Dam-break Model Test And Numerical Simulation Study On Dry Ash Storage Yard

Ash storage yard is a place used to store fly ash and slag produced by coal-fired power generation in thermal power plants.It is an artificial hazard source with high potential energy.Once the ash storage yard breaks the dam,the ash stored in the reservoir area will be poured down,causing serious disasters to downstream residents and facilities along the line.Mud flow downflow after the dam break of the ash storage yard is a complex problem with multiple factors,and the relevant research data is very lacking.At present,the calculation and research methods of the dam break of the reservoir are used for reference.Therefore,strengthen the research on the dam failure of the ash storage yard.Site selection and disaster prevention and mitigation work are of great significance.Based on a certain ash storage project in Yidu City as the research background,this paper uses a combination of indoor scale model test and numerical simulation to design two dam break methods,and detailed the evolution process of dam-break mud flow in the ash storage yard.According to the records and analysis of the ash yard,the fluid evolution process and the damage degree of the facilities along the downstream line under the full failure mode and the failure mode of the ash storage dam are obtained,which provides a theoretical basis for the feasibility study of the ash storage site selection.The main research contents are:(1)The on-site fly ash is tested and analyzed according to the indoor geotechnical test method,and the physical and mechanical property parameters of fly ash are obtained as the basic data for studying the dam break of the ash storage yard.(2)Based on the site survey data of a certain ash storage site,a three-dimensional indoor scale model was established,and a dam-break scale model test of the ash storage yard was carried out based on the similarity theory.By monitoring and recording the downstream mud flow evolution process in the reservoir area,the flow depth,velocity,maximum inundation range and maximum discharge flow at the downstream key nodes and cross-sections were analyzed in detail,and the evolution law of mud flow under dam break of the ash storage yard was obtained.(3)Introduced the basic principles and use methods of the Massfflow numerical simulation software for the dynamic process of surface disasters,and established the DEM threedimensional terrain of the ash storage yard with the Arc GIS software and CASS software.The chute model was made,and the sensitivity of the parameters in the Voellmy rheological model was analyzed in conjunction with Massflow software.Import the terrain and provenance DEM data into Massflow software for dam-break mud flow simulation calculation,and analyze the sedimentation height of the discharged fluid and the mud flow velocity changes at key crosssections.The physical model test and the numerical simulation results are compared and analyzed to study the dynamic evolution process of the dam-break mud flow of the ash storage yard,the post-break siltation range,and the downstream disaster degree.