| Rock-fill dams are widely used in engineering practice due to their many advantages,such as high bearing capacity,good water permeability,high seismic performance,good adaptability,saving engineering costs,and convenient access to materials.As the height of rock-fill dams continues to increase,rock-fill materials are the main building materials of rock-fill dams,and their mechanical properties and deformation have a significant impact on the safety of the dam.Rock-fill particles will be broken under high stress.Particle crushing will change the gradation and mechanical properties of the rock-fill material,causing the settlement and deformation of the rock-fill dam body,which will seriously harm the antiseepage performance of the dam body.The general research on the mechanical properties of rock-fills is carried out using indoor physical experiments.However,due to the limitations of indoor tests,it is impossible to observe the meso-mechanical properties during the experiment.Therefore,the mechanical properties of rock-fills under the condition of particle crushing are considered.Research is hard to get in-depth study.With the gradual development of computer technology in the engineering field,numerical simulation methods have become an effective method for studying the mechanical properties of rock-fill particles.In view of this,this article has carried out the biaxial simulation test of rock-fill samples with different configurations around the particle crushing characteristics of rock-fill particles,and explored the effect of different particle configurations on the macro and micromechanical properties of rockfill materials under the condition of particle crushing.influences.The main research contents are as follows:(1)Use PFC2 D software to establish a biaxial loading test model,generate clump rigid clusters in the model,and then fit the shape of clump particle clusters with ball to replace clumps to generate a crushable rock-fill particle model.Through simulating indoor physical experiment,adjusting various parameters for inversion of meso-parameters,and determining the values of various meso-parameters during simulation.(2)Carry out the biaxial loading simulation test of rock-fill samples with different particle gradations under four confining pressures(0.1MPa,0.2MPa,0.3MPa,0.4MPa),and obtain various rock-fill mechanical indexes,which are obtained through analysis The impact of the data research gradation on the macro-and meso-mechanical properties of rock-fill materials.It shows that as the content of fine particles in the sample taken increases,the particle breakage rate will be lower and the strength of the rock-fill sample will be higher.(3)Carry out biaxial loading simulation tests of rock-fill samples with different particle shapes(circular,pentagonal,and heptagonal)under four confining pressures.By analyzing the experimental results of stress-strain curve,particle displacement,force chain evolution,etc.The round particle sample has the highest strength,and the heptagonal particle sample has the lowest strength.Concentrated stress is likely to occur at the edges and corners of the particles to cause damage to the rock-fill sample.(4)Carry out the biaxial loading simulation test of rock-fill samples with different particle diameters(11mm,13 mm,15mm)under four confining pressures.From the stress-strain curve,it is found that when the particle size is too large or too small,the rock-fill test The strength of the sample will be reduced.The rock-fill sample with the middle particle size is the highest.The larger the particle size,the easier it is to damage the rock-fill.As the confining pressure increases,the strength of the rock-fill samples gradually increases. |
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