考虑桩-土作用的PHC管桩极限变形及其影响因素分析

Analysis of ultimate deformation and its influencing factors of PHC pipe pile considering pile-soil interaction

单调荷载作用下PHC管桩的极限变形是判断结构损伤的一项重要参数。为了解桩、土参数对PHC管桩在单调荷载作用下变形的影响,采用ABAQUS有限元软件的纤维梁单元模型和共结点法,建立考虑桩土相互作用的PHC管桩有限元模型,使用P-y土弹簧模拟桩土相互作用,混凝土采用UCONCRETE03本构模型,预应力纵筋采用USTEEL02本构模型,分析配筋率、桩基入土深度、土体不排水抗剪强度、轴压比等参数对PHC管桩极限变形的影响规律。计算结果表明:桩基极限位移随桩基配筋率的提高而增加,但随桩基入土深度、土体不排水抗剪强度、轴压比的增加而减少,并拟合单调荷载作用下的PHC桩基极限位移的计算公式。

The ultimate deformation of pre-stressed high-strength concrete PHC pipe pile under monotonic load is an important parameter to judge the structural damage.In order to solve the effect of pile and soil parameters on the ultimate deformation of PHC pipe pile under monotonic load,we establish the finite element model of PHC pipe pile considering pile-soil interaction by the fiber beam element model of ABAQUS software and the common node method,and use the P-y soil spring to simulate the pile-soil interaction.We apply UCONCRETE03 constitutive model and USTEEL02 constitutive mode,and analyze the influences of reinforcement ratio,buried depth,undrained shear strength of soil,and axial compression ratio on the ultimate deformation of PHC pipe pile.The results show that the ultimate displacement of PHC pipe pile increases with the reinforcement ratio increasing,and decreases with the depth,undrained shear strength of soil,and axial compression ratio increasing.