Abstract
To our knowledge, the “Yangtze Estuary No. 2” ancient shipwreck was salvaged using the world’s first curved pipe jacking curtain method. For underground construction in the underwater soft soil environment, this study employs the Material Point Method (MPM) to analyze the resulting large geotechnical deformations. Vertically variable depth construction, a characteristic feature of the novel underwater shipwreck integral salvage method (which uses tight-radius rectangular curved pipe jacking to form a bottom tray), presents difficulties in determining the corresponding excavation jacking force. Therefore, the frictional resistance variation along the entire vertical curved pipe jacking was first derived, obtaining the required jacking force at different positions during construction as key input parameters for the MPM simulation. Then, the MPM numerical solutions were compared with the results of a 1∶10 scaled experiment for validation. A full-scale MPM numerical model of shipwreck salvage construction was built to study the environmental impact of the curved pipe jacking process and its soil deformation mechanisms. The results show that during the curved pipe jacking construction process, the soil near the jacking end experienced significant disturbance, with vertical displacements of −17 cm to −16 cm observed on the initial jacking side after construction. Validated against on–site measured data analysis, the jacking force calculation method established in this paper yields higher accuracy (an average improvement of 36.79%). Compared with conventional numerical simulation methods, the displacement distribution obtained by MPM is closer to the actual observations. Under the influence of the jacking load, the ship hull experienced approximately 16 cm of displacement on the jacking side, and the maximum displacement difference between both sides of the hull was about 9 cm. The research findings provide practical guidance for thrust calculation and refined evaluation of construction disturbance in underwater curved pipe jacking excavation with variable overburden.