考虑颗粒级配效应的砂土剪切强度

Effect of particle size distribution on the shear strength

为了研究颗粒级配对砂土剪切强度的影响,以室内直剪试验和二维离散元数值模拟为基本方法,研究了砂土颗粒级配和大小对其剪切强度的影响。通过制备15种不同级配的室内剪切试样和15种离散元数值剪切试样,在标定微观参数的基础上,同时进行了室内试验和离散元数值模拟,结果表明:曲率系数和不均匀系数对砂土剪切强度影响很明显。粒径d10、d30、d60对内摩擦角分别有着明显的影响作用,尤其是d10对其影响最为显著。数值试验结果表明,试样在剪切过程中颗粒级配对于孔隙率、配位数以及局部剪应力都有一定的影响作用,而细小颗粒所占的比例起着主导作用。

Based on indoor direct shear test and two-dimensional discrete element numerical simula- tion, the effect of particle size on the shear strength of sand is studied. Fifteen kinds of different gradation of the indoor shear specimens and 15 kinds of discrete element numerical shear specimen are prepared on the ba- sis of the microscopic parameters of the calibration, and the indoor experiment and discrete element numerical simulation. The results show that： coefficient of curvature and uneven coefficient of shear strength of sand effect is obvious. Particle size dlo, d3o, dro has a significant impact on the internal friction angle, especially the dl0 has the most significant influence on the internal friction angle. The numerical results show that the particle size distribution has a certain effect on the porosity, the coordination number and the local shear stress in the shear process, and the proportion of small particles plays a leading role.