岩土力学2025，Vol.46Issue(6)：1839-1850,12.DOI:10.16285/j.rsm.2024.1050
下伏溶洞的高嵌岩比基桩承载特性模型试验
Model tests on bearing characteristics of pile with high rock-socketed ratio above an underlying karst cave
摘要
Abstract
For piles above underlying karst caves,the ratio of rock-socketed depth to cave roof thickness(rock-socketed ratio)can be high in certain projects.To study the influence of karst cave roof thickness on the vertical bearing characteristics of piles with high rock-socketed ratio,load tests were conducted on model piles with a rock-socketed ratio of 0.5,while the cave roof thickness was gradually increased from one to five times the pile diameter.Based on the test results,an analysis model for the ultimate bearing capacity of the pile was proposed,and a calculation formula was derived using the limit equilibrium principle.The results show that:(1)The failure mode of karst cave roof is trumpet-shaped punching failure,and the dimensionless fitting function for the fracture surface can reasonably predict the range of roof fracture.(2)The load-displacement curve at the pile top exhibits a steep change type,with an approximately linear relationship before the steep change point.(3)As the roof thickness increases,the ultimate bearing capacity of the pile increases nonlinearly,and the proportion of pile tip resistance supporting the upper load rises from 35.4%to 72.4%.(4)The relative error between the ultimate bearing capacity calculated by the proposed method and the test value ranges from-12.8%to 12.1%,indicating the method's good rationality.关键词
嵌岩桩/下伏溶洞/顶板厚度/竖向承载特性/模型试验Key words
rock-socketed pile/underlying karst cave/cave roof thickness/vertical bearing characteristics/model test分类
建筑与水利引用本文复制引用
杨柏,覃超,张银海,王威,肖世国..下伏溶洞的高嵌岩比基桩承载特性模型试验[J].岩土力学,2025,46(6):1839-1850,12.基金项目
广西自然科学基金(No.2024GXNSFBA010011) （No.2024GXNSFBA010011）
广西高校中青年教师科研基础能力提升项目(No.2024KY0212) （No.2024KY0212）
国家自然科学基金(No.51578466).This work was supported by the Natural Science Foundation of Guangxi(2024GXNSFBA010011),the Guangxi Young and Middle-aged Teachers'Basic Scientific Research Ability Promotion Project(2024KY0212)and the National Natural Science Foundation of China(51578466). （No.51578466）
