公路边坡地震失稳规模模糊综合统计评估

Fuzzy comprehensive statistical assessment of highway slope seismic instability scale

针对现有边坡地震危险性评估方法对失稳规模很少提及,且常用于危险性评估的模糊综合决策方法主观性较强的问题,开发一种公路边坡地震失稳规模的模糊综合统计评估方法。基于模糊统计原理,以汶川地震震后调查资料中记载的408个失稳公路边坡为样本,将评估方法各指标的取值范围划分为若干区间,在每个区间分别进行模糊统计,并对模糊统计结果进行曲线拟合,以得到各指标对失稳规模的区间隶属度。然后利用模糊综合决策方法,根据观测值判断失稳规模等级。利用所开发的评估方法评估其他45处公路边坡地震失稳规模,得到的评估结果的准确率为88.6%,表明该方法是有效的。由于没有其他矫正过程,且边坡样本数量相对较少,该方法的准确率尚有提升空间。

In view of that the existing method of slope seismicity hazard assessment rarely mentioned instability scale, and that fuzzy comprehensive decision-making method used frequently in hazard assessment has strong subjectivity,the authors of this paper have developed a fuzzy comprehensive statistical method for evaluation of highway slope seismic instability scale. Based on the traditional fuzzy statistical principle, 408 unstable roadway slopes recorded in Post-earthquake investigation data of Wenchuan earthquake were taken as samples,the authors divided the value range for each index of this assessment method into several intervals and conducted fuzzy statistics on every intervals,then the fuzzy statistical results were curve fitted to obtain the interval membership degree of each index. Next,using the fuzzy comprehensive decision-making model,instability scale was determined according to the observed value. At last,the developed assessment method was used to assess the seismic instability scale of other 45 highway slopes. The accuracy of the evaluation results obtained by this method is 88. 6%,indicating that the method is effective. Because the method has no other correction process,and that the number of slope samples is relatively small,there is still room for improving the accuracy of this method.