摘要
为验证上软下硬富水地层新建叠线盾构始发对端头地表沉降和临近隧道管片变形的影响,本文以南京地铁6号线岗子村站始发端头为背景,建立三维有限元数值模型,模拟分析了始发端头未加固、袖阀管注浆加固、三轴搅拌桩加固和人工冻结+三轴搅拌桩联合加固4种不同加固工况下的地表沉降,模拟结果表明本工程采用袖阀管加固的地表沉降最小,经过实测验证了该方法合理可行.通过改变袖阀管加固范围、既有线与新建叠线水平和竖向净距、新建叠线竖向净距,对不同工况下的新建叠线始发进行了敏感性分析.结果表明:袖阀管注浆加固宽度应在隧道拱腰两侧2m以上;当袖阀管加固深度下界为隧道底部0.5D(隧道直径)时,综合考虑地表沉降和下线隧道变形,加固上界应在上线隧道顶部0.6D以上,新建叠线竖向净距应控制在0.3D~1.2D,既有线与新建叠线水平净距应在0.6D以上;而新建叠线隧道埋深不变时,改变既有线与新建叠线竖向净距对既有线管片变形影响较小.
To verify the influence of the initiation of the new stacked shield in the soft and hard water-rich strata on the surface settlement of the end and the deformation of the adjacent tunnel segments,a threedimensional finite element numerical model was established in this paper based on the starting end of Gangzicun Station of Nanjing Metro Line 6,and the surface settlement under four different reinforcement conditions,namely the non-reinforcement of the starting end,the grouting reinforcement of the sleeve valve pipe,the reinforcement of the triaxial mixing pile and the artificial freezing of the three-axis mixing pile,was simulated and analyzed.The simulation results show that the surface settlement reinforced by sleeve valve tube is the smallest,and the method is reasonable and feasible through actual measurement.By changing the reinforcement range of the sleeve valve tube,the horizontal and vertical clear distance between the existing line and the new stacked line,and the vertical clear distance of the new stacked line,the sensitivity analysis of the new stacked line under different working conditions was carried out.The results show that the grouting reinforcement width of the sleeve valve pipe should be more than 2 m on both sides of the tunnel arch waist.When the lower limit of the reinforcement depth of the sleeve valve pipe is 0.5D(the diameter of the tunnel)at the bottom of the tunnel and considering the surface settlement and the deformation of the downline tunnel,the upper limit of the reinforcement should be more than 0.6D at the top of the upper line tunnel,the vertical net distance of the new stacked line should be controlled at 0.3D~1.2D,and the horizontal net distance between the existing line and the new stacked line should be more than 0.6D.However,when the buried depth of the new stacked line tunnel remains unchanged,changing the vertical net distance between the existing line and the new stacked line has little effect on the deformation of the existing line segment.
作者
杨平
于游
朱俊
王加辉
何云
YANG Ping;YU You;ZHU Jun;WANG Jiahui;HE Yun(College of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China;China Railway Fifth Bureau Group Sixth Engineering Company,Chongqing 401147,China)
出处
《三峡大学学报(自然科学版)》
北大核心
2025年第4期53-63,共11页
Journal of China Three Gorges University:Natural Sciences
基金
国家自然科学基金项目(42101127)。
关键词
盾构始发
叠线隧道
数值模拟
袖阀管注浆
临近既有隧道
shield starting
stacked tunnels
numerical simulation
sleeve valve pipe grouting
adjacent to existing tunnels
