摘要
震后低频泥石流发生概率增加、泥石流规模增大,导致拦挡坝阻灾能力变化,进而影响泥石流的危险性.但鲜有研究揭示拦挡坝对泥石流危险性的影响.同时,针对以形成条件为危险性评价指标的传统危险性评价方法无法度量泥石流的破坏力及强度等问题,提出增加泥石流动力学参数作为危险性评价指标,并采用改进的熵值法评估泥石流危险性.通过计算不同重现期下锄头沟泥石流的动力参数、拦挡坝稳定系数.定量分析拦挡坝与泥石流危险性之间的控制关系.结果表明:增加动力特征参数的泥石流危险性评价方法能考虑其动力破坏、泥石流强度作用,结合改进的熵值法能够获取较为科学、合理的评价结果;若拦挡措施安全稳定,由于停淤作用使坝后冲出量减少,使100~10年一遇泥石流危险性降低12.27%~43.75%不等.考虑拦挡坝抗灾能力进行泥石流危险性评价,能有效对防灾减灾决策、土地规划利用等资源的合理调配提供指导.
The debris flow hazard was more serious with the increase of occurrence probability of low-frequency debris flow after the earthquake.Resulting in the damage of retaining dam and reduction of its capabilities in disaster prevention and reduction.But few studies payed attention to the influence of retaining dam on debris flow hazard.Moreover,disaster-pregnant factors were usually used as the index of debris flow hazard,but the result of hazard evaluation could not completely reflect the destructive power and intensity of debris flow.Thus,the dynamic parameters of debris flow and the stability coefficient of retaining dam in different return periods were calculated in Chutou gully.And the debris flow hazard was evaluated based on dynamic parameters of debris flow and improved entropy method.And the control relationship between retaining dam and debris flow hazard was analyzed.The study findings were as follows:Reasonable evaluation results could be obtained by dynamic parameters and improved entropy method.The values of debris flow hazard were decreased about 12.27%~43.75%with different return periods(1%,2%,5%and 10%)under the influence of the retaining dam,due to the discharge of debris flow was decreased below the retaining dam.This work may provide some new clues for prevention and control of debris flow and optimum design of retaining dam.
作者
李永威
徐林荣
商拥辉
陈舒阳
Li Yongwei;Xu Linrogn;Shang Yonghui;Chen Shuyang(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Research Center of High-Speed Railway Construction Techology,Central South University,Changsha 410075,China;School of Civil Engineering,Central South University of Forestry and Technology,Changsha 410004,China)
出处
《地球科学》
EI
CAS
CSCD
北大核心
2024年第8期2839-2850,共12页
Earth Science
基金
国家面上项目(No.42172322)
国家自然科学基金项目(No.42007419)
国家重点研发计划(No.2018YFC1505403)
湖南省自然科学基金(No.2020JJ5981)
湖南省教育厅科学研究项目优秀青年基金(No.21B0226)
中南大学研究生自主探索创新项目(No.2022ZZTS0646)。
关键词
拦挡坝
动力特征参数
改进熵值法
泥石流危险性
工程地质
retaining dam
dynamic parameters
improved entropy method
debris flow hazard
engineering geology
