Abstract:
To investigate the disturbance behavior and parameter design of pipe jacking in soft and water-rich strata, a series of physical model tests was conducted using a self-developed testing system. The variations in jacking force, soil pressure, and surface vertical displacement during the jacking process were analyzed. The results show that the evolution of jacking force consists of three stages: the initial stage, the transition stage, and the stable stage. Its variation rate is jointly influenced by jacking velocity and grouting pressure. A higher jacking velocity helps mitigate the decay of jacking force, whereas a moderate increase in grouting pressure can reduce the force magnitude and suppress fluctuations. However, under high jacking velocity, the mitigation of soil disturbance becomes limited. Soil pressure exhibits pronounced fluctuations, with the peak position shifting forward along the jacking direction as the jacking velocity increases. A higher grouting pressure can lower the peak magnitude and reduce the distance to its occurrence. Surface vertical displacement is primarily characterized by uplift near the centerline, with an affected range extending to approximately four times the pipe width on each side. Increasing grouting pressure significantly restrains surface displacement, while excessive jacking velocity exacerbates surface settlement. Moreover, there exists an optimal matching relationship between jacking velocity and grouting pressure that minimizes soil disturbance.