冻土区静钻根植桩竖向承载特性数值模拟研究
Numerical Simulation Study on Vertical Bearing Characteristics of Static Drilling Grounding Pile in Frozen Soil Area
王兴珍 1杨庚辰 1詹钦鹏2
作者信息
- 1. 石家庄铁道大学 土木工程学院,河北 石家庄 050043
- 2. 石家庄铁道大学 土木工程学院,河北 石家庄 050043;中铁十一局集团第一工程有限公司,湖北 襄阳 441100
- 折叠
摘要
基于静钻根植桩结构特点,利用 ABAQUS 建立三维有限元模型,开展静钻根植桩在冻土区的桩基承载特性数值模拟研究,分析竖向荷载下桩基荷载传递机理,讨论桩周冻土温度、桩周水泥土厚度和水泥土黏聚力对竖向承载特性的影响.结果表明,水泥土外壳是桩基承载力的关键,其竖向应力变化复杂;水泥土扩大头底部竖向应力较顶部增大了 43%左右;竹节上下部位会发生应力突变,水泥土外壳竹节凹陷处下部较上部应力平均增大 27.5%.桩周冻土常温与负温条件下桩基承载特性具有一定差异;桩周水泥土厚度应介于 100 mm 到 0.5 倍预制芯桩桩径之间;水泥土黏聚力在 300 MPa左右对桩基承载力最有利.
Abstract
Based on the structural characteristics of static drilling grounding pile,the three-dimen-sional finite element model was established by ABAQUS to conduct numerical simulation research on the pile bearing characteristics of static drilling grounding pile in frozen soil area.The load transfer mecha-nism of pile foundation under the vertical load was analyzed,and the influence of frozen soil tempera-ture,cement soil thickness and cement soil cohesion on the vertical bearing characteristics were dis-cussed.The results show that the cement shell is the key to the bearing capacity of pile foundation,and the vertical stress change is complicated;The vertical stress at the bottom of the cement soil expansion head increases about 43%over the top;The stress at the lower surface increases by 27.5%over the up-per part.There are certain differences in the bearing characteristics of pile foundations under normal and negative temperature conditions of frozen soil around piles;The thickness of cement soil around pile should be between 100 mm to 0.5 times the pile diameter of precast core pile;The cohesive force of about 300 MPa is most favorable to the bearing capacity of pile foundation.
关键词
冻土区/静钻根植桩/桩基承载特性/桩周冻土温度/桩周水泥土厚度/水泥土黏聚力Key words
frozen soil area/static drill rooted pile/pile bearing characteristics/pile permafrost tem-perature/thickness of cement soil around the pile/cement soil cohesive force引用本文复制引用
出版年
2024
NETL
NSTL
万方数据