拦挡作用对黄土坡面泥流动力过程影响机制  

The Influence of the Blocking Effects on Dynamic Process of Loess Slope Debris

作　　者：华山 贾晓丹 张霞[3] HUA Shan;JIA Xiaodan;ZHANG Xia(School of Earth Sciences and Resources,Chang’an University,Xi’an 710054,Shaanxi,China;Xi’an Center of China Geological Sur-vey/Northwest China Center for Geoscience Innovation,Xi’an 710119,Shaanxi,China;State Key Laboratory of Eco-hydraulics in North-west Arid Region,Xi’an University of Technology,Xi’an 710048,Shaanxi,China)

机构地区：[1]长安大学地球科学与资源学院,陕西西安710054 [2]中国地质调查局西安地质调查中心/西北地质科技创新中心,陕西西安710119 [3]西安理工大学,西北旱区生态水利国家重点实验室,陕西西安710048

出　　处：《西北地质》2024年第3期285-292,共8页Northwestern Geology

基　　金：国家自然科学基金项目“黄土丘陵植被与淤地坝调控重力侵蚀的协同作用机制”(42177346);“黄土高原粗沙区水沙产输机理与模拟模型”(U2243240);“基于侵蚀能量的坡面植被与沟道淤地坝耦合效能研究”(52009103)联合资助。

摘　　要：泥石流运动过程中拦挡坝的拦挡作用是泥流防治研究中的一项重要议题。本研究引入侵蚀速率概念,建立了含有拦挡坝的泥流连续介质模型,阐明了拦挡坝拦挡作用对泥流运动行为和动力过程的影响。结果表明,泥流撞击拦挡坝发生漫坝时,拦挡坝遭受了逐渐加速泥流巨大的影响。拦挡坝发挥出拦截和拦挡双重功效:一方面,使得泥流灾害体横向扩展增强,纵向延伸减弱,滑移距离减少,降低了泥流的致灾范围;另一方面,降低了泥流侵蚀夹带作用,减少了泥流灾害体质量,使得灾害体面积和体积分别下降2.48%和3.63%。同时,使泥流偏离流动方向,泥流运动的平均速度下降10.62%,缓解了泥流的冲击力,削减了灾害体16.17%的致灾能量,进一步降低了泥流的致灾强度和致灾规模。引入基底地形和侵蚀速率的数值模型为泥石流动力机制提供理论支持,也为泥流防治提供技术指导。The blocking effect during debris flow movement is an important topic in in the study of debris flow prevention.In this study,the concept of erosion rate is introduced,established a continuous model of debris flow including blocking dam,and clarified the effect of the dam on debris flow movement behavior and dynamic pro-cess.The results show that the planned mitigation works would suffer tremendous impact caused by the acceler-ating debris.The blocking dams perform the dual function of intercepting and blocking,the blocking dam plays a dual role of interception and blocking,which makes the lateral extension of the debris flow disaster body en-hanced,the vertical extension weakened,and the slip distance reduced,reducing the debris flow disaster scope.On the other hand,it reduces the erosion entrainment effect of debris flow,reduces the mass of disaster body,and decreases the area and volume of disaster body by 2.48%and 3.63%respectively;meanwhile,it deviates the flow direction,decreases the average velocity of mudflow movement by 10.62%,alleviates the impact force of debris flow,reduces the disaster energy of disaster body by 16.17%,and further decreases the disaster intensity and scale.The numerical model introduced by basement topography and erosion rates provides theoretical sup-port for debris flow dynamics mechanisms and technical guidance for debris flow prevention.

关 键 词：泥流 拦挡坝 动力机制 致灾能量 

分 类 号：P694[天文地球—地质学]