750kV变电构架柱头节点静力性能试验研究

Experimental study on static behavior top-joint of 750 kV substation truss structures

变电构架柱头节点作为一种重要的传力部件将决定整榀构架的安全性,且占用很大一部分用钢量.以国内首例750 k V钢管混凝土变电构架工程——甘肃桥湾750 k V变电站为背景,按考虑顶板和剪切板厚度不同的两种构造措施设计了两个1:2缩尺节点,并对其进行了单调静力试验.试验结果表明,两种节点均能满足工程要求,且有较高的安全储备和延性,节点最终破坏模式均为非节点区杆件破坏,而节点区各板件应力水平尚处于弹性状态、内填混凝土完好,符合"强节点弱杆件"的设计原则.

The top-joint of herringbone truss-column is a key force transmission component which affects the safety of the whole structure,and it will take a large amount of steel consumption simultaneously.Based on the engineering background of the first CFT 750 k V substation named Qiaowan substation in China's Gansu province,two different constructional details of 1:2 scale CFT top-joint specimens,one with more thick shear plate and the other more thick top plate respectively,were designed and applied on the monotonic static test.Test results indicate that the two kinds of top-joints can meet the engineering requirement,and have sufficient safety reserves and ductility.The failure pattern of two joints are non-joint region failure,while each plate at the joint region is still in elastic stress level and the filled concrete is flawless,in accordance with the design concept of 'strong-joint and weak-member.