偏压荷载对某地铁连通道基坑支护设计的影响分析

Influence analysis on pit lateral supporting design of a metro connect channel under eccentric loading

城市地下交通是城市的生命线工程,地铁连通道因其功能需要往往建在环境复杂地区,以连通和方便人流直接进出商业、办公场所。本文结合上海某地铁连通道工程,基于有限元MidasGTS分析软件,分析了在偏压荷载作用下基坑支护体的变形特征,根据偏压荷载大小和环境保护要求,优化了基坑支护设计参数。对于承受偏压荷载的围护体部位,重点加大围护体钻孔灌注桩桩径、加长灌注桩桩长,通过提高围护体刚度和增加桩体插入比来提高围护体抵抗偏压荷载作用的能力。本文介绍了在偏压荷载作用下的基坑工程的设计方法,可为类似偏压荷载作用下的基坑工程设计与施工提供参考。

Underground traffic is urban lifeline. The subway connection channel is often need to be built in complex environment due to it should have the function to convenient the people. The deformation characteristics of lateral supporting under eccentric load is analyzed using the finite element analysis software Midas GTS for a project of subway connect channel in Shanghai. Based on the eccentric load and environmental protection requirements, the design parameters are optimized, the fortifying measures including increasing pile diameter,lengthening the pile are adopted to increase the supporting stiffness and increasing the insertion ratio to strengthen the anti eccentric loading capacity. The design method of pit supporting under eccentric load is introduced which would be a reference for the similar excavation supporting design and construction.