Mining Research Institute, Inner Mongolia University of Science and Technology
College of Energy and Mining Engineering,Shandong University of Science and Technology

Heilongjiang University of Science and Technology

水岩相互作用是地下采矿工程活动中的常见问题。为研究水岩作用下煤岩组合体的力学特性、损伤特征及劣化机制,对不同浸水时间下的细砂岩−煤 (FM)、粗砂岩−煤 (GM)、细砂岩−煤−粗砂岩(FMG)3 种组合体开展了轴向压缩试验。结果表明:①组合体含水率随浸水时间增加而增大,浸水20 d 以后达到饱水状态;5~15 d 为组合体的吸水区,15~20 d 为组合体近饱和区,20~25 d 为组合体的饱和区。②水岩作用下 3 种组合体的抗压强度、弹性模量、峰前能量、冲击能量指数等参数具有明显的劣化效应,其参数值均随浸水时间增加而减小;浸水 5~15 d 阶段为峰前能量陡降区,浸水 15~25 d 阶段为峰前能量缓降区;浸水时间 5~15 d,组合体冲击能量指数劣化明显,15 d 之后,劣化效应较弱;浸水 5~10 d 组合体为弱冲击倾向性,浸水 15~25 d 组合体无冲击倾向性。③随着浸水时间增加,组合体的声发射累积数显著下降。利用损伤理论构建了基于浸水时间的组合体损伤模型,该模型揭示了损伤变量与浸水时间的关系,反映了随着浸水时间增加,组合体的损伤程度增大的规律。④推导了类孔隙比计算公式,组合体的类孔隙比为:FM 组合体

Water-rock interaction is common seen in underground mining engineering activities. In order to study the mechanical properties, damage characteristics and deterioration mechanism of coal-rock combined samples under water-rock interaction, axial compressiontests were carried out on FM, GM and FMG combined samples under different immersion time. The main results are as follows: ①Watercontent of the sample increases with the increase of immersion time, and reaches saturated after 20, 5−15 is the water absorption period ofthe sample, 15−20 is the near-saturation period, and 20−25 is the saturation period.②The compressive strength, elastic modulus, pre-peakenergy and burst energy index of the three types of samples have obvious degradation effect under the interaction of water and rock, andthe parameter values decrease with the increase of immersion time. The steep drop region of pre-peak energy is observed in the 5−15 d ofimmersion, and the slow drop region of pre-peak energy is observed in the 15−25 d of immersion. Immersion time 5−15 d, the burst energy index deterioration is obvious, after 15 d, the deterioration effect is weak; Sample of immersion of 5−10 d is of weak burstproneness, Sample of immersion of 15−25 d is of no burst proneness.③With the increase of immersion time, the cumulative number ofacoustic emission of the sample decreases significantly. Based on the damage theory, the damage model of the sample with respect to immersion time was constructed. The model reveals the relationship between the damage variable and the immersion time, and reflects thebehavior that damage degree of the sample increases with the increase of the immersion time. ④The calculation formula of fake-void ratiois derived, and the fake-void ratio of the combined body is as follows: FM combined body < FMG combined body < GM combined body.The relationship between the fake-void ratio of composite and compressive strength was analyzed. the larger the fake-void ratio, the smaller the compressive strength. ⑤With respect to the deterioration effect, the deterioration mechanism of coal-rock combination under waterrock interaction was analyzed from physical, chemical and mechanical aspects.⑥The failure characteristics and deformation of coal-rockpillar under the influence of water in a coal mining area of Hegang mining area were analyzed. The strength and stability of coal-rock massunder the water-rock interaction have obvious deterioration effect, and this deterioration effect is more obvious at the early immersionstage. With the increase of immersion time, the deterioration effect is gradually weakened. This is consistent with the conclusions of thetests.

国家自然科学基金资助项目(51774122);内蒙古自治区自然科学基金资助项目(2020BS05007);内蒙古科技大学创新基金资助项目

陈光波, 李谭, 杨磊, 等. 水岩作用下煤岩组合体力学特性与损伤特征[J]. 煤炭科学技术, 2023, 51(4): 37-46.

CHEN Guangbo, LI Tan, YANG Lei. Mechanical properties and damage characteristics of coal-rock combined samples under water-rock interaction[J]. Coal Science and Technology, 2023, 51(4): 37-46.