外张拉式自复位方钢管混凝土柱脚的受力性能和设计方法研究

Study on structural performance and design method of external tensioned type self-centering concrete filled square steel tubular column base

基于空间铰接机制,提出了一种外张拉式自复位方钢管混凝土柱脚节点,对其进行了受力性能分析,提出了设计方法,并建立有限元模型进行验证.结果表明:外张拉式自复位方钢管混凝土柱脚节点能够实现铰接机制,满足结构的空间变形要求,并具有较好的自复位能力.其脱开弯矩与方钢管混凝土柱截面尺寸、柱子轴力及初始预应力大小有关.柱子转动过程中,自复位柱脚的抗弯能力由初始预应力、预应力筋拉力增量、柱子轴力及防屈曲钢板受拉产生的力提供.自复位柱脚的耗能集中于可更换的耗能构件,可实现震后的快速修复.

Based on spatial hinged mechanism, an external tensioned type self-centering concrete filled square steel tubular（CFSST） column base was put forward. The structural performance analysis and design method were conducted, and the results were validated using the finite element analysis. The results show that the external tensioned type self-centering column base meets the requirement of the spatial hinged mechanism and deformation, and has good capability of self-centering. The decompression moment is related to the CFSST column section size, column axial force and initial PoSt-tensioned force. The flexural ability is produced by the initial post-tensioned force, the post-tensioned force increment due to the post-tensioned tendons elongation, column axial force and the tension of the buckling restrained steel plate. The energy dissipation is concentrated on the replaceable energy dissipation components, i.e. the buckling restrained steel plate, and the rapid repair can be realized after earth- quake.