降雨入渗下黄土高边坡失稳因素的敏感程度及回归分析

黄土高边坡的稳定性评价是重要的工程问题.采用改进的灰色关联评价方法对黄土高边坡稳定性的敏感程度进行评价,评价中考虑了9个主要影响因素:天然重度、内摩擦角、粘聚力、饱和渗透系数、体积含水率、降雨强度、降雨持时、坡高、坡角.计算结果表明:土体粘聚力和内摩擦角对黄土高边坡稳定性影响最为敏感且权重相当;降雨强度是诱发黄土高边坡失稳的重要因素,权重值达11.3%.边坡的安全系数可表示为坡高和坡角的线性函数,即Fs=αβ+bh+c,其中a,b,c为c,φ,γ,θ,ks,R,T的函数.由此可知对于陇西黄土其单级边坡的临界高度介于11 m和18 m之间,直立高度极限值为4.5 m.

Sensitivity and Regression Analysis of Instable Factors of High Slope of Loess under Rainfall Infiltration

An analysis is made of the sensitivity of the instable factors on the high slopes of loess,including precipitation condition,physical and mechanical parameters,geometric shape of the slope and the stability of residual soil slope.They are studied by an improved grey correlation method.The results of calculation show that the physical and mechanical parameters are dominant and that,the impacts of cohesion and the angle of internal friction on the slopes are the most sensitive and their weights are approximate.The precipitation intensity is an important inducing factor which leads to slope failures and its weight was 11.3%.The purpose of multiple linear regression analysis by means of the software Origin is to get two excellently fitting regression equations,concerned with geometric shape of the solpe and the safety factor and with the physical and mechanical parameters of the earth and the safety factor.And when the safety factor is certain,the height and the angle of high slope of loess are in the linear relation.