基于CEL和ALE方法的自升式平台桩基贯入过程瞬态研究

Penetration Transient Study on Pipe-foundation about Jack-up Platform Based on CEL and ALE Algorithms

为研究桩基过程中桩端极限承载力、桩靴上部空腔的形成、发展和破坏机理,桩土贯入过程中桩端土体流动及土体应力分布变化,采用两种方法来处理地基土体高度扭曲的网格,并与相关地土工离心模型试验实验结果进行对比,结果表明:ALE方法较CEL方法可更好地保证地应力稳定性;桩土贯入过程中桩端土体回流优于空腔垂直壁面剪切破坏是空腔破坏的主要原因,ALE数值结果与离心试验结果一致;ALE方法保证材料-边界-网格的一致性运动,模拟桩端极限承载力较CEL更加真实、可靠。ALE方法对于桩基贯入过程中的瞬态研究结果优于CEL方法。

To research the spudcan bearing capacity, the cavity formation, development and failure mechanism and the soil back-flow and the distribution of the soil stress in pile-soil penetration process, two algorithms are adopted, and the numerical simulation results are compared with the related geotechnical centrifugal model test.The results show that the geotechnical stress of the foundation is more stable in ALE than CEL.The ALE result are consistent with the geotechnical centrifugal model test.The spudcan bearing capacity is more realistic and believable in ALE model than CEL model, because the ALE algorithm ensured the consistency of the material-boundary-mesh.The ALE algorithm is superior to CEL algorithm in the penetration mechanism of pipe-foundation in dynamic process.