当结构在土体中运动时,往往导致土体发生较大的变形,此类问题采用大变形数值分析方法更为恰当。耦合欧拉-拉格朗日(Coupled Eulerian-Lagrangian,简称CEL)法是大变形数值分析方法中的一种,在分析大变形问题时具有很强的适用性,但在国内尚未开展CEL法分析锚板承载力的研究。以方形锚板在均质土及线性土中的拔出试验为原型,基于CEL法建立数值模型,对锚板的极限承载力及破坏机制进行研究,并通过用户自定义子程序,实现了线性土的强度分布随锚板拔出而变化。计算结果表明,土体杨氏模量越大,锚板的极限承载力越大;随着位移增大,锚板的抗拔力先增大,后降低;当埋深小于临界埋深时,土体发生整体破坏;当埋深大于等于临界埋深时,土体发生局部破坏。数值计算反映的规律与试验结果基本吻合,体现了CEL法模拟锚板在海床中大位移响应的出色能力。
Large deformation of soil will occur when the structure moves through the soil, which is more appropriate to be analyzed by large deformation finite element method. Coupled Eulerian-Lagrangian(CEL) method is one of the most suitable method of the large deformation finite element methods. In China, there is no research on the ultimate capacity of plate anchors using the CEL method. Two pull-out model tests including square anchors in uniform and linear clay are taken as prototypes to build numerical models with the CEL method. Comparative studies are conducted between the model tests and numerical models on the ultimate capacity of plate anchors and the failure mechanism of soil. With a user-defined subroutine, the linear shear strength of soil can be updated with the mobilization of the anchor. The results show that the ultimate capacity of the anchor increases with the Young's modulus, when the pullout force of the anchor increases with the displacement to a peak value at the beginning and followed by a decrease. If the embedment ratio is lower than the critical value, general failure mechanism can be observed. Contrarily, localized failure mechanism will develop. The numerical results agree well with model tests, demonstrating that the CEL method can well simulate the complete response of the anchor of large mobilization.