震后泥石流治理工程有效性评价及存在问题分析

汶川8.0级地震及芦山7.0级地震后,针对严重的泥石流灾害,在强震区实施了大量防治工程.通过对地震重灾区92条泥石流沟治理工程实地调查分析,初步建立了基于事前(P)、事中(N)、事后(F)阶段的泥石流防治工程效果评价体系,并利用该评价体系对研究区的泥石流防治工程进行了有效性评价,治理工程效果"良好-优"的占到总数的59...

Effectiveness Evaluation and Problems Analysis of Debris Flow Control Project after Earthquake

After the Wenchuan and Lushan earthquakes,a large number of prevention and control projects have been carried out in the strong earthquake affected area in view of the serious debris flow disaster.Based on the field investigation and analysis of 92 debris flow control projects in the earthquake stricken area,the author initially established the evaluation system of debris flow control project effect based on the stages of beforehand(P),in-process(N)and afterwards(F),and used the evaluation system to evaluate the effectiveness of the debris flow control project in the study area.The"good~excellent"control project effect accounted for 59.78%of the total,most of the prevention and control projects have played a good role in disaster reduction.At present,the main problems existing in the prevention and control engineering are:full silting of the retaining dam,erosion of the abutment and damage of the protective dam,foundation erosion of drainage drainage canal or protective dike,etc.,which affect the prevention and control effect.The reasons for these problems are as follows:the characteristics of debris flow in the aspects of start-up characteristics,flow rate,flushing scale,scouring depth,material source and transformation after the earthquake have changed greatly compared with those before the earthquake.These characteristics of debris flow after the earthquake lead to the generally small calculation results of Engineering design parameters in the existing specifications.Finally,the paper puts forward some preliminary thoughts on the prevention and control of debris flow in the later stage.