黏土地基静压桩贯入机制模型试验与数值仿真

Model test and numerical simulation of intrusion mechanism of jacked pile in saturated coarse soil

结合ABAQUS有限元软件具有处理大变形和非线性问题的优势,考虑到土体的弹塑性本构关系、桩—土的接触类型以及土体初始应力的影响,并采用位移贯入法和Mohr-Coulomb准则,建立了静压桩位移贯入土体的有限元模型,实现了桩体的连续贯入,探讨了沉桩过程中桩周土的土中应力以及桩—土界面孔隙水压力随贯入深度的变化规律,明确了沉桩过程中的挤土效应,并将模拟结果与室内模型试验结果进行比较,发现二者的吻合度较高。研究结果可为静压桩的设计与施工提供参考。

With the advantage of ABAQUS in solving large deformation and nonlinear problems and taking into account the elastic-plastic constitutive relation of soil,the contact type of pile-soil and the influence of soil initial stress,a finite element model for the intrusion displacement of a static pressure pile into a soil mass was established by the displacement penetration method and the Mohr-Coulomb criterion.Additionally,the penetration process of the pile was also simulated.The variation of the soil stress and pore water pressure with the penetration depth of the pile was discussed,and the squeezing effect in pile driving process was clarified.Then we compared the results of simulation with the results in the laboratory test and found an excellent consistent.The research results can provide basis for the study of static pile driving process.