高频液压振动沉桩的颗粒离散元分析  

DEM study on the installation of a pile using the high frequency hydraulic vibratory hammer

作　　者：韩钧[1] 陈福全[1] 曹琪君[1] 

机构地区：[1]福州大学土木工程学院,福建福州350108

出　　处：《福州大学学报（自然科学版）》2011年第2期287-292,共6页Journal of Fuzhou University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(50778045);山东省自然科学基金资助项目(ZR2009FM071)

摘　　要：采用颗粒离散元方法,分析在高频振动沉桩过程中对桩贯入深度的影响因素,研究在桩贯入不同深度时桩周砂土速度场、接触应力场的变化及整桩贯入后不同砂土深度的孔隙率值.数值模拟结果表明,提高桩的静定荷载和激振频率能提高桩的贯入深度.桩周砂土速度场和应力场变化揭示了桩侧摩阻力作用机理和表层土体的隆起现象.随着桩的贯入,桩周砂土的接触应力增大.整桩贯入后,深层砂土的孔隙率降低,表明高频液压振动打桩能致密深层砂土,提高桩的竖向承载力.Using particle discrete element method （DEM）, the factors influencing the pile penetration depths in the course of the installation of a pile using the high frequency hydraulic vibratory hammer are analyzed. The change in the velocity field of sand and contact stress field when the pile penetrating the different depths is studied. Numerical simulation results show that the pile penetration depth in- creases when the static load and the vibration frequency increase. The variations of the velocity field and contact stress field reveal the mechanisms of the pile shaft frictional resistance and the uplift phe- nomenon of topsoil. The contact stress of sand increases as the pile is being driven. When the total pile is penetrated in the sand, the porosity of the deep sand reduces, which indicates the high frequency hydraulic vibratory pile driving can densify the deep sand.

关 键 词：高频振动沉桩 颗粒离散元 砂土 贯入深度 孔隙率 

分 类 号：TU473.1[建筑科学—结构工程]