基于岩体质量的溶洞顶板安全厚度确定方法  

Determination Method of Safe Thickness of Karst Cave Roof Based on Rock Mass Quality

作　　者：郜江俊 肖豹 蒋春桂 杨小龙 GAO Jiangjun;XIAO Bao;JIANG Chungui;YANG Xiaolong(China Construction Fifth Engineering Bureau Co.,Ltd.,Changsha,Hunan 414000,China)

机构地区：[1]中国建筑第五工程局有限公司,湖南长沙414000

出　　处：《施工技术（中英文）》2022年第19期13-18,22,共7页Construction Technology

基　　金：“十三五”国家重点研发计划:超高层建筑工程施工安全关键技术研究与示范(2016YFC0802000);2021年南京市建设行业科技计划项目:溶洞型桩基设计与溶腔整治施工技术研究(Ks2162);2022年南京市建设行业科技计划项目:混凝土-木组合结构智能建造及智慧安装技术研究与应用(Ks2150)。

摘　　要：岩溶地区进行桩基础施工时,常因溶洞上方岩层厚度不够而被压碎,引起工程安全问题。为保证桩基-岩层-溶洞的整体稳定性,以泰康(南京)国际医学中心项目为背景,开展基于岩体质量的溶洞顶板安全厚度确定方法研究。引入岩体质量等级参数,并结合极限分析法、弹性力学薄板理论,得出以下结论:溶洞顶板冲切或剪切破坏模式下,当岩体质量较差时,各桩基不同直径条件下的厚径比结果基本满足规范要求;当岩体质量较好时,厚径比取值有一定降低;顶板弯拉破坏模式下,溶洞顶板安全厚度取值变化情况并不明显;给出了3种不同破坏模式下的溶洞顶板安全厚度建议值。During pile foundation construction in karst area, the rock stratum above the karst cave is often crushed as a consequence of insufficient thickness, resulting in engineering accidents. In order to ensure the overall stability of pile foundation-rock stratum-cave, based on the project of Taikang(Nanjing) International Medical Center, the method of determining the safe thickness of cave roof based on rock mass quality is studied. By introducing rock mass quality grade parameters, combined with limit analysis method and elastic thin plate theory, the following conclusions are drawn: under the punching or shearing failure mode of karst cave roof, when the rock mass quality is poor, the thickness-diameter ratio results under the diameter of each pile foundation basically meet the specified requirement. When the quality of rock mass is good, the value of thickness-diameter ratio decreases to some extent. Under the bending failure mode of the roof, the change of safe thickness of karst cave roof is not obvious. And the recommended values of safe thickness of karst cave roof under different failure modes and three failure modes are given.

关 键 词：桩基础 岩溶地区 顶板 安全厚度 理论分析 

分 类 号：TU753.3[建筑科学—建筑技术科学]