钢楔式活络端的工作原理与试验验证

Working Principle and Test Verification of Steel Wedge Type Active Node

在基坑工程内撑式围护结构中,钢楔式活络端是钢支撑体系的重要传力构件之一,但是普遍认为该伸缩式节点并不能满足设计要求,且稳定性差。然而,关于钢楔式活络端的研究大多数停留在定性分析上,没有可靠的定量计算或试验数据。为了定量研究常用的单厢式和双厢式活络端的力学特性,并且验证活络端是否满足设计要求,在北京地铁工地抽取了3组活络端作为试件,在试验室进行了加载试验,得到了3种活络端的P-△曲线。通过搜集设计院关于活络端的设计计算方法计算得到了活络端的设计承载力及设计极限承载力。

In the braced excavation engineering,the steel-wedge active node is an important force transmission component in steel supporting structure systems. However,it is generally believed that the stretch-out and draw-back joint cannot meet the requirements of the practical engineering design and its stability is very weak. Up to now,most of the studies on the active nodes remain qualitative and there is no reliable quantitative calculation or experimental data. In order to quantitatively study the mechanical characteristics of the two kinds of active nodes including single-box active node and double-box active node,which are widely used in practical engineering,single axial compression tests on these nodes which were taken as specimens at the Beijing subway construction site have been conducted in laboratory. The P-Δ curves of the specimens were obtained from these tests. The design bearing capacity and ultimate bearing capacity of the active node are obtained by collecting the design calculation method of the Design Institute on the active node.