红黏土基底高填方边坡变形及稳定性研究

发布时间：2018-05-07 02:43

本文选题：高填方边坡 + 红黏土地基　；参考：《中国矿业大学》2017年硕士论文

【摘要】：随着我国西南地区基础设施建设的快速发展,机场、公路、铁路等项目的建设带来的高填方边坡日益增多,加上西南地区地质条件极为复杂,因此对高填方边坡变形和稳定性的研究变得至关重要,不仅关系到工程建设能否顺利完成,而且直接影响建设场地日后的正常使用。西南地区广泛分布红黏土,红黏土作为一种特殊性地基土,对上覆填方边坡的变形和稳定性有重要影响,因此对于红黏土作为边坡基底的研究也显得至关重要。本文以云南安宁地付罐区高填方边坡为研究对象,综合多种方法研究该红黏土基底高填方边坡的变形和稳定性,对同类型的工程有一定的指导意义。论文主要工作内容如下:(1)根据收集的勘察、设计和施工资料,掌握并概述研究区的地形地貌、地质构造、地层结构、水文地质等,同时也分析了施工技术参数和变形特征。(2)根据收集的勘察资料,概述了研究区岩土体的结构特性及其物理力学性质。通过分析三个阶段的室内土工试验数据,结合原位测试手段,研究分析了填方施工前后,下覆软弱土层红黏土的物理力学性质的变化,同时通过surfer软件依据收集的钻孔资料分析得到了填土和红黏土的分布特征。(3)利用GEO-SLOPE软件SIGMA模块和有限差分软件FLAC3D分别从二维和三维对填方边坡的施工过程进行模拟计算,分析填方边坡的位移变化和拉应力分布。然后根据数值模拟结果,分析地付罐区裂缝产生的原因,及其与基底红黏土的相关性。(4)根据工后坡体地表监测数据,结合类似工程变形,分析和预测坡体的变形趋势,并且通过两者来对比数值模拟的结果,从而验证数值模拟的有效性。(5)利用SLIDE软件基于简化BISHOP法对四个典型剖面进行一般工况和地震工况的稳定性计算,同时为了分析裂缝形成原因及对罐区东侧整个坡体的稳定性的影响,假定滑动面后缘位置为裂缝区域,再次利用SLIDE软件进行稳定性计算。然后利用FLAC3D软件基于强度折减法对边坡进行折减计算,得到相应的安全系数,并与SLIDE软件计算结果比较。最后采用《公路工程抗震规范》中的计算公式验证SLIDE软件计算的地震工况下最危险剖面的稳定性。(6)结合多种方法对高填方边坡的分析计算结果,综合评估填方边坡的稳定性。同时根据之前的工作,研究分析红黏土基底对整个填方边坡变形及稳定性的影响,以及与坡体裂缝产生的关系。
[Abstract]:With the rapid development of infrastructure construction in southwest China, the construction of airports, highways, railways and other projects has resulted in an increasing number of high fill slopes, and the geological conditions in southwest China are extremely complex. Therefore, the study of deformation and stability of high fill slope becomes very important, which not only relates to the successful completion of engineering construction, but also directly affects the normal use of construction site in the future. Red clay is widely distributed in southwest China. As a special foundation soil, red clay has an important effect on the deformation and stability of overlying fill slope, so it is very important to study red clay as the base of slope. In this paper, the deformation and stability of the high fill slope of the red clay foundation are studied by taking the high fill slope of Anning Tiefu area in Yunnan Province as the research object, which has certain guiding significance for the same type of project. The main work of the paper is as follows: (1) based on the collected survey, design and construction data, the topographical features, geological structure, stratigraphic structure, hydrogeology and so on of the study area are mastered and summarized. At the same time, the construction technical parameters and deformation characteristics are analyzed. (2) based on the survey data collected, the structural characteristics and physical and mechanical properties of rock and soil in the study area are summarized. The physical and mechanical properties of red clay overlying soft soil layer before and after filling construction were studied and analyzed by analyzing the data of three stages of indoor geotechnical test and in situ testing. At the same time, based on the analysis of borehole data collected by surfer software, the distribution characteristics of fill and red clay are obtained. The construction process of filling slope is simulated by GEO-SLOPE software SIGMA module and finite difference software FLAC3D from 2D and 3D, respectively. The displacement variation and tensile stress distribution of fill slope are analyzed. Then, according to the results of numerical simulation, the causes of cracks and their correlation with red clay are analyzed, and the deformation trend of slope is analyzed and forecasted according to the surface monitoring data of post-construction slope and similar engineering deformation. The results of numerical simulation are compared with each other to verify the validity of numerical simulation. (5) using SLIDE software to calculate the stability of four typical sections under general and seismic conditions based on simplified BISHOP method. At the same time, in order to analyze the cause of crack formation and the influence on the stability of the whole slope body in the east side of the tank area, it is assumed that the position of the back edge of the sliding surface is the crack area, and the stability calculation is carried out again by using SLIDE software. Then the slope is reduced by FLAC3D software based on the strength reduction method, and the corresponding safety factor is obtained, and the calculated results are compared with those of the SLIDE software. Finally, the stability of the most dangerous section under seismic condition calculated by SLIDE software is verified by the calculation formula in "Code for earthquake Resistance of Highway Engineering". The stability of the slope is evaluated synthetically by combining the results of analysis and calculation of high fill slope with various methods. At the same time, according to the previous work, the influence of red clay base on the deformation and stability of the whole fill slope and the relationship between the red clay base and the cracks in the slope body are studied and analyzed.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU446

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