极端降雨条件下小流域淤地坝系连溃风险分析  

Risk Analysis of Check Dam System Under Extreme Rainfall in Small Watershed

作　　者：祖强 陈祖煜 于沭[2] 黄谢平[3] 于坤霞 王志坚[4] 王琳 ZU Qiang;CHEN Zuyu;YU Shu;HUANG Xieping;YU Kunxia;WANG Zhijian;WANG Lin(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xi’an University of Technology,Xi’an 710048;Department of Geotechnical Engineering,China Institute of Water Resources and Hydropower Research,Beijing 100048;Institute of Geotechnical Engineering,College of Civil Engineering,Zhejiang University,Hangzhou 310058;Institute of Soil and Water Conservation Science,Shanxi Agricultural University,Taiyuan 030013)

机构地区：[1]西安理工大学西北旱区生态水利国家重点实验室,西安710048 [2]中国水利水电科学研究院岩土工程研究所,北京100048 [3]浙江大学建筑工程学院岩土工程研究所,杭州310058 [4]山西农业大学水土保持科学研究所,太原030013

出　　处：《水土保持学报》2022年第1期30-37,共8页Journal of Soil and Water Conservation

基　　金：国家自然科学基金项目(51879285,41731289,51909214);2021年山西省水利技术研究推广项目(2021LS016)。

摘　　要：近年来,黄土高原上的淤地坝在减轻水土流失、淤地造田等方面发挥了重要作用。但相较土石坝,淤地坝的防洪标准不高,更容易发生溃坝。淤地坝多以梯级形式分布在若干小流域中,构成了一个复杂的坝系网络,为正确评价溃决风险带来很大的挑战。采用一种基于小流域水文计算和考虑复杂入流条件的淤地坝系连溃风险分析模型及相应的计算程序FT-IWHR,以山西省西廒沟流域淤地坝除险加固工程为实例,在校核工况(洪水重现期为200年)下对现状淤地坝系进行了连溃风险分析。同时在现状坝系和若干年后各坝淤积面达到设计淤积高程这2种工况下对除险加固方案进行了可行性分析。结果表明:现有8#中型坝不满足防洪标准,临界降雨量仅为133 mm;增设宽6 m、高3 m的溢洪道后临界降雨量增至945 mm,在淤积面达到设计淤积高程后临界降雨量降为886 mm,均满足防洪要求;且增设溢洪道能够有效减少淤积面升高带来的风险。研究提出的淤地坝系连溃风险分析方法及实例应用成果对淤地坝系在极端降雨下的防洪风险分析和规划设计具有一定的参考价值。In recent years,check dams on the Loess Plateau have played an important role in mitigating soil erosion and silting land for land reclamation.But compared with earth and rock dams,the flood control standard of check dams is not high,and the dam break is more likely to occur.Check dams are distributed in a number of small basins in the form of stairs,forming a complex dam system network,which brings great challenges for the correct evaluation of the risk of failure.This paper adopted a failure risk analysis model of check dam systems based on hydrological calculations in small watersheds and considered the complex inflow conditions and the corresponding calculation program FT-IWHR.Taking the check dam reinforcement project in the Xi’ao watershed in Shanxi Province as an example,under the checking conditions(the flood return period is 200 years),the current check dam system was analyzed for continuous collapse risk.At the same time,the feasibility analysis of the danger-removing and reinforcement scheme was carried out under the two working conditions of the current check dam system and the siltation surface of each dam reaching the design siltation elevation after a few years.The results showed that the current 8#medium dam did not meet the flood control standards,and the critical rainfall was only 133 mm.The critical rainfall would increase to 945 mm after adding the spillway of 6 m wide and 3 m high,and the critical rainfall would decrease to 886 mm after the siltation surface reached the siltation elevation.both of which could meet the flood control requirements.And the addition of a spillway could effectively reduce the risk caused by the rise of the siltation surface.The risk analysis method and practical application results of check dam system have certain reference value for flood control risk analysis and planning design of check dam system under extreme rainfall.

关 键 词：淤地坝 梯级分布 连续溃坝 风险分析 除险加固 

分 类 号：TV122[水利工程—水文学及水资源]