郑石高速公路强风化花岗岩路堤稳定性研究

发布时间：2018-02-27 06:32

本文关键词： 强风化花岗岩边坡稳定三轴剪切试验有限元分析现场监测路堤变形特性　出处：《长安大学》2014年硕士论文　论文类型：学位论文

【摘要】：高速公路对路基稳定性有较高的要求。目前我国对花岗岩风化料的研究还远远不能解决设计和施工中出现的问题，因此对强风化花岗岩的风化机理、风化特征以及风化料的路用特性进行系统的研究，对于高等级公路的建设具有重要的意义。对强风化花岗岩进行了大型压缩试验、三轴剪切试验（CU），得到了强风化花岗岩在CU条件下的摩尔强度包线。从该强度包线可以看出强风化花岗岩的粘聚力是增大到一定值之后开始减小，而内摩擦角存在持续减小的现象。利用大型三轴仪对风化岩进行试验发现风化岩并不具备浸水丧失强度的特性，，性能较为稳定，适宜作为路基填料。利用有限元方法对强风化花岗岩高边坡的稳定性进行了分析，确定了边坡坡度较优设计形式，分析了降雨对边坡安全状况的影响。有限元模拟结果表明降雨对强风化花岗岩填筑的高填方路堤的影响较大，需要采取一定防护措施。通过有限元和现场监测对风化花岗岩路堤的沉降特性进行了分析；采用FLAC3D软件与编制的邓肯-张本构模型对强风化花岗岩风化料路堤的稳定性进行了分析。数值计算的结果显示：对于平坦的弱风化岩地基上填筑的风化花岗岩高填方路堤整体沉降量变化较小，满足设计要求；斜坡上的高填方路堤路肩处沉降相对于中央带、行车带位置处的沉降要小，数值计算的结果与实测结果基本符合。
[Abstract]:The highway has higher requirements for the stability of roadbed. At present, the research on granite weathering material in China is far from solving the problems in design and construction, so the weathering mechanism of strongly weathered granite can not be solved. The systematic study of weathering characteristics and road characteristics of weathered materials is of great significance to the construction of high-grade highways. A large scale compression test of strongly weathered granite was carried out. In triaxial shear test, the molar strength envelope of strongly weathered granite under CU condition is obtained. From this strength envelope, it can be seen that the cohesive force of strongly weathered granite increases to a certain value and begins to decrease. However, the internal friction angle is decreasing continuously. The test of weathered rock with large triaxial instrument shows that the weathered rock does not possess the characteristics of water immersion and loss of strength, and its performance is relatively stable, so it is suitable for subgrade filling. The stability of high slope of strongly weathered granite is analyzed by finite element method, and the optimum design form of slope is determined. The effect of rainfall on slope safety is analyzed. The finite element simulation results show that rainfall has a great influence on the high fill embankment filled with strongly weathered granite, and some protective measures should be taken. The settlement characteristics of weathered granite embankment are analyzed by finite element method and field monitoring. The stability of weathering material embankment of strongly weathered granite is analyzed by using the FLAC3D software and the Duncan Zhang Ben model. The numerical results show that the weathered granite filled on the flat weak weathered rock foundation is high. The overall settlement of embankment has little change. The settlement at the shoulder of the high fill embankment on the slope is smaller than that at the central zone, and the settlement at the location of the driving belt is small, and the numerical results are in good agreement with the measured results.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.12;U412.366

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