多年冻土区桩基础荷载传递规律及影响因素模拟研究  

Simulation and Study of Load Transfer Law and Influencing Factors of Pile Foundations in Permafrost Regions

作　　者：王博通 宋焕东 高樯 葛英兰 刘国祥 臧洋 WANG Bo-tong;SONG Huan-dong;GAO Qiang;GE Ying-lan;LIU Guo-xiang;ZANG Yang(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Xinjiang Xinneng Electric Power Construction Technology Development Co.Ltd.,Urumqi 830002,China;State Key Laboratory of Frozen Soil Engineering,Northwest Institute of Ecological Environment and Resources,ChineseAcademyof Sciences,Lanzhou 730000,China)

机构地区：[1]兰州理工大学土木工程学院,兰州市730050 [2]新疆新能电力建设科技发展有限公司,乌鲁木齐市830002 [3]中国科学院西北生态环境资源研究院冻土工程国家重点实验室,兰州市730000

出　　处：《公路》2025年第2期154-162,共9页Highway

基　　金：国家自然科学基金项目,项目编号42301163,42371140;冻土工程国家重点实验室自主课题,项目编号SKLFSE-ZQ-202102;甘肃省科技计划项目,项目编号23JRRA670。

摘　　要：桩侧土体的性质与分布、桩体长径比是影响桩基础荷载传递规律的主要因素。桩周土体强度高、塑性强,且受含冰量和温度的直接控制,是冻土区桩基础的独有特征。充分理解冻土区桩基础的荷载传递规律及影响因素,不仅有助于冻土区基础工程的设计施工,而且对桩基础变形防控有重要指导意义。利用界面库仑摩擦模型和可以反映土壤塑性的Drucker—Prager准则,模拟计算了不同条件下冻土桩基础的荷载传递过程和承载力变化。结果表明,冻土区桩基础的荷载~位移曲线分为线性段、加速段、破坏段;降低土体温度、减小桩径可以降低线性段的变形斜率,提高极限荷载;而增加桩长会增大极限荷载,但不会显著影响线性段的变形斜率。总体而言,侧摩阻力在线性变形段呈R形分布并由上向下逐步发挥,在极限荷载后呈现正梯形分布;温度越低,桩径越小,桩越长,则桩侧中下部侧摩阻的滞后效应就越显著;桩侧土体热力性质的差异及分布,扩大了侧摩阻力分布的异化特性;桩侧上部土体温度越低,越有利于冻土桩基础的承载性能。The properties and distribution of soil on the side of pile and the ratio of pile length to diameter are the main factors that affect the load transfer law of pile foundation.The soil around the pile has high strength,strong plasticity,and is directly controlled by ice content and temperature,which are the unique characteristics of pile foundation in permafrost area.A fully understanding of the load transfer law and influencing factors of pile foundations not only helps with the design and construction of pile foundations in permafrost areas,but also has important guiding significance for deformation prevention and control of pile foundations.In the paper,the interface Coulomb friction model and the Drucker Planck matching Mohr Coulomb criterion which can reflect soil plasticity are used to simulate and calculate the load transfer processs and bearing capacity changes of frozen soil pile foundations under different conditions.The results show that the load displacement curve of pile foundation in permafrost areas can be divided into linear segment,acceleration segment,and failure segment.Reducing soil temperature and pile diameter can reduce the slope of the linear deformation segment and increase the ultimate load,while increasing pile length does not significantly affect the slope of the linear deformation segment,but will increase the ultimate load.In general,the frictional resistance exhibits an R-shaped distribution in the linear deformation segment and gradually develops from top to bottom,and a trapezoidal distribution after the ultimate load.The lower the temperature of the upper soil on the pile side,the more favorable it is for the bearing capacity of frozen soil pile foundations.

关 键 词：桥梁工程 多年冻土 桩基础 荷载传递 有限元分析 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]