中文摘要：

依据模拟钻井船在黏土层中插桩对邻近桩影响的离心模型试验结果,研究了通过耦合欧拉-拉格朗日（CEL）有限元计算并结合非线性地基梁有限元计算,分析钻井船插桩对邻近桩影响问题的可行性。CEL有限元方法将产生大变形的土体设为欧拉体,采用欧拉有限元方法计算该区域的变形响应,计算过程中,欧拉体的空间网格形状、大小位置保持不变,物质可在网格之间运动;其他土体设为拉格朗日体,采用拉格朗日有限元方法计算变形响应,计算过程中,物质的运动和网格的变形保持一致。运用罚函数方法实现欧拉体与拉格朗日体的耦合。通过CEL有限元计算,可以确定钻井船插桩导致的邻近桩桩身水平位移。进一步通过非线性地基梁有限元模型计算确定桩身弯矩。计算结果表明,利用CEL有限元方法并结合非线性地基梁有限元方法计算出的桩身位移和弯矩沿桩长的变化与离心模型试验结果基本一致。说明采用CEL有限元方法并结合非线性地基梁有限元方法分析黏土层中插桩对邻近桩的影响问题是可行的。CEL有限元模型中欧拉土体范围的设置对计算结果有明显影响。研究表明,若插桩深度小于0.75倍桩靴直径,可将欧拉土体范围设置成1.00~1.25倍桩靴直径;若插桩深度大于0.75倍桩靴直径,将欧拉土体范围取为插桩深度以下0.5倍桩靴直径是恰当的。

英文摘要：

Based on the results of the centrifuge modeling, the possible effect of spudcan penetration on an adjacent pile is analyzed based on the coupled Eulerian- Lagrangian（CEL） FEM method and the nonlinear foundation beam FEM method. In the CEL FEM method, the strata with large deformation are set as the Eulerian domain, and the deformation responses of the domain are calculated by an Eulerian finite element algorithm. Eulerian meshes are fixed in the space and materials can move through meshes during calculations. Other strata are set as the Lagrangian domain and deformation responses of the domain are calculated by the Lagrangian finite element algorithm during calculations. Material movements are consistent with deformations of meshes for the Lagrangian finite element algorithm. Eulerian and Lagrangian domains are coupled by the penalty function method. Lateral displacements along the adjacent pile due to the spudcan penetration are determined by CEL finite element analyses. Bending moments along the pile are further determined by nonlinear foundations beam finite element calculations. It is shown that the variations of lateral displacements and bending moments along the pile are consistent with the results of centrifuge model tests, showing that effects of the spudcan penetration on an adjacent pile can be analyzed by using the CEL finite element method and the nonlinear foundation beam finite element method. It is also shown that the Eulerian stratum depth has a significant effect on the CEL calculation results. If the spudcan penetration depth is less than 0.75 times the diameter of the spudcan, the Eulerian stratum depth is set as 1 to 1.25 times the diameter of the spudcan. If spudcan penetration depth is larger than 0.75 times the diameter of the spudcan, the Eulerian stratum depth should be set as 0.5 times the diameter of the spudcan below the spudcan penetration depth.