摘要
为探究串珠状溶洞对超长桩基承载特性的影响,以广西某高速铁路项目兴业特大桥桩基建设为工程背景,采用有限元软件ABAQUS建立相应数值仿真模型,考虑4种不同溶洞数量、3种不同溶洞间距下的桩基下穿溶洞计算工况。结果表明:在溶洞的影响下,岩溶地基中的桩基与非岩溶地基中的桩基在轴力、侧摩阻力、应力分布等方面与常规桩基有显著差异。岩溶地基中的桩基荷载-位移曲线随荷载增大由线性发展转化为抛物线型;桩身轴力随深度的增加而减小,且在穿过溶洞区段其轴力保持不变;桩侧摩阻力受溶洞的影响而存在多个极值点,其位置一般位于溶洞上部一定区域。溶洞间距一定时,桩基的承载能力随溶洞数量的增加而降低,当溶洞数量一定时,桩基的承载力随着溶洞间距的减小而降低。
In order to explore the influence of beaded karst caves on the bearing characteristics of ultra-long pile foundation,taking the pile foundation construction of Xingye super large bridge of a high-speed railway project in Guangxi as the engineering background,the finite element software ABAQUS was used to establish the corresponding numerical simulation model,considering the calculation conditions of pile foundation passing through karst caves under four different karst caves and three different karst cave spacing.The results show that under the influence of karst cave,the pile foundation in karst foundation and non-karst foundation are significantly different from conventional pile foundation in axial force,lateral friction resistance and stress distribution.The load-displacement curve of pile in karst foundation changes from linear development to parabolic shape with the increase of load.The axial force of pile decreases with the increase of depth,and the axial force remains unchanged in the section passing through karst cave.Due to the influence of the cave,there are many extreme points of pile side friction,which are generally located in a certain area in the upper part of the cave.The bearing capacity of the pile decreases with the increase of the number of caves,and the bearing capacity of the pile decreases with the decrease of the distance between caves when the number of caves is constant.
作者
李龙起
徐雷
胡忠良
赵玉印
李学友
LI Longqi;XU Lei;HU Zhongliang;ZHAO Yuyin;LI Xueyou(College of Environment and Civil Eng.,Chengdu Univ.of Technol.,Chengdu 610059,China;China Railway Second Bureau Group No.4 Company,Chengdu 610031,China)
出处
《建筑结构》
北大核心
2023年第S02期2401-2405,共5页
Building Structure
基金
国家自然科学基金项目(42277149)
中铁二局科技研发计划(二局四司科2021字第10号)。
关键词
铁路桥梁
荷载传递特性
数值计算
超长桩基
串珠状溶洞
railway bridge
load transfer characteristics
numerical calculation
super long pile foundation
beaded karst cave
