漫顶溃坝过程的水土耦合数值模型研究
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摘要
针对溃坝过程中水流与溃口变化快、相互作用强烈耦合的特点,采用无网格基于Lagrange描述的光滑粒子动力学(Smoothed Particle Hydrodynamics-SPH)方法,引入土体的弹塑性本构关系,构建了土体变形破坏的三维力学模型、水土耦合界面作用模型和一种新的水土耦合冲刷模式,建立了能够较为完整地描述土石坝漫顶溃决过程的水土耦合数值模型。算例模拟表明,该模型能够合理地描述水流对土体的冲刷发展过程。
The shape of dam breach section evolves rapidly because of the rapid erosion, bank collapse and interaction between them in the overtopping induced earth dam failure process. A new developed soil-water coupling model is introduced to simulate the dam breach process. The method is developed in the framework of the Lagrangian meshfree Smoothed Particle Hydrodynamics(SPH) method, includes three sub-models as the Naiver-Stokes equation based water flow model, the elasto-plastic model for the soil, and the interaction model for soil and water interface and erosion model. With the ability of the dam break flow simulation, the erosion process and the embankment collapse, the model could simulate the whole process of breach formation and evolvement due to overtopping. A simple three dimensional test case of the overtopping failure of an earth dam with a prescribed breach is studied by this model. The simulation results indicate that the model could soundly represent key features of the breach evolvement and the entire dam failure process.
The shape of dam breach section evolves rapidly because of the rapid erosion, bank collapse and interaction between them in the overtopping induced earth dam failure process. A new developed soil-water coupling model is introduced to simulate the dam breach process. The method is developed in the framework of the Lagrangian meshfree Smoothed Particle Hydrodynamics(SPH) method, includes three sub-models as the Naiver-Stokes equation based water flow model, the elasto-plastic model for the soil, and the interaction model for soil and water interface and erosion model. With the ability of the dam break flow simulation, the erosion process and the embankment collapse, the model could simulate the whole process of breach formation and evolvement due to overtopping. A simple three dimensional test case of the overtopping failure of an earth dam with a prescribed breach is studied by this model. The simulation results indicate that the model could soundly represent key features of the breach evolvement and the entire dam failure process.
引文
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[2] Zhu Y H,Visser P J,Vrijling J K.Soil headcut erosion:process and mathematical modeling [M].in:Kusuda,Yamanishi,Spearman and Gailani (Eds),Sediment and Ecohydraulics,Amsterdam,the Netherlands,2008:125-136.
[3] Xia J,Lin B,Falconer R A.Modelling dam-break flows over mobile beds using a 2D coupled approach [J].Advances in Water Resources,2010,33(2):171-183.
[4] Cao Z,Yue Z,Pender G.Landslide dam failure and flood hydraulics.Part II:Coupled Mathematical Modelling [J].Natural Hazards,2011,59(2):1021-1045.
[5] Liu G R,Liu M B.Smoothed particle hydrodynamics:a meshfree particle method [M].World Scientific Publishing Company,2003.
[6] Monaghan J J.Simulating free surface flows with SPH [J].Journal of Computational Physics,1994,110(2):399-406.
[7] Shi C Q,An Y,Liu Q Q,Cao Z X.Numerical simulation of landslide generated waves using soil-water coupling SPH model [J].Advances in Water Resources,2016,92:130-141.
[8] An Y,Wu Q,Shi C Q,Liu Q Q.3D SPH Simulations for large deformation of slope failure [J].Geotechnique,2016,66(8):670-680.