不同黏结剂配比条件下型煤力学及渗透特性试验研究

利用含瓦斯煤热-流-固耦合三轴伺服渗流装置，为使得型煤力学及渗透特性更接近原煤，选取水泥作为黏结剂，进行了不同黏结剂配比条件下的型煤和原煤三轴压缩试验对比研究。基于欧式距离的相似性度量方法对能反映型煤的力学及渗透特性的特征值指标进行定量评价。结果表明：随黏结剂含量的增加，型煤的峰值主应力差、弹性模量近乎呈正指数函数递增趋势，泊松比呈负指数函数递减趋势；随着黏结剂含量的增加，型煤的初始渗透率、最小渗透率基本呈负指数函数递减趋势，且其渗透率变化率随黏结剂含量的增加越来越小，表现为渗透率-轴向应变曲线越来越平缓；基于欧式距离的相似性度量方法得出水泥黏结剂配比为IV型的型煤在力学及渗透特性方面与原煤最为接近，可以作为模拟原煤的相似材料。

Experimental study of mechanical and permeability characteristics of moulded coals with different binder ratios

This paper attempts to make mechanical and permeability characteristics of cement bound coals closer to those of undisturbed coals. It uses triaxial servo-controlled seepage equipment for thermo-fluid-solid coupling of coal containing methane and selects cement as a binder. The triaxal compressive properties of cement bound coals with different binder ratios are compared with those of undisturbed coals. The characteristic values for the mechanical and permeability characteristics of the cement bound coals are evaluated quantitatively using Euclidean distance based similarity methods. The results show that: as binder ratios increase, the peak principal stress difference and the elastic modulus of the cement bound coal probably increase following a positive exponential function trend. Poisson''s ratio decreases following a negative exponent function trend. As the binder ratio increases, the initial permeability and the minimum permeability of the cement bound coal have the decreasing trend of exponent function. The penetration rate of change is smaller and smaller. The permeability-axial strain curve is gentler. The mechanical and permeability characteristics of the cement bound coal with the cement binder ratio #IV are the closest to those of undisturbed coal. This type of cement bound coal can be used as the similar material for simulating the undisturbed coal.