考虑降雨入渗影响的软岩边坡过程稳定性研究

发布时间：2018-12-11 10:59

【摘要】：岩质边坡在高速公路建设中分布广泛，其稳定性对公路工程的建设和投资有着非常重要的影响，由于自然环境和人类活动的影响，边坡失稳现象时有发生，给社会和经济带来了巨大损失。软岩作为一种特殊的岩石，具有可塑性、易扰动性等工程特性，使得软岩边坡的稳定性更加难以控制。因而研究降雨条件下软岩边坡的开挖过程及支护过程中边坡稳定性的变化规律具有非常重要的理论意义与实际价值。本文在前人的研究成果基础上，以湖南汝郴高速公路软岩边坡为工程背景，开展了降雨条件下软岩边坡开挖及支护过程中稳定性的变化规律研究，主要研究内容如下： 1.通过对降雨条件下软岩边坡的稳定性影响因素分析，表明：在降雨量一定时，降雨历时t对软岩边坡安全性的影响大于降雨强度q；岩土体的物理力学参数中，滑动面内摩擦角对软岩边坡的安全性影响最大，粘聚力c次之，重度的影响最小； 2.通过有限元软件geo-studio模拟考虑降雨入渗的软岩边坡开挖过程及支护过程，并将开挖前后软岩边坡滑动面及支护前后软岩边坡滑动面进行对比，其结果表明：降雨入渗降低了软岩边坡的稳定性；开挖过程中，软岩边坡的安全性先升高后降低；边开挖边支护过程中，软岩边坡的开挖变形得到了有效控制； 3.将软岩边坡所处状态划分为三个等级，选取15个评价指标建立了考虑降雨入渗的软岩边坡过程稳定性评价指标体系，结合层次分析法和模糊综合评判法构建了软岩边坡过程稳定性模糊评价模型； 4.采用Visual Basic语言编制了考虑降雨入渗的软岩边坡过程稳定性评价系统，初步实现了软岩边坡过程稳定性评价的智能化和快速化，并以实例验证了该评价系统的有效性和可行性。
[Abstract]:Rock slope is widely distributed in highway construction, and its stability has a very important impact on the construction and investment of highway engineering. Due to the influence of natural environment and human activities, slope instability occurs from time to time. Great losses have been brought to society and the economy. Soft rock, as a special rock, has the engineering characteristics of plasticity and disturbance, which makes the stability of soft rock slope more difficult to control. Therefore, it is of great theoretical significance and practical value to study the excavation process of soft rock slope and the variation law of slope stability in the process of supporting under rainfall condition. Based on the previous research results and taking the soft rock slope of Ru-Chen Expressway in Hunan Province as the engineering background, the variation law of the stability of the soft rock slope during excavation and support under rainfall conditions is studied in this paper. The main contents are as follows: 1. By analyzing the factors influencing the stability of soft rock slope under rainfall condition, it is shown that the influence of rainfall duration t on the safety of soft rock slope is greater than that of rainfall intensity when rainfall is constant. Among the physical and mechanical parameters of rock and soil, the internal friction angle of sliding surface has the greatest influence on the safety of soft rock slope, the cohesion C is the second, and the influence of heavy degree is the least; 2. The excavation process and support process of soft rock slope considering rainfall infiltration were simulated by finite element software geo-studio, and the sliding surface of soft rock slope before and after excavation was compared with that of soft rock slope before and after excavation. The results show that rainfall infiltration reduces the stability of soft rock slope. In the process of excavation, the safety of soft rock slope first increases and then decreases; in the process of excavation and support, the deformation of soft rock slope is effectively controlled; 3. The state of soft rock slope is divided into three grades, and the evaluation index system of process stability of soft rock slope considering rainfall infiltration is established by selecting 15 evaluation indexes. The fuzzy evaluation model of the process stability of soft rock slope is constructed by combining the analytic hierarchy process (AHP) with the fuzzy comprehensive evaluation method. 4. The process stability evaluation system of soft rock slope considering rainfall infiltration is developed by using Visual Basic language. The intelligent and rapid evaluation of soft rock slope process stability is preliminarily realized, and the effectiveness and feasibility of the evaluation system are verified by an example.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU457

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