高填方路堤灾变机理及风险评估

发布时间：2018-04-19 23:35

本文选题：高填方路堤 + 灾变机理　；参考：《重庆交通大学》2015年硕士论文

【摘要】：随着山区交通建设的进一步发展,高填方路堤无论是在数量上还是在高度上都将进一步的提高,高填方路堤将成为路基结构的主要形式。长期以来,由于高填方路基本身设计和施工的复杂性,导致路堤灾害时有发生,同时引起的高填方路堤风险问题普遍存在。因此,对高填方路堤灾变机理及其风险进行分析研究是非常有必要的。本文以高填方路堤灾害为主线,对高填方路堤灾变机理及风险评估理论进行了深入研究。具体内容包括:(1)在收集整理现有文献的基础上,结合高填方路堤病害调查,总结和分析高填方路堤类型,定义了路堤破坏的四种类型:地基滑坡、路基滑塌、路基沉陷及路基裂缝。其中,地基滑坡主要受控于地基条件;路基滑塌主要受控于填筑体强度;路基沉陷和路基裂缝主要受控于堤体填筑质量和地基条件。(2)在分析岩土体的变形和强度特征的基础上,对高填方路堤沉降和失稳机理做了分析研究,指出沉降是岩土体在附加应力作用下孔隙体积变化的结果;失稳是潜在滑裂面的应力屈服所致。各种内外营力的作用导致的高填方路堤应力场、温度场及干湿场的变化是灾害形成的本质原因。(3)在高填方路堤灾害类型及影响因素分析基础上,运用有限元分析软件分析了地基条件、临空条件、填筑条件及水的作用对高填方路堤变形与破坏特征的影响。其中地基条件、填筑压实度和水是高填方路堤灾变的主要影响因素;最大沉降位于填方厚度最大处,最大水平位移均位于堤顶外侧处且具“回缩”现象;不均匀沉降主要受填方厚度和可压缩地基土层厚度控制;圆弧形滑动是高填方路堤失稳破坏的主要形式。(4)以灾害风险理论为研究工具,对高填方路堤灾害风险及风险因素进行分析,指出高填方路堤灾害风险主要是高填方路堤失稳风险,主要风险因素为岩土体力学参数。结合可靠度理论建立了高填方路堤失稳风险评估模型,以失效概率来评价高填方路堤失稳风险,同时,在分析和总结国内外文献资料基础上,对高填方路堤风险评判标准进行分析,给出了高填方路堤失稳风险标准的建议值。
[Abstract]:With the further development of the mountain traffic construction, the high fill embankment will be further improved in both quantity and height, and the high fill embankment will become the main form of the subgrade structure. For a long time, because of the complexity of the design and construction of high embankment, the disaster of embankment occurs frequently, and the risk of high embankment is generally existed at the same time. Therefore, it is necessary to analyze the mechanism and risk of high-fill embankment disaster. In this paper, the disaster mechanism and risk assessment theory of high fill embankment are studied in depth, taking the disaster of high fill embankment as the main line. The concrete contents include: (1) on the basis of collecting and sorting out the existing documents, combining with the investigation of high fill embankment disease, summarizing and analyzing the type of high fill embankment, defining four types of embankment damage: Foundation landslide, subgrade collapse, Subgrade subsidence and subgrade cracks. Among them, the landslide of the foundation is mainly controlled by the condition of the foundation, the collapse of the subgrade is mainly controlled by the strength of the filling body, the settlement of the subgrade and the crack of the subgrade are mainly controlled by the quality of the embankment and the condition of the foundation.) based on the analysis of the deformation and strength characteristics of the rock and soil, The mechanism of settlement and instability of high fill embankment is analyzed. It is pointed out that settlement is the result of pore volume change of rock and soil under additional stress, and instability is caused by stress yield of potential slip surface. The changes of stress field, temperature field and dry and wet field of high fill embankment caused by various internal and external forces are the essential reasons for the formation of disaster. (3) based on the analysis of disaster types and influencing factors of high fill embankment, In this paper, the effects of foundation condition, gob condition, filling condition and water on deformation and failure characteristics of high fill embankment are analyzed by using finite element analysis software. Among them, the foundation condition, the compaction degree of filling and the water are the main influencing factors of the disaster of the high embankment, the maximum settlement is located at the maximum thickness of the embankment, and the maximum horizontal displacement is located at the outside of the top of the embankment and has the phenomenon of "retraction". The uneven settlement is mainly controlled by the thickness of the fill and the thickness of the soil layer of the compressible foundation, and the circular slip is the main form of instability and failure of the embankment with high fill. Based on the analysis of hazard risk and risk factors of high embankment, it is pointed out that the risk of high embankment is mainly the risk of instability of high embankment, and the main risk factor is geophysical parameters. Combined with reliability theory, a risk assessment model for instability of high embankment is established. The failure probability is used to evaluate the risk of instability of high embankment. At the same time, based on the analysis and summary of domestic and foreign literature, The risk evaluation criteria of high embankment are analyzed, and the suggested value of risk criterion for instability of high embankment is given.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.12

【参考文献】