炭质泥岩—土分层填筑路堤稳定性研究
发布时间：2018-11-03 07:50
【摘要】：炭质泥岩广泛分布于我国西南部地区,由于其具有水理性强、易风化、强度低、变形大等特点,在以往的公路建设中常作为不良填料予以废弃,但是随着我国高速公路建设的快速发展,很多地区适宜的填料极为匮乏,从经济和环保两方面考虑,利用炭质泥岩进行路堤填筑势在必行,如何保证施工过程中以及工程建成后的工程安全便成为公路建设者们最关心的问题之一。因此,有必要开展炭质泥岩-土分层填筑路堤稳定性研究,以期为炭质泥岩-土分层填筑公路路堤的设计与施工提供可靠依据。本文以广西六寨至河池高速公路为工程依托,针对炭质泥岩-土分层填筑路堤稳定性的影响因素,从多方面对路堤稳定性进行了较为深入的研究。主要研究内容如下：(1)崩解炭质泥岩抗剪强度参数研究。通过炭质泥岩直接剪切试验可知：含水率是影响炭质泥岩粘聚力和内摩擦角的主要影响因素,内摩擦角是影响炭质泥岩路堤填筑材料的抗剪强度的主控因素。(2)基于极限平衡条分法的分层填筑路堤稳定性研究。基于瑞典圆弧法和简化Bishop法极限平衡条分法进行相关推导,得到可以适用于不同材料的分层填筑路堤的瑞典圆弧法和简化Bishop法计算方法。通过对比分析可知：分层填筑路堤稳定计算方法较采用极限平衡法计算软件数值模拟所得的安全系数更小,其在工程应用更安全,经济效益更佳,对实际工程的设计和施工具有较强的指导性意义。(3)填筑材料强度参数变化对路堤稳定性影响。通过缩小一定比例的室内路堤模型试验对炭质泥岩-土分层填筑路堤在降雨条件下的材料强度变化进行研究。由室内路堤模型试验和数值模拟可知：降雨开始时,路堤稳定性的安全系数迅速减小；降雨稳定时,路堤稳定性的安全系数降幅不大；随着降雨的持续,路堤稳定性的安全系数又迅速减小,且减小的幅度大于降雨开始阶段。同时,整个试验过程中时,粉质粘土和炭质泥岩的重度、粘聚力以及内摩擦角都呈现下降趋势。
[Abstract]:Carbonaceous mudstone is widely distributed in the southwest of China. Because of its characteristics of strong water rationality, easy weathering, low strength and large deformation, it is often abandoned as a bad filler in highway construction in the past. However, with the rapid development of highway construction in China, the suitable fillers in many areas are extremely scarce. Considering both economic and environmental protection, it is imperative to use carbonaceous mudstone for embankment filling. How to ensure the safety in the construction process and after the completion of the project has become one of the most concerned issues for highway builders. Therefore, it is necessary to study the stability of carbonaceous mudstone-soil layered embankment in order to provide reliable basis for the design and construction of carbonaceous mudstone-soil stratified embankment. Based on the Liuchai-Hechi Expressway in Guangxi, the stability of embankment is studied from many aspects, aiming at the influencing factors of the stability of the embankment constructed by stratification of carbonaceous mudstone and soil. The main contents are as follows: (1) the shear strength parameters of carbonaceous mudstone disintegrating. Through the direct shear test of carbonaceous mudstone, it can be seen that water content is the main factor affecting cohesion and internal friction angle of carbonaceous mudstone. The angle of internal friction is the main factor that affects the shear strength of carbonaceous mudstone embankment. (2) the stability of layered embankment is studied based on the limit equilibrium strip method. Based on the Swedish arc method and simplified Bishop method, the calculation methods of Swedish arc method and simplified Bishop method are obtained, which can be used for layered embankment construction of different materials. Through comparison and analysis, it can be seen that the stability calculation method of layered embankment is smaller than that of numerical simulation software by using limit equilibrium method, and its application in engineering is safer and its economic benefit is better. It has a strong guiding significance for the design and construction of practical engineering. (3) the change of the strength parameters of the filling material affects the stability of the embankment. The change of material strength of carbonaceous mudstone-soil layered embankment under rainfall was studied by reducing a certain proportion of indoor embankment model test. From the indoor embankment model test and numerical simulation, it can be seen that the safety factor of embankment stability decreases rapidly at the beginning of rainfall, and the safety factor of embankment stability decreases slightly when rainfall is stable. With the continuous rainfall, the safety factor of embankment stability decreases rapidly, and the decrease is larger than that at the beginning of rainfall. At the same time, the density, cohesion and angle of internal friction of silty clay and carbonaceous mudstone decreased during the whole experiment.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.12
本文编号：2307165
[Abstract]:Carbonaceous mudstone is widely distributed in the southwest of China. Because of its characteristics of strong water rationality, easy weathering, low strength and large deformation, it is often abandoned as a bad filler in highway construction in the past. However, with the rapid development of highway construction in China, the suitable fillers in many areas are extremely scarce. Considering both economic and environmental protection, it is imperative to use carbonaceous mudstone for embankment filling. How to ensure the safety in the construction process and after the completion of the project has become one of the most concerned issues for highway builders. Therefore, it is necessary to study the stability of carbonaceous mudstone-soil layered embankment in order to provide reliable basis for the design and construction of carbonaceous mudstone-soil stratified embankment. Based on the Liuchai-Hechi Expressway in Guangxi, the stability of embankment is studied from many aspects, aiming at the influencing factors of the stability of the embankment constructed by stratification of carbonaceous mudstone and soil. The main contents are as follows: (1) the shear strength parameters of carbonaceous mudstone disintegrating. Through the direct shear test of carbonaceous mudstone, it can be seen that water content is the main factor affecting cohesion and internal friction angle of carbonaceous mudstone. The angle of internal friction is the main factor that affects the shear strength of carbonaceous mudstone embankment. (2) the stability of layered embankment is studied based on the limit equilibrium strip method. Based on the Swedish arc method and simplified Bishop method, the calculation methods of Swedish arc method and simplified Bishop method are obtained, which can be used for layered embankment construction of different materials. Through comparison and analysis, it can be seen that the stability calculation method of layered embankment is smaller than that of numerical simulation software by using limit equilibrium method, and its application in engineering is safer and its economic benefit is better. It has a strong guiding significance for the design and construction of practical engineering. (3) the change of the strength parameters of the filling material affects the stability of the embankment. The change of material strength of carbonaceous mudstone-soil layered embankment under rainfall was studied by reducing a certain proportion of indoor embankment model test. From the indoor embankment model test and numerical simulation, it can be seen that the safety factor of embankment stability decreases rapidly at the beginning of rainfall, and the safety factor of embankment stability decreases slightly when rainfall is stable. With the continuous rainfall, the safety factor of embankment stability decreases rapidly, and the decrease is larger than that at the beginning of rainfall. At the same time, the density, cohesion and angle of internal friction of silty clay and carbonaceous mudstone decreased during the whole experiment.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.12
【参考文献】
相关期刊论文 前1条
1 李广居;瑞典法分析边坡稳定时的最危险圆弧问题[J];水利水电技术;1989年04期
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