 16%. The lower the mortar strength,the poorer the viscidity of mortar.Thelessthe initial stiffness,the slower the stiffness degradates after cracking,theplastic deformationof test-piece is small. The lager ratio of openings, the smaller initial stiffness.thestiffness degradation intensify after cracking.The plastic deformation is the minimum. The larger the ratio of height and width, the less the initial stiffness,the stiffness degradation is the minimum. Theresult can provide reference for further research of effect of every factor on stiffness degeneration of masonry wall.