北京市门头沟区某公路岩质边坡稳定性分级研究

Stability classification of rock slopes along a highway in Mentougou,Beijing

北京市门头沟区某公路岩质边坡数量多,边坡物理力学性质及其影响因素复杂多变,无法获取每个边坡岩体的物理力学参数,因此,对大量边坡进行力学稳定性分析十分困难。采用层次分析和模糊综合评价方法,根据各种因素对岩质边坡稳定性影响的定性分析,确定了2级4类共9个边坡稳定性影响因子,将边坡的稳定性级别划分为4级,即稳定、基本稳定、较不稳定和不稳定;然后,构建了隶属度矩阵和权重矩阵;最后,对每个边坡的稳定性进行模糊综合评价。分析结果表明,在所研究的113个边坡中,不稳定边坡3个,占总边坡的3%,较不稳定边坡27个,占24%,基本稳定边坡52个,占46%,稳定边坡31个,占27%。因此认为:当边坡数量众多、边界条件模糊、影响因素复杂时,模糊综合评判是比较合适的边坡稳定性分析方法;应用最大隶属度原则时,需根据各种因素对边坡稳定性影响的因果关系,对最大隶属度原则的有效性进行评估,以防出现评判失效。

The rock slopes,along a highway in Mentougou,Beijing,have characteristics as follows:huge a-mounts of 1 1 3 ,complicated influencing factors,large difficulty to gain mechanical parameters of all slopes,so it is hard to investigate the mechanical properties for large member of slopes.Analytic multilayer process and fuzzy comprehensive evaluation are used to classify the slope stability in this paper.Two-layer and four primary influen-cing factors including nine secondary influencing factors are chosen to evaluate the slope stability according to the influencing factors of slope stability.Firstly,the stability classification is divided into 4 grades:stable,basically stable,less unstable,and unstable.Secondly,membership matrix and weight matrix are constructed.Lastly,sta-bility of every slope is classified by the fuzzy comprehensive evaluation.The results indicate that the number of unstable slopes is 3 ,3% of all slopes;the number of less unstable slopes is 27 ,24% of all slopes;the number of basically stable slopes is 52,46% of all slopes;the number of stable slopes is 31 ,27% of all slopes.If the number of slopes is huge,boundary conditions are not clear and influencing factors are complicated,fuzzy comprehensive evaluation is an eligible method.It should be noted that the validity of the maximum subordination principle should be evaluated based on the effect of every factors on slope stability in case the evaluation fails.