Macro and Meso Analysis on Suitability of Discrete Element Layered Model for Uniaxial Compression Test
In the particle distinct element method,using modeling method with different size scales inside and outside(layered model)can reduce computational complexity and effectively improve the accuracy of calculations,thereby modeling and calculating was conducted on problems in large-scale engineering such as tunnels and slopes.Although the layered modeling method is feasible in model generation and contact allocation,it is still unknown whether its mechanical properties under loading conditions is same as that of the conventional model and how about the matching degree is between calculation results and indoor tests.The effectiveness of the rock layered model for uniaxial compression test was analyzed from the macro and meso perspective,and the influences of the outer and inner layer average particle size ratios and the size of the inner layer model on the compressive strength of the layered model were explored.The research results show that the layered structure of the layered model won't have an abnormal effect on its macro mechanical properties under uniaxial compression.Force can be transmitted normally at the interface between layers,but the layered structure will make the model absorb,store,and consume more energy.The uniaxial compressive strength of the layered model increases with the increase of outer and inner layer average particle size ratio.As the volume of the inner layer increases,the uniaxial compressive strength of the layered model shows a trend of first increasing and then decreasing.When the layered model is used to match the uniaxial compressive strength of the rock specimen,the average particle sizes of the inner and outer layer and the volume of the inner layer model need to be determined first to improve the efficiency of parameter matching.The average particle sizes of the inner and outer layers were ultimately selected to be 2 mm and 3 mm,respectively,with an outer and inner volume ratio of 7.00.The rock layered model can show the same uniaxial compression mechanical properties and macroscopic failure characteristics as the laboratory test,and the layered structure has no abnormal effect on the development of cracks from meso to macro perspective.
Layered modelDiscrete element methodUniaxial compression testMechanical propertyFailure characteristic
万方数据
维普
