基坑工程钢支撑高脚螺栓-模袋混凝土固支端及其承载性能

A fixed end composed of high-foot bolt and bag concrete for steel supporting and its bearing capacity in foundation pit engineering

基坑工程钢支撑端节点是位于钢管端部和基坑侧壁之间的连接构件,其功能为承受并传递钢支撑轴力,并可少量调节钢支撑拼装长度。但实际工程中钢支撑体系的失稳破坏多数为节点刚度或强度不足造成的,节点弱化可能导致基坑的连续坍塌破坏。本文在分析基坑工程事故原因的基础上,设计了一种钢支撑高脚螺栓-模袋混凝土固支端,阐述了新型固支端的结构组成、工作原理及施工工艺流程,通过有限元数值模拟手段分析了固支端结构的抗压、弯承载性能。结果表明固支端具有可调节支撑长度、施加预应力的特点,其抗压、弯刚度大,承载力高,承载性能主要与材料强度、短接头长度相关。

The steel support end node of the foundation pit engineering is a connecting member located between the end of steel tube and the sidewall of foundation pit. Its function is to withstand and transfer the axial force of steel support, and the assembly length of the steel support can be adjusted in a small amount. However, most of the instability and damage of the steel support system in practical engineering is caused by the insufficient stiffness or strength of the joints. The weakening of joints may lead to the progressive collapse damage of the foundation pit. Based on the analysis of accident,a fixed end mainly composed of high-foot bolt and bag concrete is designed for steel supporting. Its structure composition,working principle and construction process is expounded. And its compressive and flexural bearing performance are analyzed by finite element model numerical simulation. The results show that the fixed end has the characteristics of adjustable support length, prestressing, high compressive, bending rigidity, and high bearing capacity. The bearing capacity is mainly related to the strength of the material and the length of the short joint.