基于PIV技术的冰-岩碎屑流运动特性斜槽实验研究  

Experimental Study on Mobility of Rock-Ice Avalanches by Flume Test Using PIV Technology

作　　者：覃耀 杨情情[1] 罗鑫[1] 佟璐冶 余晨[1] QIN Yao;YANG Qingqing;LUO Xin;TONG Luye;YU Chen(Faculty of Geosciences and Engineering,Southwest Jiaotong University,Chengdu 611756,China)

机构地区：[1]西南交通大学地球科学与工程学院,成都611756

出　　处：《山地学报》2025年第1期144-156,共13页Mountain Research

基　　金：国家自然科学基金(42277127);四川省自然科学基金(2022NSFSC1164)。

摘　　要：冰-岩碎屑流作为高寒山区特有的多相复合型地质灾害,其运动过程涉及复杂的流固耦合效应。现有研究对微量相变水介导的固液耦合作用及其对颗粒流剪切力学行为与堆积形态的影响机制仍显不足。本研究采用斜槽实验,结合粒子图像测速技术(PIV),定量解析不同含冰量(0%、20%、40%和60%)条件下冰-岩混合材料的动力学响应规律及堆积特征。实验结果表明:(1)含冰量增加通过降低颗粒间摩擦系数显著提升物质运移能力。(2)薄层水膜润滑效应与毛细吸附阻力之间相互作用主导颗粒流运动状态。随融水量增加,颗粒表面水膜逐渐增厚,初期产生润滑作用,降低摩擦阻力,从而增强冰-岩混合材料的运动性和堆积体的侧展程度。进一步的水膜增厚导致毛细吸附作用增强摩阻,抑制运动性和堆积体的侧展。(3)剪切变形场呈现显著层状分异特征。冰屑糙率较小,多集中在颗粒流上层,受外力影响较小,保持了层间稳定性和速度一致性。底部岩屑剪切层的剪切速率高于表层冰屑剪切层,其剪切速率随层内冰屑含量增加而减小。(4)惯性数分析表明,20%和40%含冰量颗粒流的惯性数小于0.5,均呈现密集流特征,且40%含冰量颗粒流的惯性数更低。冰相组分通过抑制颗粒碰撞显著增强颗粒流的密集态流动特征。本研究有助于深化冰-岩碎屑流的运动机理和流态特征,为高寒山区冰-岩碎屑流的防灾减灾工作提供科学依据。As a unique multiphase compoiste geo-hazard in alpine-cold areas,a typical gralular flow,rock-ice avalanches bear complex fluid-solid coupling effects during movements.There were quite unknow about rock-ice avalanches regarding its solid-liquid coupling mechanism mediated by trace phase change water and the consequence to the shear behavior and accumulation morphology.In this study,flume experiments combined with Particle image velocimetry(PIV)were used to quantitatively analyze the dynamic response laws and deposition characteristics of gravel-ice mixtures under different ice content conditions(0%,20%,40%and 60%).(1)The increase in ice content in rock-ice avalanches significantly enhanced the material transport ability by reducing inter-particle friction coefficient.(2)The interaction between the lubrication effect of thin-layer water film and capillary adsorption resistance dominated the movement state of rock-ice avalanches.As meltwater amount grew,water film on particle surfaces thickened,which initially decreased friction and thus enhanced the mobility and lateral spreading of the accumulation,but with further water increased,capillary adsorption effects arose,leading to increased friction that restricted both mobility and lateral spreading.(3)In the shear deformation field,it exhibited significant layered differentiation characteristics.Ice particles had a smaller roughness and were mostly concentrated in the upper layer of rock-ice avalanches,experiencing less influence from external forces and maintaining interlayer stability and velocity consistency.The shear rate in the bottom debris shear layer significantly exceeded that of the surface shear layer,with shear rate progressively reducing as ice content increased within the stratified structure.(4)It found by inertial number analysis that the inertial numbers of 20%and 40%ice-content graluar flows were less than 0.5,both of which showed dense flow characteristics,with even lower inertial number for the flow of 40%ice-content.The ice-phase component signi

关 键 词：冰-岩碎屑流 斜槽实验 含冰量 融水量 剪切速率 流态特征 

分 类 号：P642.2[天文地球—工程地质学]