上第三系富水粉细砂地层隧道综合施工技术

Comprehensive Construction Technology for Tunnel Construction in Upper Tertiary Water-rich Silty Fine Sand Stratum

为研究某铁路隧道在穿越上第三系富水粉细砂地层施工综合技术,解决溜塌、涌砂、初支沉降变形大等影响安全质量技术问题,结合数值仿真计算软件模拟实际施工过程,分析隧道采用“地表降水+帷幕注浆”的施工效果。总结了隧道开挖过程中初支位移变化特征;分析了砂层含水率对工程开挖的影响;总结了上第三系富水粉细砂地层隧道“地表降水+帷幕注浆”超前支护综合施工技术。施工开挖过程中隧道变形趋势与仿真计算结果拟合度较高,说明了仿真手段的可实施性,为后续类似地层条件下隧道开挖提供借鉴依据。

In order to study the comprehensive construction technology for a railway tunnel crossing the Upper Tertiary water rich silty fine sand stratum,and solve the technical problems affecting safety and quality such as collapse,sand gushing,and large initial support settlement deformation,numerical simulation calculation software was used to simulate the actual construction process,and the construction effect of"surface precipitation+curtain grouting"for the tunnel was analyzed.The variation characteristics of initial support displacement during tunnel excavation are summarized;The influence of sand moisture content on engineering excavation is analyzed;This paper summarizes the comprehensive construction technology of"surface precipitation+curtain grouting"advanced support for tunnels in the Upper Tertiary water rich silty fine sand stratum.The high degree of fit between the tunnel deformation trend and the simulation calculation results during construction and excavation indicates the feasibility of the simulation method,providing a reference basis for subsequent tunnel excavation under similar stratum conditions.