基于有效应力法的不排水条件下大直径管桩水平循环动力响应数值分析  

Numerical analysis of horizontal cyclic responses of large-diameter pipe piles under undrained conditions based on effective stress method

作　　者：曹光伟 欧强 丁选明[1,2] 周鹏[1,2] CAO Guangwei;OU Qiang;DING Xuanming;ZHOU Peng(College of Civil Engineering,Chongqing University,Chongqing 400045,China;Key Laboratory of New Technology for Construction of Cities in Mountain Area,Chongqing University,College of Civil Engineering,Chongqing 400045,China)

机构地区：[1]重庆大学土木工程学院,重庆400045 [2]重庆大学山地城镇建设与新技术教育部重点实验室,重庆400045

出　　处：《中南大学学报（自然科学版）》2023年第5期1905-1915,共11页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51878103);中国博士后科学基金资助项目(2021M693740);重庆市自然科学基金资助项目(cstc2020jcyj-cxttX0003)。

摘　　要：基于有效应力原理和黏土边界面塑性本构模型,开发适用于ABAQUS/Explicit的VUMAT子程序。在此基础上,研究不同循环幅值与桩径对软黏土大直径单桩水平响应的影响。研究结果表明:本文所开发程序可有效模拟循环荷载下土体的孔压和位移累积特性与刚度退化行为;循环次数与桩泥线处的桩累积变形大致呈线性关系,受加载幅值比影响;卸载刚度退化与桩累积变形成幂函数关系,且桩径增加,退化趋于严重;对于大直径海洋单桩,桩底易出现超孔压累积,其累积量受循环幅值控制;桩径对超孔压累积量不敏感,但桩径增加后其影响区域显著增加。Based on the effective stress principle and clayed bounding surface plastic constitutive model,a material subroutine VUMAT suitable for the undrained analysis in ABAQUS/Explicit was developed,and the effects of the cyclic amplitude and pile diameter on the horizontal responses of large-diameter monopiles in soft clay were studied.The results show that the subroutine can effectively simulate the accumulation characteristics of the pore pressure and displacement of the soil and the stiffness degradation behavior of the clay under cyclic loads.The number of cycles has an approximately linear relationship with the pile's cumulative deformation at the mudline,and the deformation is affected by the load amplitude ratio,the degeneration of unloading stiffness has a power function relationship with the cumulative deformation,and the degeneration increases with the increase of pile diameter.For large-diameter monopiles,the excess pore pressure tends to accumulate at the pile bottom,whose cumulative amplitude is controlled by the cyclic amplitude ratio.However,the pile diameter is not sensitive to the accumulation of excess pore pressure,and the influence area increases significantly when the pile diameter increases.

关 键 词：数值模拟 二次开发 循环荷载 大直径管桩 

分 类 号：TU473[建筑科学—结构工程]