超大直径盾构下穿高铁路基的沉降数值分析  

Numerical simulation analysis of settlement for super-large diameter shield tunneling undercrossing high-speed railway subgrade

作　　者：娄洪峻 苏栋[1,2,3] 林星涛 王雪涛 宋明 LOU Hongjun;SU Dong;LIN Xingtao;WANG Xuetao;SONG Ming(College of Civil and Transportation Engineering,Shenzhen University,Shenzhen 518060,Guangdong Province,P.R.China;Key Laboratory for Resilient Infrastructures of Coastal Cities(MOE),Shenzhen University,Shenzhen 518060,Guangdong Province,P.R.China;Shenzhen Key Laboratory of Green,Efficient and Intelligent Construction of Underground Metro Station,Shenzhen University,Shenzhen 518060,Guangdong Province,P.R.China;China Communications Construction Company Second Highway Consultant Co.Ltd.,Wuhan 430056,Hubei Province,P.R.China)

机构地区：[1]深圳大学土木与交通工程学院,广东深圳518060 [2]深圳大学滨海城市韧性基础设施教育部重点实验室,广东深圳518060 [3]深圳大学深圳市地铁地下车站绿色高效智能建造重点实验室,广东深圳518060 [4]中交第二公路勘察设计研究院有限公司,湖北武汉430056

出　　处：《深圳大学学报（理工版）》2024年第3期377-386,共10页Journal of Shenzhen University(Science and Engineering)

基　　金：国家自然科学基金资助项目(51938008,52090084)。

摘　　要：为探究超大直径盾构隧道下穿城际铁路路基沉降规律,以中国武汉两湖隧道工程为例,基于Plaxis有限元软件,建立了铁路路基-土体-隧道的三维精细化数值模型,探讨盾构掘进过程中地层损失率、开挖面支护压力、盾尾注浆压力对隧道上方城际铁路路基沉降的影响.结果显示,盾构下穿复合地层的过程中,高铁路基道砟层表面在盾构掘进方向上会发生不同程度的沉降;当盾构掘进引起的地层损失率从1.0%增加到1.6%时,铁路路基的最大沉降从18.86 mm增加到22.71 mm,增大了20.4%;当开挖面支护力处于隧道拱顶侧向静止土压力的0.7~1.4倍时,不同工况下盾构掘进引起的铁路路基变形差异较小(小于0.67 mm);注浆压力对铁路路基的沉降影响明显,随着注浆压力增大,铁路路基的沉降明显减小.当隧道拱顶注浆压力增大到拱顶侧向静止土压力的3倍(648 kPa)或以上时,沿铁路路基的最大差异沉降未超过规范要求(≤5 mm/10 m).研究结果可为超大直径盾构下穿高铁路基时掘进参数的设置提供参考.To explore the settlement characteristics of intercity railway subgrade induced by super-large diameter shield tunneling,taking the Lianghu Tunnel Project in Wuhan as an example,we establish a three-dimensional refined numerical model of the railway subgrade-soil-tunnel by using the finite element software Plaxis.The influences of the ground loss ratio,tunnel face support pressure,and grouting pressure at the shield tail on the settlement law of the intercity railway subgrade above the tunnel are investigated during shield tunneling.The simulation results show that during the process of shield penetration into the composite strata,the surface of the ballast layer of the high speed railroad foundation experiences varying degrees of settlement in the direction of shield tunnel excavation.When the ground loss ratio caused by shield tunneling increases from 1.0%to 1.6%,the maximum settlement of the railway subgrade increases by about 20.4%from 18.86 mm to 22.71 mm.When the tunnel face support force is 0.7 to 1.4 times the lateral static earth pressure of the tunnel vault,the difference in the deformation of the railway subgrade caused by shield tunneling under different tunnel face support pressures is minor(less than 0.67 mm).The grouting pressure obviously influences the settlement of the railway subgrade.As the grouting pressure increases,the settlement of the railway subgrade decreases significantly.When the grouting pressure of the tunnel crown increases to 3 times the lateral static earth pressure of the crown(648 kPa)or more,the maximum differential settlement along the railway subgrade does not exceed the specification requirement(≤5 mm/10 m).The results of the study can provide references for setting excavation parameters for the super-large-diameter shield undercrossing high-speed railway subgrade.

关 键 词：隧道工程 超大直径盾构 盾构施工 下穿铁路 沉降控制 地表沉降 数值模拟 

分 类 号：TU455.43[建筑科学—岩土工程]