泥石流拦挡坝工程服役性能特征分析——以甘肃省陇南市武都区为例

Analysis of service performance characteristics of debris flow check dams:A case study in Wudu District,Longnan City,Gansu Province

拦挡坝是泥石流防治工程中最重要的措施之一,其防灾减灾能力在服役期间随着泥石流多次冲出逐渐降低,需开展拦挡坝服役性能特征分析。以甘肃省陇南市武都区泥石流拦挡坝为研究对象,对区内15条沟、55座拦挡坝服役性能进行了现场调查,从有效性和安全性两方面遴选了库容淤积比、坝肩边坡稳定程度、排水孔堵塞程度、坝体损毁度、坝基损毁度、坝肩损毁度、安全性等7个评价因子,采用层次分析法和模糊综合评价法建立了拦挡坝单坝服役性和拦挡坝单沟综合服役性的评价模型,将服役性能等级划分为优、良、中等、差等4个等级。评价结果表明:拦挡坝单坝服役性等级“差”占34.5%;拦挡坝单沟综合服役性等级“差”占33.3%,评价结果与现场考察相符。研究成果为拦挡坝服役效果及服役寿命预测提供了可借鉴的依据。

Check dams play a pivotal role in debris flow prevention and control engineering.However,their disaster prevention and mitigation capacity gradually decrease over service time due to repeated debris flow impacts.The study was carried out in 15 ditches and 55 check dams within Wudu District,Longnan City,Gansu Province.Seven key evaluation factors were selected for effectiveness and safety:reservoir siltation ratio,slope stability,drainage hole blockage,dam body damage,dam foundation damage,dam shoulder damage,and safety.The evaluation model of the serviceability of the indivusual dam and the comprehensive serviceability of the single trench of the barrage was established by using hierarchical analysis and fuzzy comprehensive evaluation method,and the serviceability was divided into four grades:excellent,good,medium and poor.The evaluation results show that the serviceability rating of individual dams is predominately"poor",accounting for 34.5%.Similarly,the collective serviceability rating of single trench dams for debris flow is predominately"poor",at 33.3%.The results of the evaluation are consistent with the fieldwork observations,providing a valuable reference for predicting the service performance and service life of barrage dams.