【作者】 籍长志；

【导师】 胡卸文；

【作者基本信息】 西南交通大学 ， 防灾减灾工程及防护工程， 2010， 硕士

【摘要】 岩溶地貌在我国分布广泛,给岩溶地区建筑基础的安全稳定性造成极大的影响。随着基础设施建设的不断发展,基础底部岩溶洞穴垮塌导致结构物破坏已成为岩溶地区主要地质问题。深圳地铁线在勘察中发现在高架桥桥桩基下存在大量的溶洞和裂隙,设计者通过综合考虑,将部分高架桥桩基作用在溶洞顶板上。因此,基桩下溶洞顶板稳定性成为控制桥基安全的关键地质问题。论文以深圳地铁岩溶洞穴勘察和病害处理为背景,以工程实际为依据,以目前常见解决岩溶洞穴塌陷方法为基础,通过建立溶洞失稳模型和有岩石顶板的封闭型溶洞稳定性进行计算,分析影响封闭型溶洞顶板稳定性的因素,并对基础下底部溶洞的地基承载力的确定进行定量计算。首先,讨论溶洞失稳的机理,以岩石力学理论为基础,对桩基和溶洞相互作用系统进行简化得出模型。在此基础上,采用传统定量计算方法对岩溶溶洞顶板稳定性进行验算。其次,运用数值模拟分析软件FLAC,对高架桥桩基和溶洞相互作用系统进行数值模拟。并将数值模拟的结果与前面所做的理论计算结果相比较。最后,采用理论计算和数值模拟相结合的方法,分析影响溶洞稳定性的因素。通过分析总结,得出影响溶洞稳定性的敏感因素。更多还原

【Abstract】 Karst distributes widely in our country, it plays a vital influence on the security and stability of the building foundation in the Karst region. With the development of infrastructure in our country, the destructions of building caused by collapse in the based bottom of the cave in Karst region are facing the main geological problem, the Karst problem.This paper is based on actual engineering example—The grade separation bridge in the subway of Shenzhen. Because of the influence of cavern and cranny underground, the pile foundation of the bridge could not be constructed normally. The designer had to put the pile foundation on the cavern roof. Therefore, the stability assessment of cave engineering geological conditions become the main geological problem.Based on the Shenzhen Metro cave investigation and disease treatment and the related typically Karst caves engineering project, based on the current common methods solving cave collapse, this paper establishes a cave subsiding model, calculates and analyzes the stability of closed roof cave, then analyzes the factors that influence the stability of roof in the closed roof cave, this paper quantitatively calculates the bearing capacity of foundation soil in the bottom of the cave basis.Firstly, this paper studies the reasons of the subsiding of cavern and predigests the interactional system between the pile and the cavern to a simple model. Based on the simple model, this paper analyzes the stability of the cavern roof with traditional calculation.Secondly, this paper simulates the interactional system between the pile and the cavern with FLAC3D. Then, the paper compares the result of numerical simulation with the result of traditional calculation what has been draw before, and analyzes the stability of cavern.Lastly, with both the numerical simulation and traditional calculation, this paper analyzes the influence factor of the stability of cavern, and then it analyzes the impressionable factor what influence the stability of cavern by compare with other factors.更多还原