上覆土嵌岩桩抗拔受力性状离心模型试验研究
Centrifugal model tests research of uplift behavior of rock-socketed piles overburden soil

上覆土嵌岩桩采用的形式主要为等截面桩和扩底桩，而目前扩底桩相对等截面桩承载力提高机制尚无理论研究，实际工程中现场试验往往限制因素太多，此方面在规范设计中也比较缺乏，对嵌岩桩的相关研究和现行规范不能完全应用于电力行业中。基于此，采用离心模型试验对等截面桩和扩底桩的抗拔承载特性进行研究，分析比较等截面桩和扩底桩在完整岩体中岩体破坏模式的差异，以及在竖向上拔荷载作用过程中的Q-s曲线、桩身轴力分布和桩侧摩阻力曲线。试验成果对我国西部输电线路工程中桩基优化设计具有工程意义和经济价值，能为类似工程提供参考依据。
Overburden rock-socketed pile with enlarged bottom and equal section were mainly used for the foundation of transmission tower in mountainous area of western China. Nevertheless, there is no theoretical research on mechanism of the enhanced bearing capacity of the pile with enlarged bottom. Compared to the pile with equal section, there are too many constraints for the pile with enlarged bottom in field test of practical engineering and few specifications in this aspect. Therefore, the research and current specification of rock-socketed piles can not be entirely applied to the power industry. Based on this, a centrifugal model test is proposed to study the bearing capacity of pile with enlarged bottom and equal section, analyze and compare the failure mode, Q-s curves, distribution of axial force and lateral friction curves of pile with enlarged bottom and equal section in intact rock mass under uplift load. Accurate knowledge of uplift bearing capacity behavior of pile with enlarged bottom and equal section is of great significance to engineering and economy in optimal design of pile foundation in transmission line engineering in western China and it’s also a good reference for similar engineering