城市轨道交通车站出入口大断面顶管工程穿越城市道路的沉降控制技术  

Settlement Control Techniques for Urban Rail Transit Station Entry/Exit Large Profile Pipe Jacking Engineering through Urban Roads

作　　者：邢慧堂 刘浩 王栋 李鹏飞 周华 张炎 XING Huitang;LIU Hao;WANG Dong;LI Pengfei;ZHOU Hua;ZHANG Yan(Jinan Rail Transit Group Co.,Ltd.,250014,Jinan,China;College of Civil and Transportation Engineering,Hohai University,210098,Nanjing,China;China Railway 21st Bureau Group Rail Transit Engineering Co.,Ltd.,250117,Jinan,China)

机构地区：[1]济南轨道交通集团有限公司,济南250014 [2]河海大学土木与交通学院,南京210098 [3]中铁二十一局集团轨道交通工程有限公司,济南250117

出　　处：《城市轨道交通研究》2024年第4期177-180,185,共5页Urban Mass Transit

摘　　要：[目的]为了确保城市轨道交通车站出入口顶管施工项目顺利实施,应对该工程穿越城市道路时地层的沉降影响及沉降控制措施进行研究。[方法]结合济南轨道交通R2线长途汽车站站出入口顶管工程,在阐述该工程地质条件及重难点的基础上,建立了大断面顶管工程穿越地下管线密集的城市道路的三维数值计算模型,得到了距开挖面不同距离时的地面沉降曲线,以及不同埋深处土层的沉降曲线。对比了顶管中轴线上方地面监测点竖向位移模拟计算值与现场实测值随开挖距离的变化情况。提出相应的施工优化措施,并结合现场实测数据对优化效果进行分析验证。[结果及结论]顶管施工时,随着与顶管中轴线距离的增大,地面沉降量逐渐减小;随着深度的增加,土层深层位移逐渐增大,且沉降曲线逐渐由“矮胖型”变成“瘦高型”。现场受土舱压力波动较大、顶管与地层存在摩擦扰动等因素的影响,模拟计算得到的最大沉降量略小于现场实测的最大沉降量,二者间存在一定差异。通过采取控制掘进速度、合理压浆以减少摩阻力等措施后,后续施工沉降控制效果明显,地面最大沉降为18.18 mm,变形在施工允许范围内。[Objective]To ensure the smooth implementation of urban rail transit station entry/exit pipe jacking construction project,it is essential to study the impact of ground settlement and explore settlement control measures for its engineering through urban roads.[Method]With reference to the long-distance bus station entry/exit pipe jacking engineering on Jinan Rail Transit R2 Line,and based on the description of project geological conditions and key difficulties,a 3D numerical calculation model for large profile pipe jacking engineering through urban roads with dense underground pipelines is established.Land subsidence curves at different distances from the excavation face and settlement curves at different depths of the soil layer are obtained.A comparison is made between the simulated vertical displacement values of land monitoring points above the pipe central axis and the field-measured values changing with excavation distances.Corresponding construction optimization measures are proposed,and the optimization effects are analyzed and verified based on field-measured data.[Result&Conclusion]During the jacking process,as the distance from pipe central axis increases,the land subsidence gradually decreases.With increasing depth,the deep layer displacement of the soil layer gradually increases,and the settlement curve gradually transitions from′stout and short′to′slender and tall′.Factors such as significant fluctuations in soil chamber pressure and frictional disturbance between the pipe and the stratum on-site lead to an outcome of the maximum simulated settlement,which is slightly less than the maximum field-measured settlement,posing certain discrepancy.By adopting measures such as controlling excavation speed and rational grouting for reducing friction,the subsequent construction settlement control effect is evident,with a maximum land subsidence of 18.18 mm,and the deformation is within construction allowable range.

关 键 词：城市轨道交通出入口 顶管隧道施工 下穿施工 FLAC 3D软件 沉降控制 

分 类 号：U231.4[交通运输工程—道路与铁道工程] U215.8