高速远程滑坡颗粒流研究进展

颗粒流是高速远程滑坡物质演化过程的一个重要阶段，也是从细观角度揭示其超常运动特性的重要手段.颗粒流所采用的主要研究方法以及取得的重要理论成果，可以为高速远程滑坡动力学机理的研究提供重要的技术手段和理论支持.本文聚焦颗粒流研究进展，从颗粒流基本概念、流态特征及流变本构模型、颗粒流粒径分选机制等方面进行了系统梳理；进而，从理论、实验及数值计算模型3个方面对高速远程滑坡研究中颗粒流理论及方法的应用进行了系统性述评；在此基础上，提出了从颗粒流角度研究高速远程滑坡动力学机理涉及的关键科学问题:高速远程滑坡高流动性的起源涉及哪些物理过程？如何量化和模拟其多分散性和破碎过程？如何量化描述颗粒尺寸分布的时空演变及其与流动的耦合？如何从其沉积特征中探究流动的传播机制？针对这些问题，从基于沉积学特征的颗粒流物理力学过程、考虑尺度效应的颗粒流动力学特性研究、基于颗粒流力学过程的滑坡运动机理及其本构模型、新技术新方法的应用4个方面提出下一步应重点开展的研究工作. 

State of the Art on Rock Avalanche Dynamics from Granular Flow Mechanics

Granular flow is a main stage in the propagation of rock avalanches, which is of significant importance for revealing the hypermobility of rock avalanches. The main methods and theoretical achievements of granular flow can provide important technical means and theoretical basis for the study of rock avalanche dynamics. Focusing on the research of granular flows, its current research progress is reviewed firstly from the perspectives of its concept, flow regimes and corresponding constitutive models, and size-segregation mechanisms. Then, the granular flow theories and methods involved in rock avalanche research are systematically reviewed from the aspects of theoretical analysis, experiments and numerical modeling. On these bases, the key issues involved in the research of rock avalanche dynamics are proposed from the viewpoint of granular flow, i.e., what physical processes is related to the hypermobility of rock avalanche? How to quantify and model its polydispersity and fragmentation? How to quantitatively describe the temporal and spatial evolution of its grain size distribution and related coupling processes? How to retrieve its propagated mechanisms from the deposit? Facing these problems, future works that should be focused are proposed, including research on the physical processes of granular flow from sedimentology, on granular flow dynamics with scale effect considered, on the dynamic mechanisms and their constitutive models of rock avalanche based on the physical processes, and on the application of new technologies and methods.