小秦岭金矿区7·23蒿岔峪泥石流成灾模式及启示  

Hazard mode of the 7·23 mine debris flow in the Xiaoqinling gold mine area

作　　者：徐友宁[1] 陈华清[1] 张江华[1] 乔冈[1] 杨敏[1] 

机构地区：[1]中国地质调查局西安地质调查中心/国土资源部陕西潼关金矿区地质环境野外科学观测基地/国土资源部黄土地质灾害重点实验室,陕西西安710054

出　　处：《地质通报》2015年第11期2001-2008,共8页Geological Bulletin of China

基　　金：国家自然科学基金项目(批准号:40872208);中国地质调查局项目(编号:1212010741003)

摘　　要：矿山泥石流是山地矿山最主要、危害最严重的地质灾害类型。小秦岭金矿区是中国矿渣型泥石流灾害及其隐患的典型矿区,研究其成灾模式对于科学防治具有重要的指导作用。通过2010年7月23日泥石流沟的勘查、泥石流泥位与颗粒级配测量、降雨参数分析等,表明短历时、高强度大暴雨(142.9mm/6.42h、雨强52.6mm/h、4.6mm/10min)是7·23泥石流形成的直接激发因素。沟道内挤占行洪通道的人工残存坡地及选矿尾渣为泥石流提供了66.7%的物源。泥石流堆积扇粗颗粒(粒径≥2mm)含量高达92.4%,泥石流最大流速为9.61m/s,最大流量455.05m^3/s,推算泥石流历时112.5s,系一次性、中型规模的水石流,但却造成了8死4伤的灾难。其致灾模式是强暴雨的片蚀作用导致沟源高陡斜坡上的残坡积物形成梳状浅层滑坡群,下滑至沟底,在坡面迅速汇集的山洪作用下转化成沟谷稀性泥石流。沿程通过冲蚀、侧蚀、底蚀作用,不断加大了泥石流规模,沟口残缺的浆砌水泥挡墙堵溃放大了泥石流的灾害效应。固渣、排水、疏浚沟道是治理堵溃型矿山泥石流的有效方法。Frequent mining activities and discharge of waste residues in the Xiaoqinling gold mine area have led to serious hidden dangers of slag-debris flow. A heavy downpour hit and aroused a debris flow in Haocha Gully on July 23, 2010, which caused death of eight persons and ruin of houses and storages. Profile research on initiating and circulation areas gave the parameters of turning radius, discharge section, water level, bed slope and denudation degree. Grain size distribution of eluvium and residues was determined via samples in accumulation areas. Velocity and quantity of debris flow in different sections were calculated, and gully denudation and deposit volume were comparatively studied so as to estimate peak flow as well as theoretical and actual rainfalls. Based on the data obtained, the authors inverted the motivating factors and structure of the debris flow so as to provide basis for the early warning system of slag-debris flow.

关 键 词：矿山泥石流 堵溃型泥石流 成灾模式 小秦岭金矿区 

分 类 号：P694[天文地球—地质学] P642.23