K_o固结饱和土沉桩引起的超静孔隙水压力  

Excess Pore Water Pressure Caused by Driving Pile in K_o Consolidated Saturated Soils

作　　者：刘时鹏[1] 李建勇[1] 张兴胜[1] 何志宇[1] Liu Shipeng;Li Jianyong;Zhang Xingsheng;He Zhiyu(College of Resources and Environment, North China University of Water Resources and Electric Power, Zhengzhou 450011, P.R. China)

机构地区：[1]华北水利水电大学资源与环境学院,郑州450011

出　　处：《地下空间与工程学报》2018年第2期430-435,共6页Chinese Journal of Underground Space and Engineering

基　　金：华北水利水电大学高层次人才科研启动项目(201406)

摘　　要：根据饱和粘土中沉桩特点,用柱孔扩张理论模拟其贯入过程,将扩张后周围土体分为塑性区和弹性区,由柱孔扩张基本平衡方程和边界条件,采用能够考虑天然状态土体实际固结性状的K_o固结土体本构模型的屈服面方程为屈服准则,以对数应变考虑桩周土体发生的大变形,结合Henkel孔压公式,推导出沉桩后桩周超静孔隙水压力的理论表达式。通过算例分析了土体剪切模量、临界状态应力比、超固结比和静止侧压力系数对超静孔隙水压力的影响。同时,与基于修正剑桥模型解答和工程实例进行对比分析,理论计算值和现场实测值吻合较好,表明理论结果的合理性与实用性。Based on the characteristic of driving pile in saturated clay soils,the cylindrical cavity expansion theory is selected to simulate penetration process,the soil around the cylindrical cavity is classified into plastic zone and elastic zone. According to the cylindrical cavity expansion theory and boundary conditions,the elasto-plastic constitutive model which considers actual K_o consolidated soils characteristics,a logarithmic strain which considers soil large strain around piles and Henkel formula,the theoretical expression of excess pore water pressure is obtained.Meanwhile,the influence of soil shear modulus,critical state stress ratio,overconsolidation ratio and static earth pressure coefficient on excess pore water pressure is analyzed. Additionally,a comparative results between the modified Cam-clay model solution and engineering example indicate that the analytical solutions of excess pore water pressure are in good agreement with the in-situ measured values,the rationality and practicability of the solution is verified.

关 键 词：Ko固结土体本构模型 沉桩 超固结比 超静孔隙水压力 

分 类 号：O319.56[理学—一般力学与力学基础]