泥石流岩土防治工程治理效果分析与评价——以四川汶川卧龙幸福沟为例

Analysis and Evaluation of the Treatment Effect of the Geotechnical Engineering of Debris Flow:Case of Xingfu Gully in Wolong

为了研究泥石流岩土防治工程在泥石流的防灾减灾中所起的作用,以2019年“8.20”泥石流为背景,结合现场考察,对四川汶川县卧龙幸福沟泥石流岩土防治工程的治理效果进行分析和评价。根据研究区防治工程的分布,将拦挡工程因子和排导工程因子作为2项一级指标,同时考虑防治工程运行情况,筛选出与治理效果相关的9项二级指标,其中拦挡工程的评价指标包括工程运行情况、容重削减率、堆积物粒径比、流量削减率、回淤坡度比、拦蓄泥沙比,排导工程的评价指标包括工程运行情况、沟床纵坡比、断面参数比,采用层次分析法确定权重进行效果综合评价,认为幸福沟泥石流岩土防治工程的治理效果为中等,与现场的调研结果一致,验证了评价体系的合理性和该方法的可行性。

In order to research the effect of geotechnical engineering in the prevention and mitigation of debris flow.Based on the“8.20”debris flow in 2019,combined with the field investigation,the treatment effect of geotechnical engineering of debris flow of Xingfu gully in Wolong is analyzed and evaluated.According to the distribution of geotechnical engineering in the study area,it can be divided into two first-class indices:check dams and drainage projects.At the same time,considering the operation of engineering,nine secondary indices related to the treatment effect of engineering are selected.Among them,the evaluation indices of the check dams include the operation of the check dams,the reduction rate of the bulk density,the particles ratio,the reduction rate of the peak flow rate,the ratio of gradient of intercepted sediments and the ratio of sediment retention.The evaluation indices of the drainage projects include the operation of the drainage projects,the ratio of the gradient and the ratio of section factor coefficient.The analytic hierarchy process is used to determine the weight for the comprehensive evaluation of the effect.It is considered that the treatment effect of geotechnical engineering of debris flow of Xingfu gully is moderate,which is consistent with the field investigation results,and verifies the rationality of the evaluation system and the feasibility of this method.