泥石流透过型拦砂坝群结构优化设计  

Optimization Design of Permeable Debris Flow Check Dam Cascade

作　　者：刘兆旭 任锦程 赵艳青 苏鹏程 汪洋[2] 龚旭[2,4] LIU Zhaoxu;REN Jincheng;ZHAO Yanqing;SU Pengcheng;WANG Yang;GONG Xu(College of Engineering,Tibet University,Lhasa 850032,China;Institute of Mountain Hazards and Environment,Chinese Academy of Sciences&Ministry of Water Resources,Chengdu 610213,China;Beijing Engineering Corporation Limited,Power China,Beijing 100024,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]西藏大学工学院,拉萨850032 [2]中国科学院、水利部成都山地灾害与环境研究所,成都610213 [3]中国电建集团北京勘测设计研究院有限公司,北京100024 [4]中国科学院大学,北京100049

出　　处：《山地学报》2024年第6期791-804,共14页Mountain Research

基　　金：国家重点研发计划(2022YFC3002905);国家自然科学基金(42271092);中国科学院西部青年学者项目(E2R2180180)。

摘　　要：泥石流常采用拦砂坝坝群布局工程措施。如何达到泥石流拦砂坝群,尤其是透过型拦砂坝群在多级拦截下的最优协同作用,是目前研究的难点。本文选择司地沟为研究区,在无人机数据和野外考察的基础上,以透过型拦砂坝群的重要设计参数开口比作为主要研究参数,采用基于改进MacCormack-TVD有限差分法的Massflow软件对开口比L为1、2、3的梳齿坝群进行数值模拟,得到泥石流在不同L条件下的泥深、流速及堆积面积。研究结果表明:(1)降雨频率为1%时,泥石流运动至沟口的最大泥深为11.4 m,最大流速为16.50 m·s^(-1),在沟口形成堆积面积为35.86×10^(4)m^(2)的堆积扇。(2)拦砂坝群可有效拦截泥石流物质量,最大泥深出现在坝前,泥石流运动时长随开口比增加而减小,开口比为1时泥石流运动至3号坝址处的时间有效延长了100 s。(3)坝前后流速随开口比L增加而增加,坝前拦截物质量随开口宽度增大而减小;随L增大,1号坝功能由拦截向排导转变,2号坝拦截效能呈现先增加后减小的趋势,主要拦截物质由1、2号坝向2、3号坝转变,L=3为研究区拦砂坝群最佳开口比。本文针对泥石流透过型拦砂坝群结构优化设计的关键参数,通过理论分析与数值模拟,系统探讨透过型拦砂坝群设计中关键参数的影响机理及优化设计策略,以期为实际工程提供技术参考。Engineering measures for debris flow control often employ the layout of a cascade of check dams.An engineered challenge for building a check dam cascade lies in achieving a designed synergistic effect of each dam in the grouping dams,especially to the utmost exploiting a cluster of permeable check dams designed with a function of cascading debris interception.In this study,it selected the Sidi Gully as a research case.It used field surveys,satellite remote sensing and high-precision unmanned aerial vehicle(UAV)remote sensing to identify the topographic characteristics and geo-source distribution of the debris flow gully;it used Massflow software based on improved MacCormack-TVD finite difference method,to establish a spatial layout model of the comb-tooth dam cascade,which set different opening sizes for the dams in concert to specified opening ratios for design optimization;numerical simulations were conducted for the dams and acquired a series of design outcomes,such as mud depth,velocity,and accumulation area with opening ratios(L)of 1,2 and 3.(1)At a rainfall frequency of 1%,the maximum mud depth at the Gully mouth reached 11.4 m,with a peak velocity of 16.50 m·s^(-1),forming a depositional fan with an area of 35.86×10^(4)m^(2).(2)The check dam cascade effectively intercepted debris in debris flow body,with the maximum mud depth occurring upstream of the dams.As the opening ratio increased,the duration of debris flow decreased.When the opening ratio set at 1,the debris flow body took an additional 100 seconds to reach the third dam location.(3)The flow velocity at locations of before and after the dams increased with a larger opening ratio,while the mass of intercepted geo-material upsteam of the dam decreased as opening widths enlarged.As L increased,the function of No.1 dam shifted from interception to diversion,while the interception efficiency at No.2 dam initially increased and then decreased.The main interception roles transitioned from No.1 dam/No.2 dam to No.2/No.3 dam,with L=3 identified as the opt

关 键 词：泥石流 设计优化 Massflow 透过型拦砂坝群 开口比 

分 类 号：X43[环境科学与工程—灾害防治] P642.23[天文地球—工程地质学]