不同埋深下近距交叠隧道施工地表变形研究

摘要

为研究不同埋深下近距交叠隧道施工引起的地表变形交互影响效应，以青岛地铁2号线枣山李村站与3号线万年泉李村站相互交叠区间隧道为工程原型。通过FLAC3D动态模拟和分析不同埋深下地表变形规律可知：不同埋深下地表变形趋势不同，埋深越大，受下穿施工影响越小，纵向变形逐渐由双峰沉降曲面向单峰沉降过渡；不同埋深下变形区域不同，埋深越大，变形区域逐渐由交叠隧道沿线向交叠区域中心发展；当埋深超过30 m时，下穿施工对地表影响较小；同时，提出不同埋深下地表沉降变形趋势经验公式。并结合工程应用验证上述分析的可靠性及适用性。%To study the effect of surface deformation in different depths in small spacing overlapping tunnels during construction, Qingdao metro overlapping tunnel is referenced where Zaoshan-Licun station on line No. 2 and Wannianquan-Licun station on line No. 3 are intercrossing. FLAC3D is used for dynamic simulation, and the surface deformation law in different depth is analyzed. The results show that:surface deformation differs in different depths, the deeper the depth, the less surface deformation impacted by construction, and longitudinal surface subsidence curves gradually changes from twin peaks to single peak;deformation region differs in different depths, the deeper the depth, surface deformation region gradually changes from along the line to the center; when the tunnel depth is over 30m, construction effect to surface subsidence deformation is small. With reference to engineering practices, empirical formula of surface deformation curve in different depths is put forward and verified for reliability and applicability.