不同叠交角度下盾构重叠隧道地层位移规律研究

Study on the strata displacement law of overlapping shield tunnels with different overlapping angles

以以色列“红线轻轨”项目重叠隧道为背景,在分析现场监测数据的基础上采用Rhino6和FLAC3D软件建立了三维数值模型,研究了不同隧道叠交角度下盾构重叠隧道地表沉降、地层位移规律。研究结果表明,2条隧道从平行逐渐过渡到重叠状态时,随着叠交角度的增加隧道中间处测点累计沉降量增大,但累计沉降量除了受叠交角度影响外,还与穿越地层情况密切相关;在本工程地层条件下,由于2条隧道均穿越松散的库卡K1地层,叠交角度为60°时地表累计沉降达到最大。后建隧道开挖完成后,隧道叠交角度小于45°时,沉降槽宽度增大;大于45°而小于60°时,沉降槽宽度基本不变;大于60°时,沉降槽宽度减小;达到90°时,沉降槽左右对称。两侧隧道开挖完成后,隧道叠交角度达到75°时,两侧地层均改变移动方向。研究成果为重叠隧道的设计和施工提供参考。

Based on the overlapping tunnel of Tel Aviv Red Line Light Rail Project in Israel,this study established a three-dimensional numerical model by using Rhino6 and FLAC3D software on the basis of analysis of on-site monitoring data,to investigate the ground settlement and stratum displacement laws of shield overlapping tunnel at different overlapping angles.Results show that when the two tunnels gradually transit from horizontal to overlapping state,with the increase of overlapping angle of the two tunnels,the accumulated settlement at the measuring points in the middle of the two tunnels increases,but the accumulated settlement is not only affected by overlapping angle,but also closely related to the stratum traversing situation.Under the stratum condition of the project,when the overlapping angle is 60°,the accumulated surface settlement reaches the maximum because both tunnels pass through the loose reservoir K1 stratum.When the overlapping angle of the rear-built tunnel is less than 45°after excavation,the width of the settlement trough increases.When the overlapping angle is larger than 45°and smaller than 60°,the width of the settlement trough remains unchanged.The width of settlement trough decreases when the overlapping angle is larger than 60°.When the overlapping angle reaches 90°,the settlement trough is symmetrical on both sides.After excavation of tunnels on both sides,when the overlapping angle of the tunnels reaches 75°,the strata on both sides change the direction of movement.This research offer reference for the design and construction of overlapping tunnels.