粗粒土的粒间孔隙特征与其影响因素的相关性研究

Study on the correlation between intergranular pore characteristics and influencing factors of coarse grained soil

研究孔隙的形态、分布及孔隙特征的演化规律,对了解土体的力学性质具有重要的意义。采用离散元软件PFC2D模拟粗粒土的形成,并基于MATLAB数字图像处理技术,分析颗粒的接触刚度、粒间摩擦因数以及级配对粗粒土粒间孔隙特征参数的影响。研究结果表明:孔隙特征参数受颗粒接触刚度的影响不明显,不会由于接触刚度的变化而有较大改变。而孔隙率和平均等效直径会随着粒间摩擦因数的增加而呈现增大趋势,并且等效直径为1.5~3 mm的小孔隙占比减少,3~8 mm的大孔隙占比增多。不均匀系数和曲率系数对孔隙特征参数影响较明显,且各不相同,但都不是简单的线性影响。

The study of pore morphology and distribution is an important content in the study of soil meso structure. The influences of the particle stiffness, interparticle frictional coefficient and grading on the intergranular pore characteristics parameters of the coarse-grained soil were analyzed using the commercial software PFC2D to simulate the formation of coarse-grained soil and MATLAB for digital image processing. It is found that the impact which contact stiffness has on the pore characteristics parameters is not obvious, because pore characteristics parameters will not be changed too much due to the change of contact stiffness. While with the increase of the interparticle frictional coefficient, porosity and pore average equivalent diameter have a trend of increase. And the percentage of fine pore whose equivalent pore diameter is 1.5~3 mm decreases and the percentage of macro pore whose equivalent pore diameter is 3~8 mm increases. Uniformity coefficient and coefficient of curvature have obvious and different influences on pore characteristic parameters, but they are not simple linear influences.