考虑大型弃渣场的泥石流灾害综合防治研究

Research on comprehensive prevention and control of debris flows disaster considering large slag dump

针对天然沟道中布置大型弃渣场的泥石流灾害防治问题,以金沙江上游旭龙水电站茂顶河泥石流沟为例,探讨天然沟道中大型弃渣场阻断下的泥石流灾害防范治理体系构建。从泥石流的形成条件、泥石流洪峰流量和泥石流规模入手,提出了“上拦+中停+下排”的综合治理方案,并基于OpenLISEM软件反演不同工况下泥石流运动-堆积演变规律,综合评估泥石流防治工程的合理性,形成了天然沟道中布置大型弃渣场的泥石流灾害防治方案。结果表明:空库条件下,拦淤坝排导槽进口底板高程以下库容可以拦截100 a一遇泥石流;初始满库洪水条件下,若发生100 a一遇和200 a一遇的泥石流事件,部分稀性泥石流和洪水混合体将进入排导槽内。研究成果可为天然沟道大型弃渣场阻断下的泥石流防治提供技术支撑。

Aiming at the prevention and control of debris flow disasters for the layout of large slag dump on natural channel,the study took the debris flow channel in Maoding River of Xulong Hydropower Station in the upper reaches of Jinsha River as an example,to discuss the construction of debris flow disaster prevention and control system under the blocking of large slag dump on natural channel.The comprehensive control scheme of"upper block plus middle stop plus lower discharge"was put forward based on the formation conditions,peak flow and scale of debris flow.Based on OpenLISEM software,the law of debris flow motion-accumulation evolution under different working conditions was reversed,and the rationality of debris flow prevention and control project was comprehensively evaluated.Thus,the prevention and control scheme of debris flow disaster under the blocking of large-scale spoil fields was formed.The results showed that under the condition of empty reservoir,the storage capacity below the bottom floor of drainage channel inlet of the silting dam can meet the requirements of intercepting the debris flow event once in 100 years.Under the condition of initial full reservoir flood,if the debris flow event occurs once in 100 years and once in 200 years,some dilute debris flow and flood mixture will enter the drainage channel.The research results can provide a technical support for the prevention and control of debris flows under the blocking of large slag dump on natural channel.