摘要
泥石流是介于崩塌、滑坡等块体运动和山洪水流之间的一种物理过程,既具有土体的结构性,又具有水体的流动性。从物质组成上看,泥石流是一种由水、岩土体和气体组成的多相介质,具有多种内部结构。其中的固相组分颗粒形状极其不规则,尺度跨越范围较大。浆体与固相颗粒以及颗粒间的相互作用非常复杂。因此,完全考虑各种因素建立全描述的泥石流动力学模型比较困难。从描述组成物质和运动的观点来看,目前泥石流的动力学模型可划分为连续介质、离散介质和混合介质模型。基于不同动力学模型的泥石流运动数值模拟,可广泛应用于流量过程反演、危险范围预测、风险评估、防治工程评估等方面;但泥石流本身启动和产汇流机理涉及多门学科,是需要进一步研究的重要课题。同时,泥石流形成过程和运动过程的数值模拟存在着时空尺度上的差异,如何实现两者的耦合求解仍需深入探讨。
Debris flow as one of the most active surface processes is an intermediate form of mass movement between mountain flood and landslide. It is a viscous and highly concentrated fluid-solid mixture, being shear-resistant like soil while flowing like water. As a typical multiphase flow, most of debris flows contain water, soil, rocks and gas, and have special inner structures. The solid grains of debris flows have very irregular shape, and their sizes range several orders of magnitude. The interactions between slurry and grain or grain and grain are complex. Therefore, it is very difficult to develop a dynamic model fully describing the debris-flow process. From the point of view of constituent prototype and motion description, the existing debris-flow dynamic models can be classified into continuum, discrete medium, and hybrid medium models. The numerical simulations based on these dynamic models are widely applied to back-analysis of debris flow discharge, predicting inundated region, risk assessment, and evaluating protection engineering etc. Comparing with the motion process of debris flow, the formation process of debris flow is an interdisciplinary research subject, and needs more attentions. Moreover, how to coupling the two processes with different spatial and temporal scales is still a challenging issue.
出处
《自然杂志》
北大核心
2014年第5期313-318,共6页
Chinese Journal of Nature
关键词
泥石流
动力学
数值模拟
本构关系
debris flow
dynamic model
numerical simulation
constitutive relation
