泥石流拦挡坝总坝高设定及坝后淤积计算  

Design of Total Dam Height and Calculation of Siltation behind Debris Flow Dam

作　　者：刘兴荣[1] 周自强[1] 董耀刚[1] 张国信[1] 魏万鸿[1] 李霞[1] LIU Xing-rong;ZHOU Zi-qiang;DONG Yao-gang;ZHANG Guo-xin;WEI Wan-hong;LI Xia(Geological Hazards Prevention Institute, Gansu Academy of Sciences, Lanzhou 730000, China)

机构地区：[1]甘肃省科学院地质自然灾害防治研究所,兰州730000

出　　处：《科学技术与工程》2021年第29期12500-12506,共7页Science Technology and Engineering

基　　金：第二次青藏高原综合科学考察(2019QZKK0903);甘肃省科技计划(20YF3FA006);甘肃省青年科技基金(1308RJYA093);甘肃科学院科技产业化项目(CY08);甘肃省科学院应用研究与开发项目(2018JK-19)。

摘　　要：泥石流沟道治理中拦挡坝总坝高的设定和坝后淤积率的计算涉及治理工程的安全和经济效益,是一个无法回避的难点。以武都区已治理的23条沟道(共布设112道拦挡坝)作为研究对象进行比较分析,采用直线相关的回归方程对经验公式进行优化。结果表明:泥石流沟道运行9~11 a后,武都区43%的泥石流治理沟道总库容淤积和单坝淤积不足50%,属于过度治理;优化后的拦挡坝总高度计算公式既考虑了泥石流沟道治理的安全,又考虑了治理效益的最大化,更符合设计要求;推导的坝后回淤比降计算公式与原沟床建立了线性关系,便于设计人员应用,其计算结果约为治理前沟床比降的0.49~0.61倍,在前人研究的区间内,具有科学性和实用性。以上研究为武都区泥石流拦挡坝设计、创新及管理提供了可靠依据。There has been an unavoidable engineering issue for years in the construction of debris flow control project,in which engineers struggled to reach a compromise between the safe operation of a debris flow retaining dam and its investment budget,and it mostly referred to determination of the total dam height of a retaining dam and a proper siltation rate in dam-back.112 retaining dams in 23 debris flow gullies in Wudu District,Longnan City,Gansu province,China were selected for evaluation of their operating situation.Proposals were made to optimize empirical formulas in the design of debris flow control project by linear regression method.Comments are listed as follows.After 9~11 a of operation,43%of debris flow control projects in Wudu District had accumulated geo-materials less than 50%of their total storage capacity and the same there were happening for single retaining dams,strongly suggesting idle design or excessive design extensively existed in these debris flow control projects.An optimized formula proposed for properly calculating the total height of a retaining dam not only concerns the operating safety,but also maximizes the economic exploitation of debris flow control project,satisfying design requirements.The formula was established based on a linear relationship between dam-back silting gradients and original gully beds,convenient for designers to apply.By this formula,it obtained an optimized gradient of gully bed about 0.49~0.61 of original gradient of gully floor before engineered control.This index interval was derived scientifically and practically,in line with antecedent research conclusion.This research provides a reliable basis for design,innovation and management of debris flow retaining dam in Wudu District.

关 键 词：泥石流 拦挡坝总坝高 坝后淤积率 线性关系 设计 

分 类 号：P694[天文地球—地质学] X43[环境科学与工程—灾害防治]