湿陷性黄土地区桩基负摩阻力试验研究  

Study on Negative Friction Force of Pile Foundations in Collapsible Loess Area

作　　者：陈新泽[1] 胡昕[1] 张希宏[1] 

机构地区：[1]中国能源建设集团西北电力设计院,陕西西安710032

出　　处：《电力勘测设计》2015年第1期11-16,19,共7页Electric Power Survey & Design

基　　金：西北电力设计院技术创新项目(XB1-TM12-2010)

摘　　要：结合湿陷性黄土地区桩基浸水载荷试验实例,对桩基的负摩阻力形成机理进行数值模拟研究,分析桩长、桩顶荷载、地表超载、桩端土模量和固结时间等因素对负摩阻力的影响,得出以下结论:桩顶荷载引起桩体的沉降,桩越短,沉降越大,沉降的速率越快;随着桩顶荷载的增大,中性点明显上移,负摩阻力引起的下拽力减小,其趋势逐渐变缓;随着超载、桩端土模量的增大和固结时间的推移,得出最大负摩阻力数值增大,中性点位置下移,桩身最大轴力增大的一致规律。Negative skin friction（NSF） numerical simulation of pile foundation is carried out combined with pile foundation test instance in collapsible loess area. Some significant factors,such as the length of pile,the load on the top,overload,the soil elastic modulus and consolidation time of pile are analyzed. The results indicate： The shorter of the pile, the faster of the settlement caused by the load on the top of pile increase. The location of neutral point move up evidently, downdrag caused by NSF and decreasing trend becomes gently while working load acting upon the pile increase. Maximal NSF absolute value increase, the location of neutral point move down, maximal axis strength increase when the overload and the soil elastic modulus increase during consolidation time lapsed.

关 键 词：湿陷性黄土 桩基 负摩阻力 中性点 数值模拟 

分 类 号：TU4[建筑科学—土工工程]