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块石形态是影响土石混合体细观结构及宏细观力学特性的一个重要因素。提出一种基于真实块石形态的土石混合体细观力学研究方法,首先采用三维扫描技术建立块石三维形态数据库,然后根据粒度组成生成试样内部块石三维空间分布模型,从而构建土石混合体的数字模型。利用所提出的基于多球颗粒均匀接触的复杂块体表征算法,实现任意复杂形态块体的多球颗粒均匀、紧密接触填充。基于上述方法,建立土石混合体离散元数值计算分析模型,并协同现场试验结果开展三维数值直剪试验研究。根据土体的现场试验结果反演得到离散元数值试验中土颗粒的细观接触力学参数,将其应用于土石混合体数值试验得到了较好的效果。通过数值试验研究表明,土石混合体在剪切过程中的块石效应,使剪切带变得更加宽厚和曲折,在宏观上造成了试样的内摩擦角有增高趋势;而由于块石含量增加,使得其黏结作用的土体含量减小,从而在宏观上表现为试样黏聚力呈略有降低趋势。
Rock morphology is an important factor that influences the meso-structure and macro-meso-mechanical properties of soil-rock mixture. In this paper, a method of meso-mechanics of rock and soil mixture based on real rock morphology is proposed. Firstly, three-dimensional scanning technique is used to build the three-dimensional database of rock and stone, and then the three-dimensional spatial distribution model of rock mass is generated according to the granularity, Digital model. By using the proposed complex block characterization algorithm based on uniform contact of multi-spherical particles, uniform and close contact filling of multi-spherical particles in any complex morphology block can be achieved. Based on the above method, the discrete element numerical analysis model of soil-rock mixture is established and the three-dimensional numerical direct shear test is carried out with the field test results. According to the field test results of soil, the mesoscopic contact mechanics parameters of soil particles in the discrete element numerical test are obtained. The numerical results show that the method has good effect. The results of numerical experiments show that the rock-stone effect during the shearing process of rock-soil mixture increases the shear band width and zigzag, which leads to an increase of the internal friction angle of the sample. However, Increase, making the bonding of the role of the soil content decreases, which macroscopically showed a slight decrease in the cohesion of the sample.