ESR2 Xiaogang Guo

Research project description

Hypoplastic constitutive model for unsaturated soil and debris materials

Name of fellow:    Xiaogang Guo (ESR2)

Department:          Department of Civil Engineering and Natural Hazards, University of Natural Resources & Life Sciences, Vienna (Boku)

Supervisor:            Univ. Prof. Dr. -Ing. Wei WU

Debris flows are serious geo-hazards common to countries with mountainous terrains. Globally, debris flows cause billions of dollars in damage and thousands of deaths and injuries each year.

This project aims to develop advanced constitutive model of debris flow for better understanding of the triggering mechanisms, for reliable prediction of runout dynamics and for rational design of stabilization and protection structures. Debris materials involve solid particles and interstitial fluid. A hypoplastic constitutive model will be developed covering the solid-like and fluid-like behaviour and considering the major factors like plasticity, density, dilatancy and viscosity. The hypoplastic model proposed by Prof. Wei Wu in 1992 will be extended by integrating with material parameters of debris flow based on hypoplasticity and rheology. 

Some concepts developed in Task 1.1 (ESR1: Constitutive models of saturated and unsaturated soils) will be incorporated. The results of Task1.3 (ESR3: Micro-macro relationships based on DEM) will be used to help developing and calibration of the constitutive models. This model will be made available to WP2 and WP3.

                       

Figure 1. Yield surface and flow rule of hypoplastic model