穿越充填溶洞时单桩沉降计算方法研究  

Study on calculation method for settlement of a single pile crossing filled karst cave

作　　者：乔胜石 张乾青[1,2] 邢宇铖 张凯 王志远 QIAO Shengshi;ZHANG Qianqing;XING Yucheng;ZHANG Kai;WANG Zhiyuan(Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,China;Research Institute of New Materials and Intelligent Equipment,Shandong University,Dezhou 251100,China;Shandong Luqiao Group Co.Ltd.,Jinan 250021,China)

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061 [2]山东大学齐河新材料与智能装备研究院,山东德州251100 [3]山东省路桥集团有限公司,山东济南250021

出　　处：《中南大学学报（自然科学版）》2024年第10期3909-3920,共12页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52278358);山东省泰山学者青年专家任务(tsqn202103163);山东大学杰出中青年学者计划项目(2024)。

摘　　要：采用圆孔扩张理论提出竖向受荷桩周地层对充填溶洞的水平和竖向作用力计算方法,采用Mindlin解建立溶洞段应力增量计算方法,基于桩-土(岩)界面、桩-溶洞界面的Boxlucas1荷载传递模型提出考虑地层-溶洞-桩共同作用的穿越充填溶洞型单桩沉降迭代计算方法。通过案例分析验证本文计算方法的合理性。根据参数分析结果,研究溶洞与桩顶的距离、溶洞半径、溶洞充填物剪切强度、桩径、桩长等对单桩承载特性的影响规律。研究结果表明:本文建立的计算方法可用于分析单桩穿越单个或多个充填溶洞时的承载特性;充填溶洞距离桩端越远、半径越小、充填物剪切强度越强,单桩承载力越大。Based on the theory of round hole expansion,the calculation method of horizontal and vertical force of stratum on filling karst cave caused by the vertically loaded single pile was proposed.The calculation method was established to predict the stress increment in karst cave section by using the Mindlin's solution.Based on Boxlucas1 load transfer models of pile-soil or rock interface and pile-karst cave interface,an iterative calculation method was proposed to predict the settlement of single pile crossing filled karst cave considering the interaction of stratum,karst cave and pile.The rationality of the present calculation method was verified by using the case analysis.Furthermore,the influence of the distance between karst cave and pile top,karst cave radius,karst cave filling,pile diameter and pile length on the bearing characteristics of single pile was studied.The results show that the present method is suitable for the analysis on the settlement of a single pile crossing a single or multiple filled caves.The further the filled cavity is from the pile tip,the smaller its radius,and the greater the shear strength of the filling material,the higher the bearing capacity of the single pile.

关 键 词：岩溶区 圆孔扩张理论 MINDLIN解 Boxlucas1荷载传递模型 沉降 

分 类 号：TU473.1[建筑科学—结构工程]