地震地质灾害防治工程运行效果评价:以汶川震区平武县魏坝滑坡为例

Operating State Assessment of the Geohazard Prevention and Control Projects in Wenchuan Earthquake Region:A Case Study of Weiba Landslide in Pingwu County

2008年"5·12"汶川地震诱发了数以万计的崩塌、滑坡、泥石流等地质灾害,造成众多人员伤亡和财产损失。汶川地震后,地震灾区危害性大的滑坡多采用截排水沟、挡土墙、抗滑桩、坡面减载和坡脚反压等措施进行了治理,总体防治效果较好,但仍存在一些问题。通过现场调查,结合地震扰动区地质灾害特点,提出了地震地质灾害防治工程运行效果评价的指标体系,包括地质灾害本体因子、防治工程技术因子和社会影响因子3个一级评价指标和12个二级评价指标,并建议将防治效果(R)划分为4个等级:良好(R≥0.85)、较好(0.70≤R<0.85)、一般(0.6≤R<0.70)、差(过于保守或失败,R<0.6)。以汶川震区平武县魏坝滑坡为典型案例,采用层次分析法,建立了地震扰动区滑坡防治工程防治效果评价模型,计算获得魏坝滑坡防治效果R值为0.63,总体防治效果一般,与实际情况相符。

The Wenchuan Ms 8.0 earthquake happened on May 12,2008,resulted in tens of thousands of geo-hazards,such as collapse,landslide,debris flow,and brought a great threat to the safety of human life and property.After the Wenchuan earthquake,the Chinese government has carried out geohazard control project in the disaster area,adopting the construction of water drain,retaining wall,slope anti-slide pile,load shedding and toe back pressure.Although the geohazard prevention project has achieved good control effect in general, there are still some problems in the geohazard prevention and control project in the earthquake region.Through field investigation,based on analyzing the present technique and evaluation methods related to geohazards,an evaluation system for geohazard prevention and control projects has been established for the earthquake disturbed zone.According to the evaluation system,it is believed that the prevention effect evaluation system should in-clude 3 first-level evaluation factors and 12 second-level ones.A comprehensive evaluation model was estab-lished for the effect of the prevention and control projects based on the AHP （analytic hierarchy process）method. It divided the prevention and control efficiency （R）into 4 grades：best （R≥0.85 ）,good （0.70≤R〈0.85 ）,common （0.6≤R〈0.70）and bad （too conservative or failure,R〈0.6）.On this basis,a comprehensive eval-uation was made on Weiba landslide control effect,Pingwu County,and the result show that the control effect is common,which is consistent with the actual situation.