Study On The Application Of Nonlinear Scaled Boundary Finite Element On Earth Rockfill Dam Analysis

The earth rockfill dam has become the preferred dam type in dam construction,because of its advantages such as making full use of local materials,less engineering quantity and short construction period.The finite element method has become the most important means of dam safety evaluation,because of its advantages of simple,robust,and universal nature.As the limitation of element shape in traditional FEM and the geometrical complexity of structures(such as layered construction and complicated material partition et al),a versatile and high-quality meshing discrete algorithm is comparatively difficult to implement,resulting in the majority time is consumed in element generation,which hinder the rapid process of automated analysis.Nonlinear scaled boundary finite element method(NSBFEM)combines the advantages of boundary element method(BEM)and the traditional finite element method(FEM).But the application of this method is seldom used in actual engineering.In this paper,a new-developed method of NSBFEM combined mesh automatic discrete algorithms(quadtree or octree),which utilized to analyze the static,dynamic and permanent deformation characteristics of earth rockfill dam engineering field.And it is verified the correctness of the implementation method,and the rapid modeling and numerical analysis method is developed to conduct the elastoplastic simulation of geotechnical structures.The main contents of this paper are as follows:(1)A new-developed method combining NPSBFEM and the quadtree discretization is utilized to analyze the static,dynamic and permanent deformation characteristics of the typical core rockfill dam.And it is verified by comparing with the FEM.The results show that NPSBFEM is reasonable and high in coincidence,which can be applied to the whole-process numerical analysis of static,dynamic and permanent deformation of a dam.(2)A new-developed method combining NPSBFEM and the quadtree discretization is utilized to concrete-faced rockfill dam.It is verified that the NPSBFEM has extraordinary mesh freedom,which can quickly perform cross-scale refinement analysis,improve the analysis efficiency.And NPSBFEM make it possible for the rapid cross-scale refinement modeling and analysis.Meanwhile,it can provide technical support for structural local damage evolution and progressive failure.And provide technical support for structural damage evolution and gradual damage.Additionally,the flexible mesh editing simplifies the cumbersome data interaction processes in the traditional engineering design-simulation analysis,which avoids the massive duplicated work and improves automation process.And complex boundary processing capabilities avoids the cumbersome to describe the shape of the boundary.(3)The improved nonlinear polyhedral scaled boundary finite element method(NPSBFEM)and FEM were used to analyze the static,dynamic and permanent deformation of the conventional three-dimensional homogeneous core rockfill dam.The numerical results of the two methods were compared and analyzed.Verify the correctness of the NPSBFEM program.(4)Using the NPSBFEM combined rapid mesh discretization technique,the numerical analysis of the asphalt core wall dam project shows that the implementation method can be as convenient as FEM to carry out the numerical analysis of actual engineering.The seamless coupling of the quadtree and the octree grid can avoid the time-consuming and cumbersome grid transformation and greatly improve the degree in automation.It is proved that this method can be applied to the numerical simulation of earth rockfill dam,and provides a new method for the numerical analysis and safety evaluation in earth rockfill dam.