干湿循环对长沙高速典型填料影响及路堤边坡稳定性分析

发布时间：2018-03-11 00:01

本文选题：干湿循环　切入点：红砂岩填料　出处：《长沙理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：路堤土在干湿循环作用下产生一定程度的软化,其抗变形能力和强度均有所下降,容易诱发边坡失稳等工程问题。本文基于水分迁移理论,实地跟踪观测了长沙高速路堤内部土体含水率,选定红砂岩填料和粉质粘土两种水敏感性较强的路堤填料开展室内试验研究。结合室内试验数据(强度参数和压缩参数),使用ABAQUS软件对长沙高速路堤边坡进行稳定性分析,得到了以下成果:(1)通过高密度电法对长沙高速典型路堤填料的含水率跟踪观测,得出长沙高速红砂岩填料含水率的年度最大干湿差幅为10.82%,粉质粘土含水率的年度最大干湿差幅为7.53%。(2)对长沙高速的典型的红砂岩填料和粉质粘土进行室内干湿循环模拟的剪切试验和压缩试验,得到随着干湿循环次数的增加粉质粘土和红砂岩填料的强度参数和压缩参数均随之减小,衰减速率先快后慢,逐渐趋于稳定。粉质粘土在干湿循环作用的影响下粘聚力衰减幅度约为57%,内摩擦角衰减幅度约为36%;红砂岩填料在干湿循环作用的影响下粘聚力衰减幅度约为35%,内摩擦角衰减约为22%。(3)路堤边坡的稳定系数均随干湿循环次数的增多而减小,稳定系数随边坡高度增大而减小。历经四次干湿循环,长沙高速K11+480处红砂岩填料路堤边坡稳定系数衰减约21%,长沙高速K5+940处粉质粘土路堤边坡稳定系数衰减约17%。红砂岩填料路堤边坡比粉质粘土路堤边坡受干湿循环影响引发的稳定性衰减更强烈。回归分析了有限元模拟得到的长沙高速路堤边坡稳定系数,拟合出了长沙高速红砂岩填料和粉质粘土路堤边坡的稳定劣化系数公式。
[Abstract]:The embankment soil softens to a certain extent under the action of dry and wet circulation, and its deformation resistance and strength decrease, which can easily induce slope instability and other engineering problems. This paper is based on the theory of water migration. The soil moisture content in Changsha expressway embankment was observed and tracked in the field. Two kinds of embankment fillers with strong water sensitivity, red sandstone filler and silty clay, were selected to carry out indoor test study. Combined with indoor test data (strength parameter and compression parameter), ABAQUS software was used to analyze the stability of Changsha expressway embankment slope. The following results are obtained: 1) tracking and observing the moisture content of typical embankment fillers in Changsha Expressway by high-density electrical method. The results show that the annual maximum dry and wet difference range of water content of Changsha high speed red sandstone filler is 10.82 and that of silty clay moisture content is 7.53. 2) the typical red sandstone packing and silty clay of Changsha high speed are subjected to indoor dry and wet circulation. Simulated shear and compression tests, The results show that the strength parameters and compression parameters of silty clay and red sandstone fillers decrease with the increase of dry-wet cycle times, and the attenuation rate is first fast and then slow. The cohesion attenuation amplitude of silty clay is about 57 and the attenuation range of internal friction angle is about 36 under the influence of dry and wet cycle, and the attenuation range of cohesive force of red sandstone filler under the influence of dry and wet cycle is about 35%, and that of red sandstone filler is about 35%, and the attenuation range of internal friction angle is about 36% under the influence of dry and wet cycle. The coefficient of stability of embankment slope decreases with the increase of dry and wet cycles. The coefficient of stability decreases with the increase of slope height. The stability coefficient of red sandstone fill embankment slope in Changsha high speed K11 480 is about 21 and that of silty clay embankment slope in Changsha high speed K5940 is about 17. The red sandstone fill embankment slope is subjected to dry and wet circulation compared with silty clay embankment slope. The stability attenuation caused by the influence is stronger. The stability coefficient of Changsha highway embankment slope obtained by finite element analysis is analyzed by regression analysis. The formula of stability deterioration coefficient of Changsha high speed red sandstone filler and silty clay embankment slope is fitted.
【学位授予单位】：长沙理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.1

【相似文献】