降雨入渗下非饱和土填方路基的渗流特性与稳定性研究

发布时间：2018-08-05 19:23

【摘要】：由于降雨入渗极易导致填方路基的失稳甚至滑坡,因此对降雨条件下非饱和土填方路基的渗流及稳定性变化进行研究有相当重要的意义。本文在系统归纳前人对降雨下的边坡稳定性研究和分析的成果基础上,结合某一在运行的实际高速公路作为工程实例背景,从而针对降雨入渗下非饱和土填方路基的稳定性问题展开探讨。作了如下工作:(1)对非饱和土的力学特性进行了系统性论述。包括非饱和土的各相组成、有效应力、基质吸力、应力状态变量、非饱和土的强度理论与变形理论、基质吸力与抗剪强度的关系以及基质吸力变化引起的应变等诸多方面。(2)对降雨入渗下的填方路基渗流场问题进行了数值模拟分析。通过填方路基模型的建立以及对降雨后土体渗流场的变化规律进行模拟,本文分析了路基渗流场在降雨强度、持续时间和类型三大因素下的影响。并且还研究分析了公路路基的渗流场在渗透系数等因素变化时的影响情况。(3)降雨条件下土体的位移变化分析。通过数值方法,模拟出填方路基在降雨渗流作用下位移的分布情况与发展规律。(4)考虑降雨入渗对填方路基稳定性的影响。分析时把有限元强度折减法拓展应用于非饱和土,求出路基的安全系数,得出了相应情况下安全系数的变化规律。(5)通过分析各种降雨因素对路基和边坡带来的影响,并对降雨后填方路基的渗流规律和边坡稳定性的分析结果进行归纳和总结,以期指导工程实际。
[Abstract]:As rainfall infiltration can easily lead to instability of embankment and even landslide, it is of great significance to study the seepage and stability of unsaturated soil embankment under rainfall conditions. In this paper, based on the research and analysis of slope stability under rainfall, a practical expressway is used as an engineering example. The stability of unsaturated soil embankment under rainfall infiltration is discussed. The main works are as follows: (1) the mechanical properties of unsaturated soil are systematically discussed. Including the phase composition of unsaturated soil, effective stress, matrix suction, stress state variables, strength theory and deformation theory of unsaturated soil, The relationship between matrix suction and shear strength and the strain caused by the change of matrix suction. (2) the seepage field of embankment under rainfall infiltration is numerically simulated. Through the establishment of embankment model and the simulation of soil seepage field after rainfall, the influence of seepage field on rainfall intensity, duration and type is analyzed in this paper. The influence of seepage field of highway roadbed on the change of seepage coefficient and other factors is also studied. (3) the change of soil displacement under rainfall condition. By means of numerical method, the distribution and development of the displacement of embankment under rainfall seepage are simulated. (4) the influence of rainfall infiltration on the stability of embankment is considered. In the analysis, the finite element strength reduction method is extended to unsaturated soil, and the safety coefficient of subgrade is obtained. (5) the influence of various rainfall factors on subgrade and slope is analyzed. The seepage law of embankment after rainfall and the analysis results of slope stability are summarized and summarized in order to guide the engineering practice.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：U416.1

【参考文献】