【作者】 王家成；

【导师】 王乐华； 李建林；

【作者基本信息】 三峡大学 ， 水工结构工程， 2011， 硕士

【摘要】 随着三峡工程的修建,水库蓄水,三峡库区适合于人类生活和居住的一、二级阶地被淹没,库区移民建设用地的严重不足,不得不在条件差的复杂地质体,甚至滑坡等灾害堆积体开挖动土,形成众多高切坡。这些高切坡可能导致库岸岩土体发生失稳甚至造成大规模的滑坡灾害。因此非常有必要对高切坡进行稳定性分析及治理防护。岩土体的抗剪强度参数是高切坡稳定性分析的前提,参数取值的合理性直接影响高切坡稳定分析结果的准确性。巴东县新城区库岸公路高切坡及城区建筑高切坡开挖后大多为碎石土,碎石土是一种不同于土和岩体的高度非均质不连续体。针对碎石土普遍含有碎石的显著特点,加之碎石土颗粒粗大,粗细粒配比和试验尺寸对抗剪强度特征有一定的影响,为此选取三峡库区移民新城巴东高切坡碎石土为研究对象,主要采用室内大型直剪试验方法对其抗剪强度参数进行了研究。1.总结和分析了的研究现状,指出了目前碎石土抗剪强度参数取值需要解决的问题。在此基础上,提出了本文的主要工作。2.从自然地理条件、地质构造、地形地貌、地质灾害分布及危险性影响四个方面介绍了巴东县新城区的地质概况。巴东高切坡地质条件具有典型性,包括地段的典型性与构成高切坡组成成分的典型性。在地质条件分析的基础上,阐释了选择巴东县新城区高切破碎石土作为研究对象的针对性和有效性。3.介绍了大型直剪仪的主要组成、主要技术指标、结构原理及操作过程;制定了试验方案,针对巴东不同地区某典型高切坡的碎石土,在不同含水率和不同颗粒级配情况下进行多组大型直剪试验,着重分析研究了不同含水率和不同颗粒级配情况下的碎石土大型直剪试验结果。结合室内试验成果,讨论了大型直剪仪本身存在的缺陷、地质代表性、法向应力的大小范围、试验数量、含水率、土的级配对高切坡碎石土抗剪强度参数的影响,研究发现这些因素是c,φ值的重要随机变量。4.选取库区边坡--焦家湾高切坡工程,结合室内试验抗剪强度参数和已有的工程地质资料,采用室内大型直剪试验与参数反演相结合的取值方法选取工程实际合适的参数,对焦家湾高切坡进行了稳定性分析。证明了室内试验+参数反演获取抗剪强度参数的有效性。更多还原

【Abstract】 With the construction of the Three Gorges Project, the impoundment of Three Gorges reservoir, as the one or two terraces in Three Gorges reservoir area which are suitable for human life and living were flooded, the construction land of reservoir resettlement are serious shortage, people had to excavate on the complex geology of poor conditions, even the landslides and other accumulation body of disasters, forming a large number of high cut slopes. They may lead to instability of rock and soil reservoir banks and even cause a large-scale landslide hazard. Therefore it is necessity to carry the stability analysis and treatment on high cut slope. Rock and soil shear strength parameters is the premise of analysis of the high cut slope stability,the rationality of parameter values directly affect the accuracy of the results of the analysis of high cut slope stability. The high cut slope of reservoir-bank road and city buildings are mostly the gravel soil after excavation. Gravel soil is a kind of highly inhomogeneous and noncontiguous material which is different from soil and rock mass, being widely distributed over the Three Gorges Reservoir bank slopes. For the gravel soil have a significant feature is that it generally contains gravel, combined with the large grain size, coarse-grained content and specimen size have much effect on the gravel soil strength behavior. As a result selected three gorges immigrants new town Badong high cut slopes gravel soils as the research object,the indoors large scale direct shear apparatus is used to test direct shear strength behavior of the gravel soil .1. This paper summarizes and analyzes the research status of gravel soils, and pointed out that the current shear strength parameter selection problems need to be solved. On this basis, the paper put forward the main job.2. From natural and geographical conditions, geological structures, landform, distribution of geological disasters and dangerous effects four aspects introduced geological survey of Badong. Badong high cut slopes geological conditions including the area typicality and structure of high cut slopes component typicality. On the basis of geological condition analysis, explained the pertinence and effectiveness of select Badong high cut slope gravel soils as the research object.3. Introducing the main components,main technical indices ,structural principle and the operating process of the large size direct shear apparatus. According to the test scheme, selected three different soil samples of Badong high cut slopes, many groups of large direct shear tests has been taken under different water content and different gradation. Combining with laboratory test results , discussing the influence of high cut slope gravel soil shear strength parameters by large-scale direct shear apparatus inherent defects,geological representation, the size range of normal stress imposing during the test,the number of the test,water content of sample and particle size distribution of sample. We found that these factors are the important random variables of c,φvalues after study.4. Select reservoir slope-JiaoJiaWan high cut slope, combined with high cut slopes engineering laboratory test shear strength parameters and existing engineering geological material, combined the indoor large direct shear tests and parameter inversion analysis two methods to select suitable parameters of engineering practice . JiaoJiaWan high cut slope stability is analyzed. Proof the effectiveness of two methods combined-indoor large shear test with parameter inversion analysis to obtain shear strength parameters.更多还原