Research On Simulation Reconstruction And Mechanical Properties Of Widely Sourced Cemented Granular Material Discrete Numerical Model

As the main damming material of Cemented Granular Material Dam(CGMD),the research on mechanical properties of Cemented Granular Material(CGM)is indispensable with the extension and application of CGMD.At present,the mechanical properties of CGM are mainly carried out by physical experiments,which cost a lot and have a long test period.With the rapid development of computer technology,economic and convenient numerical simulation with short test period has become an effective tool to study the mechanical properties of CGM.However,due to the heterogeneous heterogeneity of CGM,the construction of numerical model of CGM has become the main problem limiting the application of numerical simulation methods.Started from the simulation reconstruction of discrete numerical model for CGM,this paper studies the mechanical properties and applications of cemented granular material through the combination of theoretical analysis and numerical experiments.The main research contents are as follows:(1)A three-dimensional digital aggregates simulation reconstruction algorithm for CGM with real aggregates characteristics was established.For the problem that it is difficult to generate digital aggregates with real aggregate characteristics in numerical simulation method,the three-dimensional aggregates reconstruction method based on two-dimensional contour features is used to simulate and reconstruct the threedimensional digital aggregates.The reconstruction results are compared with the real aggregate information obtained by 3D scanner,which proves the effectiveness and efficiency of the algorithm.(2)A simulation reconstruction algorithm for the numerical model of CGM containing four phases(aggregate,interface,cementation and pore)is proposed.Aiming at the problem that it is difficult to characterize the heterogeneity of each phase in CGM,through importing aggregate phase by 3D-digital aggregate packing algorithm,importing interface phase by burning algorithm,and using simulated annealing algorithm to optimize the spatial distribution of cementing phase and pore phase based on the minimum energy principle and the law of two-phase flow distribution,realized the simulation reconstruction of the numerical model for four-phase widely sourced cemented granular material eventually.(3)A mathematical model for predicting the uniaxial compressive strength of CGM is established.For the requirement of rapidity and simplicity of strength determination of CGM in engineering,the influence factors of strength of CGM are systematically studied by using the four-dimensional discrete spring model based on GPU heterogeneous parallel,and a simple strength prediction formula which is easy to be applied in engineering is proposed.In addition,the influence of dam materials on the safety of CGMD is analyzed,and the influence of the variability of dam materials of different strength grades on the safety coefficient of CGMD in stable impoundment period is analyzed.