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在基于CT扫描的不规则颗粒三维离散元精细建模技术的基础上,提出了一种不规则块石三维离散元模型随机生成技术,并建立了符合宏观统计规律的土石混合体三维离散元模型。进行了含石量为0,10%,30%,50%,70%,90%的土石混合体大三轴试验数值模拟研究,对各种含石量下土石混合体的力学特性和变形破坏机理进行了深入地分析探讨。结果表明:随着含石量的增加,试样峰值强度、残余强度、弹性模量和破坏应变逐渐增大,剪缩性减小,剪胀性增强;加载初期,微裂纹主要在块石颗粒与土颗粒之间形成,发展速度很快,而后则主要在土颗粒间形成和扩展,含石量越大,块石周围微裂纹比例越高,局部剪切带越不规则,分布也越分散;高含石量(70%,90%)的土石混合体在加载初期即有比较明显的相互摩擦,随后块石相互接触、咬合与相对摩擦、滑移交替出现。
Based on the fine modeling technique of irregular granular 3D discrete element based on CT scanning, a random three-dimensional discrete element model generation method of irregular block stone was proposed and a three-dimensional discrete element model of soil-stone mixture . The large-scale triaxial tests of rock-soil mixture with 0, 10%, 30%, 50%, 70% and 90% of rock mass were carried out. The mechanical properties and deformation failure Mechanism of in-depth analysis and discussion. The results show that with the increase of rock content, the peak strength, residual strength, elastic modulus and failure strain gradually increase, the shear shrinkage decreases and the dilatancy increases. At the initial stage of loading, And soil particles formed between the rapid development, and then mainly in the formation and expansion of soil particles, the greater the amount of stone, the higher the proportion of microcracks around the rock, the more irregular local shear bands, the more dispersed the distribution (70%, 90%) of soil-rock mixture at the initial stage of loading that is more obvious mutual friction, followed by block stone contact with each other, occlusal and relative friction, slip alternately.