层状地基静压PHC管桩连续贯入有限元模拟

Finite Element Simulation on Continuous Penetration of StaticPressure PHC Pipe Pile in Layered Foundation

借助ABAQUS有限元软件,考虑土体的弹塑性本构关系以及初始应力场影响,采用Mohr-Coulomb屈服准则,模拟静压桩在连续贯入层状地基中的受力性能,揭示静压PHC桩在沉桩过程中桩周土体径向应力、竖向应力及径向、竖向位移的演化规律,明确沉桩过程中的挤土效应和侧阻退化效应。结果表明,PHC管桩在连续贯入过程中,贯入阻力随贯入深度的模拟值与实测值基本吻合,验证模型的有效性。桩周土中的径向应力、竖向应力与土层性质密切相关,当桩端由黏性土层贯入砂层时,径向应力和竖向应力均出现退化现象,静压桩贯入过程对于桩周土径向位移影响要高于竖向位移,研究成果可为静压桩的理论研究与工程实践提供借鉴与参考。

With the help of ABAQUS finite element software,considering the elastoplastic constitutive relation of soil and the influence of initial stress field,the Mohr-Coulomb yield criterion was used to simulate the mechanical performance of jacked pile in continuous penetration layered foundation.The evolution law of radial stress,vertical stress,radial and vertical displacement of soil around jacked PHC pile during pile sinking was revealed,and the squeezing effect and lateral resistance degradation effect during pile sinking were clarified.The results show that in the continuous penetration process of PHC pipe pile,the simulated value of penetration resistance with penetration depth is basically consis-tent with the measured value,which verifies the validity of the model.The radial stress and vertical stress in the soil around the pile are closely related to the properties of the soil layer.When the pile end is penetrated from the cohesive soil layer into the sand layer,the radial stress and vertical stress are degraded.The influence of the penetration process of the static pressure pile on the radial displacement of the soil around the pile is higher than the vertical displacement.The research results can provide reference for the theoretical research and engineering practice of the static pressure pile.