地铁深基坑钢支撑预加轴力分析

Analysis on Pre Axial Force of Steel Support in Deep Foundation Pit of Subway

在钢支撑施工中面临着预加轴力大小难于控制、设计轴力与实际轴力偏差较大、固定端钢板易被轴力计挤压变形等棘手问题,本文运用钢支撑加力现场测试、钢支撑轴力监测数据统计分析、建立有限元模型模拟分析等手段,深入研究了钢支撑加力施工及发挥支撑作用阶段的轴力变化规律,合理解释了钢支撑轴力设计值与实际值较大偏差的原因,得出了钢支撑有效锚固系数变化范围及其主要影响因素,确定了钢支撑固定端合理的加固措施,并成功运用于现场钢支撑施工中,较好地指导了后续钢支撑施工,也为类似地铁车站基坑钢支撑的设计与施工提供了一定的借鉴。

The steel support construction now is facing many tough problems. For example,the prestress value of steel support is difficult to control,the deviation between design axial force and actual axial force is large,the fixed end plate of steel support is easily out of shape when squeezed by the axial force meter. Three research methods are used in this paper including field test in the process of imposing prestress on steel support,monitoring data analysis of axial force of steel support and numerical simulation analysis. In this paper,the variation laws of axial force of steel support are deeply analyzed during steel support being imposed prestress and playing a supporting role stage,the reasons of large deviation between design axial force and actual axial force are reasonably interpreted,the range of effective anchorage coefficient of steel support and its main influencing factors are obtained, the reasonable reinforcement measures for the fixed end plate of steel support are determined and successfully applied to the steel support construction in this project. Through this paper,a good guide to the follow-up steel support construction in this project and a certain reference for steel support design and construction in other similar project in subway station foundation pit are provided.