報告題目：The Motion Characteristics of Granular Assembly
主講人：Dave Hung Kwan Chan PhD, P.Eng.
Dr. Dave Chan is currently a Professor and the Associate Chair of Graduate Studies of the Department of Civil and Environmental Engineering at the University of Alberta in Canada. Dr. Chan has been involved in the analysis in a number of large geotechnical structures. His expertise and research interest lies in computer analysis of soil deformation, constitutive modelling, liquefaction, slope stability, debris flow and soil mobility analysis. He has published many papers on computer analysis in geotechnical engineering. He has provided geotechnical consulting advice on a variety of projects from site investigation to construction, to state of the art finite element simulations on the deformation and stability of building foundation, tunnels and earth structures.
Abstract: Debris flow consists of unsorted assembly of granular material of different particle sizes. Debris flow is a type of granular flow in which interparticle friction dominate the flow characteristics. There are several approaches in analyzing debris flow which can be broadly classified into continuum and discontiuum approaches. The behavior of granular material in motion is different than that under static condition. The effect of particle inertia plays an increasing important role when particle velocity is increased. To understand the behavior of granular flow, numerical experiments have been carried out to explore the frictional and volumetric behaviour of granular material. With increase in particle velocity, particle inertia results in an increase in resistance against motion and, at the same time, a decrease in interparticle contacts which results in less frictional contribution to the overall resistance. Volumetric deformation is important in granular deformation under statisc condition and it is equally important in granular flow. Physical experiment has been carried out on granular material in which vibration is applied after the material has been sheared statically. It is found that vibration results in volumetric compaction below the critical state volume which results in subsequent increase in shearing resistance of the material. In this seminar, the behavior of granular material under motion will be examined using numerical and physical experiments.