摘要
为考虑岩溶区基桩嵌岩段岩层与顶板的整体承载效应及溶洞形状对桩端极限承载力的影响,在嵌岩桩桩端极限破坏模式研究的基础上,首先根据桩端极限破坏线与溶洞的位置关系,确定了溶洞发生破坏时的临界状态;其次,结合桩端岩层极限状态下的传力机制,分析了岩溶区嵌岩桩桩端极限破坏模式。然后,通过建立极坐标系,给出了溶洞发生冲切破坏、冒顶破坏的限定条件,并推导了不同破坏模式下岩溶区嵌岩桩桩端极限承载力的计算公式。最后,用试验数据与工程实例对本文理论进行验算,验算结果表明:理论计算结果与试验现象及工程实例结果较为吻合,可为岩溶区嵌岩桩桩端极限承载力的计算提供一些参考。
The approach for calculating the ultimate bearing capacity at the tip of rock-socketed pile in karst areas is proposed considering the coupled bearing effects of rock of socketed part and cavity roof, as well as the influence of the shape of cavity. Firstly, based on the researches on the ultimate failure mechanism at the tip of rock-socketed pile, the critical failure conditions of the cavity are determined in accordance with the position relationship between the cavity and the ultimate failure line of pile tip. Secondly, the failure modes at the tip of rock socketed pile in karst areas are analyzed considering the force-transferring mechanism of the rock at the tip of pile under the critical condition. Then, the punching and collapse failure conditions of the cavity roof are given in the polar coordinate system. Moreover, the formula for the ultimate bearing capacity at the tip of rock-socketed pile in karst areas under different failure modes are deduced. Finally, the results of theoretical calculation agree well with those of tests and engineering examples, which can provide guidance for calculating the ultimate beating capacity at the tip of rock-socketed pile in karst areas.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2017年第6期1123-1129,共7页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51278187
51408060)
关键词
岩溶区
嵌岩桩
桩端
整体承载效应
极限承载力
karst area
rock-socketed pile
tip of pile
coupled bearing effect
ultimate bearing capacity
