基于DEM-FDM耦合的平行隧道间钢套管下旋施工影响研究  

Influences of backspin construction of steel casing between parallel tunnels based on DEM-FDM coupling method

作　　者：徐泽宇 杨涛 周小波 XU Zeyu;YANG Tao;ZHOU Xiaobo(The Third Construction Co.,Ltd.of China Construction Fifth Engineering Bureau,Changsha 410004,China;China Construction Fifth Engineering Division Co.,Ltd.,Changsha 410004,China)

机构地区：[1]中建五局第三建设有限公司,湖南长沙410004 [2]中国建筑第五工程局有限公司,湖南长沙410004

出　　处：《岩土工程学报》2025年第1期207-216,共10页Chinese Journal of Geotechnical Engineering

摘　　要：采用离散元-有限差分耦合数值方法研究平行隧道间钢套管下旋施工的影响。根据工程实例建立数值模型,并通过对比模拟值与实测值验证了数值分析方法的合理性。数值模型分析了双隧道-静压、双隧道-旋压、单隧道-旋压等3种工况下隧道和土层的受力变形特性。结果表明:钢套管旋压施工导致隧道产生的横向位移为静压施工的163.5%,单隧道工况下的隧道横、竖向变形分别较双隧道工况增加32.7%和53.4%;旋压相较于静压可以有效减小管片的收敛变形,而单隧道工况的收敛变形为双隧道工况的2倍;旋压工况下,随钢套管沉入深度增加,旋转指数先增加后减小,最大值发生在套管下沉至隧道拱顶附近,而在静压工况下需重点关注竖向旋转引起的管片错位;对于双隧道-旋压工况,应重点关注施工初期由于土体水平位移引起的地层变位和施工后期土体竖向位移可能导致的机械倾覆和钢套管的垂直度误差;隧道管片应力分布区域及特征与钢套管动态施工过程紧密相关,应在不同阶段采用相应的管片补强措施。The coupled numerical method of the discrete element method(DEM)and finite difference method is used to study the influences of backspin construction of steel casing between parallel tunnels.A numerical model is established based on the field tests,and the numerical analysis method is verified by comparing the simulated values with the measured ones.The load-deformation characteristics of tunnels and soil layers under three working conditions,i.e.,double-tunnel-static pressure,double-tunnel backspin and single tunnel backspin,are analyzed by numerical model.The results indicate that the transverse displacement caused by backspin construction of steel casing is 163.5%of that under the static pressure,and the transverse and vertical deformations under single tunnel increase by 32.7%and 53.4%,respectively,compared with those of double tunnels.Compared under the static pressure,the backspin can effectively reduce the convergence deformation of segments,and the convergence displacement under single tunnel is twice that under double tunnels.Under the backspin,the rotation index increases first and then decreases with the vertical displacement of the steel casing,and the maximum value occurs near the displacement of the casing to the tunnel arch.Under the static pressure,the dislocation of the segment caused by vertical rotation should be focused.Under the double-tunnel-backspin,the stratum displacement caused by horizontal displacement of soil at the initial stage of construction should be concerned,and the possible mechanical overturning and the vertical error of steel casing caused by vertical displacement of soil at the later stage of construction should be focused.The stress distribution area and characteristics of tunnel segment are closely related to the dynamic construction process of steel casing,and the corresponding segment reinforcing measures should be adopted at different stages.

关 键 词：桩基础 隧道工程 离散元-有限差分法 钢套管 受力变形 

分 类 号：TU470[建筑科学—结构工程]