摘要
大坝的溃口宽度与土石坝发生溃坝后下游洪水的淹没范围紧密相关,是计算溃坝时最大流量的重要参数。在铁道部科学研究院以及黄河水利委员会溃口宽度计算经验公式中,溃口宽度都与库容、土石坝长度以及坝高有关,只是土石坝长度的幂次方项不相同。在运用以上2个溃口宽度计算公式对7个国内外土石坝溃坝案例进行对比计算后,计算出的溃口宽度相比实际宽度都有较大误差,为探究土石坝长度对洪水溃坝的影响,并使经验公式计算结果更接近真实溃口宽度,对以上7个溃坝案例数据使用Allometricl模型进行拟合,提出溃口宽度计算优化公式。并对另外2个国内溃坝案例进行验算,发现溃口宽度误差均在4.5%以内,表明优化公式比常用经验公式精度高,可为计算土石坝的溃坝最大流量提供依据。再使用DBFL-IWHR模型与传统公式计算下游断面洪水演进情况并进行对比,发现传统公式计算出的下游断面最大流量相比DBFL-IWHR模型较小,同时下游断面最大流量到达时间相比DBFL-IWHR模型较大。
Dams are important structures that provide various benefits,such as hydroelectric power generation,irrigation,and flood control.However,dam failures can lead to catastrophic consequences,causing significant economic and human losses.Therefore,predicting the potential impact of a dam break is crucial for ensuring the safety of people and property downstream.The width of the breach is a critical factor in estimating the flooded area downstream of an earth-rock dam during a dam break.Traditional empirical formulas developed by the Scientific Research Institute of the Ministry of Railways and the Yellow River Water Conservancy Commission are used to estimate the width of the breach,taking into account the storage capacity,length,and height of the dam.However,these formulas have been found to have significant errors when compared to actual breach widths observed in dam break cases at home and abroad.To improve the accuracy of these formulas,this paper uses an allometric model to fit the data from seven dam break cases,resulting in an optimization formula for calculating the width of the breach.The new formula takes into account the length,height,and storage capacity of the dam,as well as the degree of compaction of the soil in the dam body.The optimized formula has been found to have a maximum error of only 4.5%when compared to actual breach widths,indicating that it is more accurate than the traditional empirical formulas.The optimization formula proposed in this study provides a more accurate method for estimating the width of the breach in earth-rock dam breaks,and can be used to improve the accuracy of calculations for maximum flow rate.The results of this study can also have significant implications for dam safety engineering,as well as for the development of effective emergency response plans in the event of a dam break.In addition,the DBFL-IWHR model is used to simulate the downstream flood evolution and compared with the traditional empirical formula.The DBFL-IWHR model is a two-dimensional hydrodynamic model that takes into account the complex interactions between the water flow and the topography of the river channel.The results show that the maximum flow rate calculated by the traditional formula is lower than that of the DBFL-IWHR model,and that the arrival time of the maximum flow rate in the downstream section is delayed compared to that of the DBFL-IWHR model.This highlights the importance of using accurate models in predicting the potential impact of dam breaks on downstream areas.In conclusion,the optimization formula proposed in this study provides a more accurate method for estimating the width of the breach in earth-rock dam breaks,and can be used to improve the accuracy of calculations for maximum flow rate.Furthermore,the use of accurate hydrodynamic models,such as the DBFL-IWHR model,is recommended for simulating the downstream flood evolution and predicting the potential impact of dam breaks.These findings may have significant implications for dam safety engineering,emergency response planning,and the protection of people and property downstream of earth-rock dams.
作者
张修杰
陈明辉
张伟锋
韦未
ZHANG Xiu-jie;CHEN Ming-hui;ZHANG Wei-feng;WEI Wei(South China Agricultural University,College of Hydraulic and Civil Engineering,Guangzhou 510642,Guangdong Province,China;Guangdong Communication Planning and Design Institute Group Co.,Ltd.,Guangzhou 510507,Guangdong Province,China)
出处
《中国农村水利水电》
北大核心
2023年第10期23-29,共7页
China Rural Water and Hydropower
基金
交通运输部规程编制项目《公路越岭隧道水文地质勘察规程》
广东省交通规划设计研究院集团股份有限公司科技创新项目-粤交院[2021]研发YF-015
广东省级大学生科技创新项目(S202110564060)。
