摘要
超长桩广泛已应用于土木工程各个领域,但黄土地区超长桩的承载性状和变形特性尚不十分清楚,需要进一步研究。通过对郑西铁路客运专线某特大桥的4根超长桩现场测试项目的资料分析,得出了超长桩桩身轴力及侧阻力的变化规律,对超长桩的承载特性有了更为清晰的了解。试验结果表明,在桩顶竖向荷载作用下,桩身轴力随荷载的增加发生了局部调整,砂性土层的桩侧摩阻力具有增强效应,黏性土层的桩侧摩阻力具有退化效应;单桩竖向刚度随桩顶荷载的增加而减小,单桩竖向刚度降低40%~70%。
The vertical static load test is adopted to investigate 4 super-long bored piles in loess, in which the variation of axial force in piles is tested by vibrating wire strain gauge. Hence, the bearing capacity behavior, load transfer mechanism, the lateral friction and end bearing capacity are researched. With the increasing of vertical static load, the results indicate that: (1) shaft force distribution of bored pile is different from that of original cases; and this difference mainly concentrates on top of 1/3 pile length; (2) enhancing effect of static lateral friction and degradation effect of static lateral friction are obtained in sand soil; (3) the vertical static loading can induce decreasing of axial stiffness of single pile; and (4) axial stiffness of single pile reduces about 40 %-70 %.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2010年第1期174-178,共5页
Rock and Soil Mechanics
关键词
高速铁路
超长桩
承载特性
桩侧摩阻力
单桩竖向刚度
high-speed railway
super-long bored pile
bearing capacity behavior
lateral friction
axial stiffness of single pile