密度及粒径差异对冰岩碎屑流分选模式及冲击力的影响  

Grain Density and Gradation Jointly Regulate the Grain Segregation Patterns and Impact Force Effects in Rock-Ice Debris Flow

作　　者：杨钧凯 姜元俊[3] 阿比尔的 朱元甲 刘宇桐 YANG Junkai;JIANG Yuanjun;ABI Erdi;ZHU Yuanjia;LIU Yutong(National Engineering Research Center for Inland Waterway Regulayion,Chongqing Municipal Education Commission,Chongqing Jiaotong University,Chongqing 400074,China;Key Laboratory of Geological Disaster Reduction for Highway and Waterway Transportation in Mountainous Areas,Chongqing Municipal Education Commission,Chongqing Jiaotong University,Chongqing 400074,China;Key Laboratory of Mountain Hazards and Engineering Resilience,Institute of Mountain Hazards and Environment,Chinese Academy of Sciences&Ministry of Water Resources,Chengdu 610213,China)

机构地区：[1]重庆交通大学国家内河航道整治工程技术研究中心,重庆400074 [2]重庆交通大学山区公路水运交通地质减灾重庆市教委重点实验室,重庆400074 [3]中国科学院、水利部成都山地灾害与环境研究所山地自然灾害与工程安全重点实验室,成都610213

出　　处：《山地学报》2024年第6期816-826,共11页Mountain Research

基　　金：国家自然科学基金(42172320)。

摘　　要：冰岩碎屑流在运动过程中,因岩石颗粒和冰颗粒之间存在显著的密度差异,产生颗粒分选现象,影响其流动特性和冲击效应,最终改变冰岩碎屑流的致灾性。前期研究多采取室内实验研究的方法,检验单一颗粒性质对颗粒分选的影响,并没有考虑颗粒粒径差异和密度差异对冰岩碎屑流颗粒分选的综合影响。本文采用室内物理模型实验与数值模拟,探究冰岩碎屑流在岩石和冰的粒径及密度差异下的运动过程。由于冰岩碎屑流物质组成的复杂性,本研究假设岩石和冰均为单一、均匀粒径,简化岩石和冰的粒径级配,仅考虑岩石与冰之间的粒径比,分析岩-冰粒径比对颗粒分选模式及冲击力的影响规律。结果表明:(1)岩石和冰的粒径差异能够显著改变颗粒分选模式,形成两种不同的分选模式:大颗粒冰-小颗粒岩石的上层冰-下层岩、前方冰-后方岩模式,以及小颗粒冰-大颗粒岩石的上层岩-下层冰、前方岩-后方冰模式。(2)粒径差异与颗粒的分选程度呈显著正相关,即粒径差异越大,分选程度越高。(3)颗粒分选模式显著影响冰岩碎屑流的冲击力。具体而言,上层冰-下层岩、前方冰-后方岩模式对挡板的冲击力小于上层岩-下层冰、前方岩-后方冰模式,且上层冰-下层岩、前方冰-后方岩的分选模式导致能量耗散更大。本研究可以为揭示冰岩碎屑流的颗粒分选机制及冰岩碎屑流灾害防治提供理论依据。In the movement of an ice-rock debris flow,it occurs a natural phenomenon of sorting rock particles from ice particles possibly because of sharp distinction in density between ice-grain and rock-grain,which affects its flow behavior and impact effect,and finally alters the catastrophic consequence of an ice-rock debris flow.Most of previous studies took an approach of indoor experiments to examine the effect of single particle properties on particle sorting,but did not consider the combined action of differences in both particle size and density on grain sorting in moving ice-rock debris flows.In this paper,it used indoor physical modeling experiments and numerical simulations to investigate the motion process of ice-rock debris flow under the density difference between rock and ice particles.Due to the complexity of the material composition of an ice-rock debris flow,this study assumed that both rock and ice were of a single,homogeneous particle size,and considered only the particle size ratio between rock and ice included in the simplified gradation model,and then analyzed the influence law of rock-ice particle size ratio on particle sorting mode and impact force.(1)The difference in particle size between rock and ice significantly changed particle sorting pattern,resulting in two distinct sorting modes for a ice-rock debris flow body.One mode was of large particle ice in the upper layer with small rock particle in the lower layer in the ice-rock flow body(upper ice-lower rock model),or ice in the front with rock in the rear along an ice-rock flowing body(front ice-rear rock model),whereras another mode was small particle ice in the lower layer with large rock particle in the upper layer(upper rock-lower ice model),or rock in the front with ice in the rear(front rock-rear ice model).(2)There was a significant positive correlation between the difference in particle size and the degree of sorting of particles,i.e.,the larger the difference in particle size,the higher the degree of sorting.(3)Particle sorting patt

关 键 词：冰岩碎屑流 颗粒分选 粒径差异 密度差异 冲击力 

分 类 号：TU432[建筑科学—岩土工程]