基于Push-over的农村砌体房屋地震响应分析

[目的] 农村砌体房屋是震害受损最普遍的结构形式,通过分析砌体结构地震响应特征及评估砌体结构抗震水平,减小地震作用下引发的房屋坍塌等次生灾害,降低震害损失。[方法] 运用ABAQUS分析软件建立农村砌体房屋三维有限元分析模型,基于Push-over分析方法得出地震作用下结构损伤、裂缝分布以及荷载位移曲线等地震响应特征,以层间位移角为量化指标对抗震性能进行评估。[结果] 研究发现:地震作用下结构开洞纵墙损伤大于未开洞横墙,底层损伤大于上层;裂缝主要集中在楼梯间、大开间墙体等应力集中处以及构件连接薄弱处;最大层间位移角出现在开洞纵墙底层墙体,结构承重横墙稳定性较开洞纵墙好。对于不同模型,砂浆强度等级由M7.5提升为M10时,结构损伤度下降2.1%,基本设防和罕见地震下结构最大层间位移角分别减小24.2%和30.5%;设置圈梁构造措施后,结构损伤度下降10.9%,基本设防和罕见地震下结构最大层间位移角分别减小30.0%和45.1%;提高砂浆强度等级并设置圈梁构造措施时,结构损伤度下降17.4%,基本设防和罕见地震下结构最大层间位移角分别减小45.7%和63.2%。[结论] 提升结构砂浆强度等级并设置圈梁构造措施后,砌体房屋稳定性满足抗震要求,对提高砌体结构抗震性能作用显著。
[Objectives] Rural masonry building is the most common form of earthquake damaged structures. Analysis is conducted on the seismic response characteristics of masonry structure and evaluating anti-earthquake level of masonry structure,to reduce the secondly-disaster such as house collapse induced by earthquake and seismic damage loss. [Methods] In this paper,a three-dimensional finite element model of masonry structure was established by ABAQUS analysis software,and the seismic response of structural damage,crack distribution and load displacement curve under the earthquake were obtained based on Push-over analysis method. Then the seismic performance of the structure was evaluated based on the inter story displacement. [Results] The injury of longitudinal wall with holes was greater than the cross wall without hole;the underlying structure damage was greater than the upper,and cracks were mainly concentrated in the stairwell and the walls with the stress concentration under the earthquake. When the mortar strength grade was increased from M7.5 to M10,the degree of structural damage decreased by 2.1%;the maximum inter story displacement angle under the basic design and rare earthquake decreased by 24.2% and 30.5%. When the beam was set up,the degree of structural damage decreased by 10.9%;the maximum inter story displacement angle under the basic design and rare earthquake decreased by 30.0% and 45.1%. When the structure of mortar strength grade was increased and the beam was set up,the structural damage degree decreased 17.4%,and the maximum inter story displacement angle under the basic design and rare earthquake decreased by 45.7% and 63.2%. [Conclusions] When the structure of mortar strength grade was increased and the beam was set up,the stability of masonry structure can meet the seismic requirements. It is significant to improving the seismic capacity of masonry structure by lifting the strength mortar grade and setting the ring beam