甘肃陇南市武都区小水沟泥石流治理防治工程

2008年5.12汶川特大地震对甘肃省陇南市造成了严重危害。震后次生地质灾害对陇南市城镇村庄、交通和人民群众生命财产安全造成严重威胁。武都区蒲池乡小水沟震后产生了大量的崩塌、滑塌堆积体,一旦遭遇暴雨,极易发生泥石流灾害,直接危及小水沟沟口左岸九年制义务学校一座及沟口两岸居民,因此治理该泥石流沟是十分必要的。通过对当地暴雨特征、地层岩性、地质构造、泥石流固体物质源及形成的踏勘,针对该泥石流具有危险度高,流量大的特点,执行全面规划、重点治理的设计思路,采取了防护、生物工程相结合的综合防治措施。拦挡工程为有效发挥工程泻洪、拦渣、调节、固床、稳坡和控制固体物质补给量,预防沟道下切及沟壑发展,减少泥石流对下游村庄危害,起到了积极作用;生物工程的主要作用是稳固堤前砂土、减缓水石流流速、减小水石流对护堤的直接冲蚀和破坏、保障堤内居民生命财产安全和耕地的正常使用、增大植被覆盖率,绿化环境等。

Engineering treatment for debris flow at Xiaoshui Gully,in Puchi Town,Wudu District,Longnan City

Wenchuan Earthquake on May 12,2008 sever hit Longnan City of Gansu Province and brought serious damages there.The secondary geo-hazards by quake have adversely impacted the communications and buildings in the towns and villages,threatening the safety of the lives and properties of the local residents.Lots of piles appeared after collapses and landfalls by the quake,at Xiaoshuigou,in Puchi Town,Wudu District.The piles are prone to become debris flow when hit by storm,which would directly destroy a primary school and the residential houses at the mouth of the gully.Thus,taking engineering measures to prevent the potential debris is not only necessary but very urgent.Based on the knowledge of storms in the area and field survey of the lithology,geological structure,solid resources of debris flow,the paper proposed a comprehensive treatment plan for debris flow at Xiaoshui Gully,in which there was an overall planning with considerations of key points and engineering measures,like blocking bar and biological engineering projects.Blocking bars could be very effective to effuse flood,block sediments,adjust flows,stable the bed,control the solid mass recharge,and prevent the ditch from developing deep.Biological engineering could stable the sand and soil in front of the dam,retard the flow,and reduce the erosion of the embankment by the flow,which could be protective to the residents and farm lands and improve the coverage of vegetation.