堆石料双轴试验数值模拟研究

颗粒形状对堆石料的力学特性有着明显的影响。采用二维颗粒流程序建立5种不同形状特征的颗粒簇,开展了不同围压下堆石料的双轴试验的数值模拟研究,分析了不同形状特征对堆石料的破碎特性及其宏观力学性质的影响。分析过程中考虑堆石料的颗粒破碎特征,对布拉斯谢克形状系数s进行修正,提出了考虑颗粒形状特征的修正系数s′。研究结果表明:堆石料的破碎率随着修正后的形状系数s′值的增加而减少,其规律接近于反比例函数线;数值模拟过程中,5种试样随着轴向应变的增加呈先剪胀后剪缩的趋势,且越圆润的颗粒峰值体应变越大;材料的峰值强度随着s值的增大而增大。

Effect of Particle Shape on Simulating Particle Breakage of Rockfill by Biaxial Tests

The shapes have a great influence on the mechanical property of rockfill.In order to research the effect on breakage and macro mechanics property of rockfill,the writers use particle flow code technology to create five different specimens of clusters to simulate the biaxial tests under three confining stresses.At the same time the shape factor is introduced to qualify the five clusters.The result shows that with the increase of the values of s′,the percentage of breakage has a decreasing trend and the fitting curve is like a inverse proportion function line.Based on the numerical simulation,it shows that the five modeling materials all have shear dilatation first and shear contraction later,and the more circular the shape is,the greater volume strain modeling materials would have.The peak strength of the material contrast is monotonically increasing with the increase of values s.