考虑地基刚度分区的能源支护桩有限元模拟

Finite Element Simulation of Energy Pile-anchor Retaining Structure Considering Subgrade Stiffness Partition

能源支护桩在工程实践中已有应用,但国内外相关研究甚少。以雄安城市计算(超算云)中心能源支护桩的应用为背景,使用COMSOL Multiphysics软件对深基坑桩锚支护结构进行了基坑开挖和变温过程的有限元模拟。在开挖模拟中通过对比模拟结果和现场实测数据,优化了模型参数设置,提出了同时考虑回弹区土体的卸载状态、剪切区土体的小应变刚度以及土体刚度随深度增加而增大的“地基刚度分区”建模思路;在基坑开挖模拟的基础上,研究了不同温度荷载对支护桩变形和内力的影响,并对如何在工程设计计算中考虑温度荷载对支护桩的影响提出建议。结果表明,考虑地基刚度分区的建模方法能有效优化基坑开挖线弹性模型的模拟结果,温度荷载对支护桩的变形和内力影响较小,工程设计时可以忽略。

Energy piles have been applied in engineering practice as retaining piles,but there is little research at home and abroad. Based on the application of energy retaining piles in Xiongan Urban Computing(Supercomputing Cloud)Center,numerical simulations are conducted to study the excavation of a deep foundation pit and temperature change process of energy retaining piles using COMSOL Multiphysics software. In the excavation simulation,the model parameter setting was optimized by comparing the simulation results with the field measured data,and the“subgrade stiffness partition”modeling method for the foundation soil was proposed. Furthermore,the influence of different temperature loads on the deformation and internal force of the retaining pile is studied. Finally,based on the above analysis results,suggestions are put forward on considering the influence of temperature load on the retaining pile in engineering design calculation. The results show that the modeling method considering subgrade stiffness partition can effectively optimize the simulation results of the linear elastic model of foundation pit excavation. The temperature load has little influence on the deformation and internal force of the retaining pile,which can be ignored in engineering design.