岩土力学2023，Vol.44Issue(12)：3339-3348,10.DOI:10.16285/j.rsm.2022.1886
下伏空洞桥梁群桩桩端岩层极限承载力计算方法研究
Calculation method of ultimate bearing capacity for rock layer of pile tip of bridge pile groups with underground karst cave
摘要
Abstract
To explore the bearing mechanism and failure mode for rock layer of pile tip of bridge pile groups with underground karst cave,laboratory model tests of single pile and pile groups with different numbers of piles were carried out.The ultimate bearing capacity and failure modes for rock layer of pile tip of pile groups with different numbers of piles were captured.The failure surface was divided into two parts according to the characteristics of the failure mode for the rock layer with underground karst cave,and a calculation method for ultimate bearing capacity was developed by combining with limit analysis method.The theoretical calculation values match well with the experimental values,which verifies the rationality of the proposed method.Meanwhile,the relationship between the ultimate bearing capacity for the rock layer has been analyzed and it can provide reference for bridge pile foundation construction in karst area.The experimental and theoretical calculation results indicate that:(1)When the rock layer of pile tip of pile groups with underground karst cave is overall destroyed,the whole destroyed body can be regarded as a large pier foundation similar to destroyed body of single pile.(2)When the pile spacing is smaller,the ultimate bearing capacity for the rock layer increases with the increase of the length of the outer envelope line of outer foundation pile.Furthermore,when the length of outer envelope lines are the same,the arrangement of internal foundation piles has no effect on the ultimate bearing capacity for the rock layer.(3)The coefficient of pile group effect increases with increasing the pile spacing,and the critical pile spacing is 5d-6d(d is the pile diameter).关键词
桥梁群桩/空洞地基/极限承载力/极限分析/群桩效应系数Key words
bridge pile group/ground with underground karst cave/ultimate bearing capacity/limit analysis/pile group effect coeffiicient分类
建筑与水利引用本文复制引用
雷勇,陈于斯,谭豪,李鹏甲,刘运思,于艺林..下伏空洞桥梁群桩桩端岩层极限承载力计算方法研究[J].岩土力学,2023,44(12):3339-3348,10.基金项目
国家自然科学基金(No.51878270) （No.51878270）
湖南省自然科学基金(No.2022JJ30253).This work was supported by National Natural Science Foundation of China(51878270)and the Natural Science Foundation of Hunan Province of China(2022JJ30253). （No.2022JJ30253）
