落锚贯入深度有限元模拟及与经验公式对比

Numerical Simulation of Dropping Anchor Penetration Depth and Comparison with Empirical Fomula

为了在工程实际中更高效地制定兼具安全性与经济性的海底管道铺设方案,对落锚贯入深度进行研究。应用Abaqus建立多组底质及落锚条件下的有限元模型,基于耦合欧拉-拉格朗日(Coupled Eulerian-Lagrangian,CEL)法进行落锚贯入的动力响应数值模拟,将有限元结果与现有试验数据及经验公式进行对比分析。有限元结果与试验数据整体吻合性良好,具有较强的参考性。与美国土木工程师协会(ASCE)及挪威船级社(DNV)规范中不同公式进行比较发现:在沙土摩擦角大、黏土不排水剪切强度大的条件下,有限元与公式结果吻合度更大;随落锚重量增大,公式结果较有限元结果保守度增加。

In order to determinate a safe and economical subsea pipe laying plan efficiently in engineering practice,the penetration depth of dropping anchor is studied.The finite element models with multiple sets of bottom materials and anchors are built by Abaqus.Based on the Coupled Eulerian-Lagrangian(CEL)method,the dynamic response numerical simulation of anchor dropping penetration is carried out,and the simulation results are compared with the existing data of test and empirical formula.The finite element results are consistent with the test data as a whole and therefore are of certain referential value.Compared with the formulas in ASCE and DNV codes,it is found that:under the condition of sand with larger friction angle and clay with larger undrained shear strength,the results of finite element and formula approach each other;as the anchor weight increases,the formula results are more conservative compared with the finite element results.