软土地层双圆盾构掘进对周围土体扰动分析  

Analysis of Soil Disturbance Caused by Tunneling of Double-circle Shield Tunnel (DOT) in Soft Soil Stratum

作　　者：陈小亮[1,2,3] 周松国[3] 朱世煜 Chen Xiaoliang;Zhou Songguo;Zhu Shiyu

机构地区：[1]浙江大学,浙江杭州310027 [2]浙江大学滨海和城市岩土工程研究中心,浙江杭州3100272 [3]杭州市市政工程集团有限公司,浙江杭州310006

出　　处：《城市道桥与防洪》2019年第5期232-236,M0025,共6页Urban Roads Bridges & Flood Control

基　　金：国家自然科学基金资助项目(51338009)

摘　　要：双圆盾构具有断面形式特殊、开挖面积相对较大的特点,其推进将引起较大的地层扰动,而过大的土体扰动往往引发一系列环境病害。依托上海某双圆地铁隧道区间工程,构建三维弹塑性有限差分模型,计算分析双圆盾构掘进引起的地表位移场以及土体应力场分布,并将数值模型计算结果和现场监测数据进行对比验证。研究表明:双圆盾构施工引起的地表变形横向分布基本符合正态分布,影响区域主要集中在轴线两侧2倍盾构宽度范围内;切口到达时地表隆起,盾尾离开后,后方土体产生沉降,脱离20环左右地表纵向沉降逐渐趋于稳定;盾构掘进对下部土体的影响相对较小,盾构底部土压力增加最小,盾构中轴线上方土压力增量最大。研究成果可为今后此类施工提供理论依据和前期指导。DOT has the characteristics of special section and relatively large excavation area. Its tunneling will cause the larger disturbance of stratum. And too large soil disturbance usually leads to a series of environmental diseases. Relying on a DOT project of metro in Shanghai, 3Delastic-plastic finite difference model is established to calculate and analyze the distribution of surface displacement field and soil mass stress field caused by DOT tunneling. The calculation result of the numerical model and the field monitoring data are compared and verified. The study results show that the transverse distribution of surface deformation caused by the DOT construction is basically in line with the normal distribution. And the influence area is mainly concentrated in the 2 times of the shield width on both sides of the axis. At the time of the incision, the surface of the earth is raised, while the rear soil mass is sinking after the shield tail leaves. The longitudinal settlement of the ground surface is stabilized gradually from20 rings. The influence of shield tunneling on the lower soil is relatively small, the earth pressure at the bottomof the shield is the minimumand the earth pressure increment is the maximumin the upper part of the axis in shield. The study results can provide some theoretical basis and prophase guidance for the similar projects in the future.

关 键 词：软土地层 双圆隧道 地表沉降 土压力分布 有限差分法 

分 类 号：TU443[建筑科学—岩土工程]