顶管施工对周边环境的扰动机制研究

Disturbance Mechanism of Pipe-Jacking Construction on Surrounding Environment

为确定顶管施工对周边环境的影响,通过收集工程数据并结合案例监测结果,对顶管施工引起的地表和既有隧道变形机理及规律进行了研究。结论表明:(1)地表断面沉降规律符合Peck公式,影响范围约为1.4~2.6倍顶管直径,地表变形发展曲线分为“先隆起后沉降”和“全程沉降”两种形式;(2)既有隧道上浮总体呈现“反向”Peck曲线,上浮量受既有隧道刚度和所受扰动大小影响,随着时间的增加上浮量先快速增加后趋于稳定;(3)对上穿既有隧道顶管工程进行监测和分析,地表和隧道变形规律与已有研究规律基本一致,采取了数种措施以控制地表和既有隧道的变形,地表最大沉降量约11 mm,既有隧道最大上浮量约1.6 mm。研究成果可为相关顶管设计和施工提供一定参考。

To determine the impact of pipe-jacking construction on the surrounding environment,engineering data was collected and combined with case monitoring results to study the mechanism and laws of surface and existing tunnel deformation caused by pipe-jacking construction.The conclusions are as follows:(1)The settlement law of the surface section conforms to the Peck formula,with an influence range of about 1.4~2.6 times the diameter of the top pipe.The surface deformation development curve is divided into two forms:"uplift first and then settlement"and"full settlement".(2)The overall uplift of existing tunnels presents a"reverse"Peck curve,and the uplift amount was affected by the stiffness of the existing tunnel and the magnitude of the disturbance it is subjected to.With the increase of time,the uplift amount first increases rapidly and then tends to stabilize.(3)Monitoring and analysis were conducted on the pipe-jacking project of the existing tunnel,and the deformation patterns of the surface and tunnel were basically consistent with existing research patterns.Several measures were taken to control the deformation of the surface and existing tunnel,with a maximum settlement of about 11 mm on the surface and a maximum uplift of about 1.6 mm on the existing tunnel.The research results can provide certain references for the design and construction of related pipe-jacking.