Research On Modeling Lateral Enlargement In Dam Breach And Virtual Reality Technology Of Earth Dam

Earth dams are widely used due to their characteristics of local materials,simple structure and simple construction.In China,the number of earth dams accounts for 95%of the total number of dams.While earth dams play an important role,there are also potential safety hazards.Once the earth dam breaks down,it will cause a serious blow to the downstream and threaten people’s production and living safety.The dam breach mainly includes three aspects:the discharge process line,enlargement of dam breach and the flood routing.The enlargement of dam breach affects the calculation of the discharge process line and thus the progress of the flood routing.In the most of the existing breach models,the lateral enlargement is usually modeled using a wedge failure analysis with a straight line surface subjected to gravity and seepage forces.The result is quite different from the actual dam breach phenomenon.In addition,when the earth dam is facing a collapse,it will be important to show government decision-makers the influences of dam breach.However,there are few studies on the three-dimensional dam breach virtual reality.This paper mainly carried out the research on modeling lateral enlargement in dam breach and virtual reality technology of earth dam,and got the fllowing conclusions:(1)Use slope stability analysis based on circular slip mode to modeling lateral enlargement in dam breach.To solve the modeling,develop a slope stability program DBS-IWHR based on Excel VBA.This program can calculate the safety factor of a specified circular sliding surface.It also provides enumeration method and simplex method to complete the critical slip surface search.This program can provide technical support for engineering staff to quickly calculate the modeling lateral enlargement in dam breach.;(2)For small basin earth dams with no topographic data,a fixed-wing UAV is used to aerialize small watersheds to obtain high-precision DEM elevation data and orthographic projection images.On the basis of high-precision topographic data,the DB-IWHR model was used to calculate the flood discharge process line of the dam breach,and this result was input as a boundary condition to the MIKE21 model to calculate the downstream flood evolution process.Finally,the calculation results of MIKE21 are imported into the ArcGIS platform.The ArcGIS platform can be used to visually observe the changes of flood inundation area,water depth,and other data over time.(3)Using 3ds Max,Realflow,Rayfire and other virtual reality software to integrate accurate 3D ground models,city streets models and buildings models.In the virtual scene,reproduce the earth dam field conditions,and demonstrate the development of the breach,the collapse of the slope and the flood evolution process(4)Develop a three-dimensional scene roaming management system based on Java and Unity3d.This system provides the management function of houses in the dam area and the roaming function in the virtual scene of the dam area.