摘要
为深入研究湿陷性黄土浸水后桩基的力学特性,研究了浸水后的桩基在竖向初始荷载作用下的受力变化,推导了单桩和群桩的负摩阻力估算公式,充分考虑桩身弹性压缩、桩身蠕变和桩端沉降等因素,求解了桩基中性点处轴力,并分别求得单桩和群桩的桩端承载力。结果表明:以试坑浸水试验值为标准值,单桩桩端承载力公式解误差为11.4%,有限元解误差为8.88%;群桩桩端承载力公式解误差为8.59%,有限元解误差为6.67%。使用文中估算公式进行计算,误差在12%以内,可为湿陷性黄土地区桩基设计提供参考。
In order to study the mechanical properties of the pile foundation after soaking in collapsible loess,the change of the force of the pile foundation after soaking in water under the vertical initial load is studied,the negative friction of single pile and group pile is deduced,the axial force at the neutral point of the pile foundation is solved,and the bearing capacity of single pile and group pile is obtained respectively,taking the elastic compression of pile body,creep of pile body and settlement of pile end into full consideration.The results show that the error of the formula of bearing capacity of single pile is 11.4%and the error of the finite element solution is 8.88%;The solution error of bearing capacity formula of pile group is 8.59%,and that of finite element is 6.67%.The error is less than 12%,which can provide reference for pile foundation design in collapsible loess area.
作者
毛忠安
陈恒大
MAO Zhongan;CHEN Heng da(Land Surveying,Planning and Design Institute of Shaanxi Land Engineering Construction Group Co.,Ltd.,Xi’an 710075,China;Shaanxi Land Engineering Construction Group Co.,Ltd,Xi’an 710075,China;Xi’an Natural Resources and planning Bureau,Xi’an 710016,China)
基金
陕西省土地工程建设集团内部科研项目“湿陷性黄土场地桩的负摩阻力合理取值对桩基承载力的影响研究”(DJNY2018-01).
关键词
湿陷性黄土
桩端承载力
桩侧负摩阻力
桩侧正摩阻力
数值分析
collapsible loess
bearing capacity of pile tip
negative friction of pile side
positive friction of pile side
numerical analysis
