LAUSR

The mechanical properties of cemented paste backfill (CPB) depend heavily on its pore structural characteristics and micro-structural changes. In order to explore the variation mechanisms of macro-mechanical characteristics and micro-structure of CPB. CPB specimens with different mass concentrations prepared from the full tailings of Xianglushan Tungsten Ore were micro-tests. Moreover, acquired pore digital images were processed by using the pores (particles) and cracks analysis system (PCAS), and a sensitivity analysis was performed. The results show that as the mass concentration of CPB increases from 70% to 78%, the porosity, the average pore area and the number of pores drop overall, leading to a decline in the pores opening degree and enhancing the mechanical characteristics. As the mass concentration of CPB increases, the trend of fractal dimension, probability entropy and roundness is reduced, constant and increased, which can result in an enhancement of the uniformity, an unchanged directionality and more round pores. According to the definition of sensitivity, the sensitivities of various micro-parameters were calculated and can be ranked as porosity > average pore area > number of pores > roundness > fractal dimension > probability entropy. 胶结充填体的力学性能很大程度上取决于其孔隙结构特征及微观结构的变化. 为探究胶结充填体的宏观力学特性和微观结构的变化机理, 以香炉山钨矿的全尾砂为试验材料, 通过对不同质量浓度的胶结充填体开展微观试验, 获得的孔隙数字图像采用颗粒及孔隙识别与分析系统(PCAS)进行处理并进行敏感度分析. 结果表明: 随着胶结充填体质量浓度的增大(由70%增大到78%), 孔隙率、平均孔隙面积、孔隙数的总体变化趋势减小, 导致孔隙张开的程度变小使其力学特征增强; 随着胶结充填体的质量浓度对分形维数、概率熵和圆形度总体的趋势是减小、不变和增大导致均一化程度提高、定向性保持不变和孔隙更接近圆形. 按照敏感度的定义, 计算微观参数敏感度, 其敏感度排序为孔隙率>平均孔隙面积>孔隙数>圆形度>分形维数>概率熵.