Dynamic Numerical Simulation Of Disasters Based On Single Layer Single Phase Flow And Multilayer Multiphase Flow

China is one of the most serious geological disasters in the world.Geological disasters which have many types,wide distribution and great influence restrict economic development and threaten the safety of people's lives and property.Numerical simulation is an important method to study the mechanism of disaster initiation,kinematics and evolution.However,compared with foreign countries domestic disaster numerical simulation software is few and lack of influence.Developing a simulation software with independent intellectual property rights and international advanced level to carry out the risk assessment and prediction based on dynamic process.It has great significance to improve the level of disaster reduction and international influence.The main work of this paper is as follows.Firstly the three-dimensional Navier-Stokes equation is reduced to a two-dimensional shallow water equation based on the theory of continuum mechanics.Then the governing equation is solved by the improved MacCormack-TVD finite difference method.Then integrate it into the Massflow software and develop a new computing module.It can be considered as a high efficient computational simulation software of mountain hazards with complex terrain,two order precision and adaptive domain.Secondly the module of new development is used to simulate the whole process of the collapse and sliding of the landslide under the excess pore water pressure in Shenzhen Guangming New District.The simulation results show that the numerical results are in good agreement with the field survey data and image data when the pore water pressure coefficient is 0.75.The excessive pore water pressure is an important factor to determine whether the landslide has the remote and high speed.It has positive significance to the post disaster reconstruction.Thirdly there are some defects and limitations in the conventional single phase flow or single layer flow.Based on this situation,this paper presents the numerical simulation of multilayer and multiphase flow.The landslide disaster caused by the underwater landslide and the dam break problem of two phase flow are successfully simulated.It solves the problem of single phase single phase flow model.It provides a new starting point for the numerical simulation of such disasters.