单层导洞暗挖车站桩基差异沉降计算方法研究

Study on Calculation Method of Differential Settlement of Piles in Single-layer Pilot Tunnel of Excavation Station

通过分析国内外桩基沉降计算方法及其基本原理,结合单层导洞暗挖车站的结构受力特征,提出了单层导洞暗挖车站边桩及中柱桩基的沉降计算方法;基于单排桩基础计算桩基沉降,并采用考虑桩径影响的明德林解计算桩端平面以下地基中由基桩引起的附加应力。采用该方法计算北京地铁16号线万泉河桥站的桩基差异沉降,分析不同施工工况下的沉降规律,并与现场实际监测数据进行了对比分析,结果表明理论计算值与现场沉降监测值较为接近,均能满足规范要求。

By analyzing the calculation methods and basic principles of pile foundation settlement at home and abroad,combined with the structural stress characteristics of single-layer pilot tunnel underground excavation station,the calculation method of settlement of side pile and middle column pile foundation of single-layer pilot tunnel underground excavation station is proposed.The settlement of pile foundation is calculated based on single row pile foundation.Considering the influence of pile diameter,the additional stress caused by piles in the foundation below the pile end plane is calculated by using Mindlin solution.The settlement calculation method is used to calculate the differential settlement of pile foundation of Wanquanheqiao,which is single-layer pilot tunnel underground excavation station in Beijing metro line 16,analyze the settlement law under different construction conditions,and compare with the actual monitoring data.The theoretical calculation value is close to the on-site settlement monitoring value and can meet the specification requirements to ensure the safety of station structure during the construction process.