自然类比法在黄土路堑边坡设计中的应用研究

Study on Analogism Used in Highway Cutting Loess Slope Design

根据目前黄土地区公路路堑边坡设计仍以自然类比法为主要设计依据的现状,以陕西黄土自然边坡为调查研究对象,提出极限状态坡的定义及鉴别标志。测量了79个陕北至关中黄土极限状态坡,并将其按地形地貌、粒度组成和抗剪强度特征等的差异,划分为3个地段进行对数线性模型回归和不同置信度下的统计分析,给出3个地段不同置信度下坡高与坡度的相关关系,将自然类比法从各工点的定性分析转化为系统的定量分析。结果与目前已修建的黄土路堑边坡对比,认为量化的自然类比法可以作为黄土路堑边坡设计的一个系统方法。

Based on the reality that nature analogism is the present-used way to design the highway cutting loess slope, nature loess slope was researched deeply in Shaanxi Province. The concept of limit state slope was defined with four criteria of field identification. The 79 limit state slopes were investigated. The research area was divided into 3 zones from south to north on their topography, soil properties and shear strength. For the main sections of limit state slopes, logarithmic liner regression model of the correlation between height and gradient of downgrade was built up. Statistic parameters under different degree of confidence were achieved in the three zones respectively. Qualitative analysis of analogism was successfully transformed to systematic quantitative analysis. Compared the statistic result with that of the excavated loess slopes on highways, it is conformed that quantified analogism is a reliable method for loess slope design.