矩形管廊顶管施工对邻近管线的影响研究

Influences of pipe-jacking of rectangular utility tunnels on adjacent pipelines

顶管施工引起的地层移动造成邻近管线产生不均匀沉降甚至破坏,而以往研究顶管、土体与邻近管线相互作用的有限元方法大多借鉴盾构的模拟方式,未考虑土体变形受到掘进机约束以及顶推的持续扰动作用的影响,造成计算结果不准确。基于Plaxis 3D平台建立管廊、土体及邻近管线相互作用的三维有限元模型,通过土体收缩率模拟地层损失带来的影响,并结合实测数据提出了适用于顶管施工特点的土体收缩率的确定方法。在此基础上,对顶管掘进参数进行敏感性分析,总结出施工的最优掘进参数。结果表明,基于土体收缩率模拟顶管施工的计算结果与实测数据吻合良好,模拟可靠。与既有研究相比,考虑了顶管施工过程中掘进机约束作用以及顶推持续扰动的作用,这与实际工程更加接近。

The ground motion caused by pipe jacking will induce uneven settlement and even damage on the adjacent pipelines.However,most previous finite element studies on pipelines-soil-tunnel interaction have used shield modeling as a reference without considering the influences of the restraint effects of the tunneling machine and continuous disturbance in the construction process of pipe jacking,resulting in inaccurate calculated results.The three-dimensional finite element model for pipelines-soil-tunnel interaction is established by using the Plaxis 3 D software.The influences caused by formation loss is simulated by soil contraction,and based on the measured data,a method for determining the soil contraction suitable for pipe jacking is proposed.Then,the sensitivity analysis of the influencing factors of pipe jacking construction is carried out to summarize the optimal driving parameters of construction.The results of this study show that the calculated results are in good agreement with the measured data and the simulation is reliable.Unlike the previous researches,in this study the influences of the restraint effects of the tunneling machine and continuous disturbance in the construction process of pipe jacking are considered,which is closer to the real projects.