【作者】 刘毅；

【导师】 程谦恭；

【作者基本信息】 西南交通大学 ， 地质工程， 2008， 硕士

【摘要】 本文以郑西客运专线函谷关隧道出口明洞段黄土临时开挖边坡为研究对象,通过对黄土特性的系统论述和施工现场边坡失稳实例的调查,阐明了研究区的工程地质条件,提出了现场边坡失稳破坏模型。在此基础上,通过数值分析计算,进行了黄土临时开挖边坡稳定性及土钉支护的研究分析。通过查阅大量国内外文献资料,总结了国内外边坡稳定性及土钉支护的研究现状及进展,概括了目前常用的边坡稳定性分析方法以及土钉支护作用机理。对黄土的物理力学性质进行了论述,并重点阐述了黄土的垂直节理特性。在阐明研究区工程地质条件的基础上,通过对施工现场边坡滑塌特征的分析,分析了现场边坡失稳的原因,建立了现场边坡失稳的地质模型。根据现场边坡失稳的地质模型,借鉴目前国内铁路、公路行业规范中对黄土边坡开挖以及边坡土钉支护所提出的设计要求,建立了11种数值分析的基本类型。以数值分析计算(FLAC)为手段,对多种工况条件下的边坡开挖及土钉支护性状进行了分析研究。讨论了黄土临时开挖边坡位移变化规律及土钉轴向拉应力分布规律。确定了在研究区黄土边坡开挖时合理的坡形、坡比,以及适宜的土钉支护参数。综合分析,认为影响黄土开挖边坡稳定性的关键因素为:黄土本身的物理力学性质,边坡形状,边坡开挖的深度,边坡顶部垂直节理的位置、竖向延伸深度,支护方式等。更多还原

【Abstract】 In this thesis, a field cutting loess slope was studied, which is located in the open cut segment of Han Guguan tunnel exit of Zheng-xi railway Line for passenger traffic. By the analysis systematically for the loess characteristics and the survey for the construction site slope failure examples, the engineering geologic condition of the field was illustrated, and the local unstable failure model was proposed. Based on the numerical analysis computation, the stability and its soil nailing investigation for the field cutting loess slope was carried out.Based on the domestic and foreign literature and data, the status and development of the investigation of the slope stability and soil nailing supporting were summarized, and the universal analysis methods of slope stability and the mechanism of soil nailing supporting at present were generalized, and to discuss in detail the physical mechanics properties of loess, especially for the joint properties of loess.On the basis of the engineering geologic condition of the field, the collapse feature and cause of the cutting slope were analyzed in detail, and the geologic failure model of the cutting slope was established.According to the geologic failure model of the cutting slope, and the design specifications referred to the codes of railway and highway for the loess cutting slope and its soil nailing supporting , the numerical analysis models were proposed. By the numerical simulation analysis method of Flac, the characteristics of the loess cutting slope and its soil nailing supporting, the displacement changing law of the cutting slope and the tensile stress distributing law of the soil nailing were analyzed, the cutting reasonable slope shape, ratio of the loess cutting slope, and the well parameters of the soil nailing supporting were determined.Based on the, to analyze the cutting slope displacement and deformation of soil nailing axial stress changes in the law , receive the slope excavation reasonable slope shape, slope excavation and reasonable than the soil nailing parameters, in the loess areas.In brief, the critical influence factor of the loess cutting slope stability were as follows: the physical mechanics properties of loess, slope shape, excavation depth, joint position, joint unloading depth, supporting ways and so on.更多还原