砂泥岩地层浅埋大跨暗挖地铁车站转序落底关键技术

KEY TECHNOLOGIES FOR SHALLOW BURIED AND LARGE SPAN UNDERGROUND EXCAVATION OF SUBWAY STATIONS IN SANDSTONE STRATA

大断面暗挖地铁车站工程采用双侧壁导坑法施工,该方法是处理软岩地层、浅埋地段等不利条件下的常用施工技术手段。结合重庆轨道交通18号线北延工程黄沙溪站暗挖车站开挖工艺及施工步序,利用midas GTS建立的计算模型,分析车站中洞开挖对车站围岩和初期支护结构的应力、位移特征及稳定性的影响,通过现场监控量测及自动化应力监测,进一步验证了提前解除车站两端优化中洞的安全性、可靠性、经济性,有力保障了车站隧道的安全施工及毗邻既有建(构)筑物的安全,可为同类工程提供借鉴和参考。

The double-sided wall excavation method is commonly used in the construction of large section underground subway station projects,which is a common construction technique for dealing with unfavorable conditions such as soft rock strata and shallow buried areas.This project combines the excavation process and construction steps of the Huangshaxi station hidden excavation station in the northern extension project of Chongqing metro line 18.Using the calculation model established by midas GTS,it analyzes the impact of excavation of the middle tunnel on the stress,displacement characteristics,and stability of the surrounding rock and initial support structure of the station.through on-site monitoring and automated stress monitoring,it further verifies the safety,reliability,and economy of early release of the optimized middle tunnel at both ends of the station,this effectively ensures the safe construction of station tunnels and the safety of adjacent existing structures,providing reference and guidance for similar projects.