X型中心钢支撑混凝土框架地震反应特性

Seismic response properties of steel concentric X-centrically steel braced RC frames

为了研究X型中心钢支撑钢筋混凝土框架结构体系地震反应特性,分别对5层、8层和12层钢筋混凝土框架和X型中心钢支撑钢筋混凝土框架模型结构的动力特性和弹性地震反应进行分析,探讨X型中心钢支撑对结构侧移刚度、自振周期、水平地震作用下结构内力分布的影响。研究结果表明:在没有明显增大结构重力荷载的条件下,支撑提高了结构侧移刚度,降低了结构自振周期,减小了水平地震作用下结构侧移和层间侧移角;支撑分担了部分楼层剪力,改变了结构的内力分布特点,降低了结构构件的内力,为实现"多道设防"的抗震设计原则创造了有利条件;X型中心钢支撑对钢筋混凝土框架结构地震反应的影响随着层数的增大而有所降低,与普通框架相比,5层、8层和12层支撑框架最大层间位移角的降低幅度分别为36%,24%和20%。

In order to study the seismic response properties of steel concentric X-centrically steel braced RC frames（RC-XCSB frames）,the structural models of RC frames and RC-XSCB frames of 5-storey,8-storey and 12-storey were analyzed, and the influences of steel concentric X-centrically steel braces on the dynamic characteristics and elastic seismic responses of RC frames such as the lateral stiffness, the natural period and internal force distributions under horizontal earthquake action of structures were investigated. The results show that the structural lateral stiffness increases, the natural period decreases, and the storey displacement and inter-storey drift ratio under horizontal earthquake action decreases, although the representative values of structural gravity load can not be increased significantly because the steel concentric X-centrically steel bracings are arranged in RC frames. For the part of storey shear force to be shared by concentric X-centrically steel braces, the internal force distribution of structure is changed, and the internal force of the most members is lower, which creates favorite condition for multilevel fortification of structures under earthquake action. With the increase of the storey of the RC frames, the effect of steel concentric X-centrically steel braces on structural seismic responses is decreased. Compared with RC frames, the inter-storey drift ratio in RC-XCSB frames of 5-storey, 8-storey and 12-storey can be reduced by up to 36%, 24% and 20%, respectively.