浅埋暗挖法隧道下穿城市道路地表沉降分析

Analysis of Surface Settlement of Undercut Tunnels Passing through Urban Roads by Shallow-buried Tunnelling

以贵阳地铁2号线一期工程某区间隧道工程为对象,统计分析浅埋暗挖地铁施工的地表沉降数据,研究其沉降规律。结果表明:掌子面前后45 m范围内为沉降主要影响区;地表沉降经历前期稳定、变形、趋于稳定及稳定四个阶段,变形速率是规范控制值3 mm/d的89%~178%,稳定时间为30~80天,平均稳定时间为65天;地表沉降值分布概率与伽玛曲线吻合较好,沉降值小于5 mm和大于70 mm的发生的频率均不超过10%,50%以上的地表沉降值超过了30 mm的控制标准,地表沉降超过某一控制值的概率分布函数符合hill1函数模型。

Taking an interval tunnel project of phase 1 of Guiyang Metro Line 2 as the research object,the surface settlement data of the shallow buried underground subway tunnelling has been analyzed statistically in order to study the law of road settlement.The results show that the major affected area of settlement is within 45 m in front and behind of the face.The surface subsidence has experienced four stages:early stabilization,deformation,tending to stability and stability.The deformation rate is 89%~178%of the standard control value of 3 mm/d.The data stability time is 30~80 days,and the average stability time is 65 days.The distribution probability of surface subsidence is in good agreement with the gamma curve,the occurrence frequency of subsidence less than 5mm and greater than 70 mm is less than 10%,and more than 50%of surface subsidence exceeds the control standard of 30 mm,and the probability distribution function of surface subsidence exceeding a certain control value conforms to hill1 function model.