自升式平台层状地基条件下插桩过程数值模拟研究

对于采用独立式桩靴结构的自升式平台,桩靴的入泥深度是保障平台安全作业的关键问题之一。采用ABAQUS软件的Explicit求解器,以位移增量步方式计算地基极限承载力;在施加初始地应力场的前提下,引入无限元边界处理方法,考虑了土壤无限大边界条件的影响,并使用ALE自适应网格技术有效地解决了土壤模型的大变形问题;最后,将有限元计算与经验公式计算进行比对分析。结果表明,在一定预压载荷条件下,有限元计算结果能较全面精确地反映插桩结果,弥补经验公式考虑参数单一、无法解决层状土承载力之间不连续问题以及无法动态模拟插桩过程的不足。

Numerical Analysis of Jack-up Spudcan Penetration for Multi-layered Critical Soil

Spudcan penetration depth is an important issue for the safe and stable operation of the jack-up structures with independent footings foundation concept. The ultimate bearing capacity of spudcan foundation was calculated by the commercial finite element program ABAQUS/Explict based on displacement-controlled method. The finite element large deformation analyses ,which was carried out by introducing the infinite element boundary after applying the initial geostatic stress field, was treated effectively by applying ALE （Arbitrary Lagrange-Euler） adaptive meshing. The results from both the finite element calculation and the conventional empirical formulas were compared and analyzed. Finite element analysis can show the capacity variation during the spudcan penetration comprehensively and accurately with the preloading condition. It is also capable to consider multiple soil parameters, discontinuity behavior of capacity in layered soil and the penetration process, which are incapable for empirical formulas.