箱型反力墙试验系统结构设计与抗侧刚度分析

Structural design and lateral stiffness analysis of box-type reaction wall test system

以某高校结构实验室反力墙设计为例,介绍了箱型反力墙设计计算过程.通过有限元分析软件ABAQUS建立了反力墙试验系统的整体模型,进行了承载力分析、变形分析及应力分析,验证了设计方案的安全性及合理性.针对目前缺少反力墙抗侧刚度分析的现状,对影响箱型反力墙抗侧刚度的因素进行了有限元分析.结果表明:几何尺寸、混凝土强度、配筋和底部台座刚度是影响反力墙抗侧刚度的主要因素;假定反力墙底座完全固接会夸大反力墙抗侧刚度,反力墙和底座相交处在水平荷载作用下会出现轻微转动,导致墙顶产生不可忽视的位移;预应力筋以及普通钢筋能够提高结构抗侧刚度,使混凝土不出现裂缝,约束混凝土变形,但配筋率增加到一定程度后对反力墙抗侧刚度提升并不明显.

Taking the design of the reaction wall in a structural laboratory of a university as an example,this paper introduces the design and calculation process of the box-type reaction wall.Through the finite element analysis software ABAQUS,the overall model of the reaction wall test system was established,and the bearing capacity analysis,deformation analysis and stress analysis were carried out to verify the safety and rationality of the design scheme.Regarding the lack of lateral stiffness analysis of reaction wall,the factors affecting the lateral stiffness of box reaction wall were analyzed by finite element method.The results show that the geometric size,concrete strength,reinforcement and base stiffness are the main factors affecting the lateral stiffness of the reaction wall.The assumption of complete rigid connection of the reaction wall base will exaggerate the lateral stiffness of the reaction wall,and the intersection of the reaction wall and the test bench will rotate slightly under the horizontal load,leading to the non-negligible displacement at the top of the wall.Pre-stressed reinforcement and ordinary reinforcement can improve the lateral stiffness of the struction,so that the concrete does not crack and is restrained from deformation.However,when the reinforcement ratio increases to a certain degree,the improvement of the lateral stiffness of the reaction wall is not obvious.