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

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 3D 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.