School of Energy Science and Engineering,Henan Polytechnic University

目前,巷道煤层注水是预防综放开采煤岩体冲击地压的有效技术措施之一。利用义马矿区耿村煤矿综放工作面煤样,在室内进行煤样吸水性试验后,制作成不同含水率的圆柱形煤样,进行霍普金森(SHPB)单轴冲击试验,研究冲击速度和含水率对煤样动态力学性质的影响。结果表明:(1)煤样含水率与浸水时间呈正相关。按照含水率-浸水时间曲线拐点,将煤样浸水过程划分为2个阶段即前期浸水和后期浸水阶段。(2)煤样动态力学参数均与煤样冲击速度和含水率有关。当煤样含水率一定时,随着冲击速度增大,煤样动态抗压强度和动态弹性模量均与冲击速度呈正相关;当煤样冲击速度一定时,随着含水率升高,煤样动态抗压强度和动态弹性模量均与含水率呈负相关。(3)根据屈服强度和峰值强度,将煤样单轴动态应力-应变全过程划分为3个变形阶段即弹性阶段、屈服阶段和应变软化阶段,回归出煤样各阶段应力-应变拟合方程。研究结果可为冲击地压矿井深孔煤层注水防冲措施的实施和应用提供参考。

At present,coal seam water injection in gateway is one of the effective technical measures to pre‑vent coal bumps in longwall top coal caving mining. Raw coal samples were selected in the coal face of Geng Village in Yima mining area,China.The water absorption tests of coal specimens were carried out at laboratory,then cylindrical specimens with different moisture contents were made. The Hopkinson(SHPB)uniaxial impact compression tests were carried out to study the influence of impact velocity and moisture content of specimens on their dynamic mechanical properties.The test results showed that:(1)The moisture content of specimens was positively correlated with their soaking time.Bound on the inflection points of wa‑ter content-soaking time curve,the soaking process of specimens was divided into two stages,namely the early soaking stage and the late soaking stage.(2)The dynamic mechanical parameters of specimens were re‑lated to their impact velocities and moisture content.While the moisture content of specimens was constant,dynamic compressive strength and dynamic elastic modulus were positively correlated with their impact ve‑locity.While the impact velocity of specimens was constant,dynamic compressive strength and dynamic elas‑tic modulus were negatively correlated with their moisture contents.(3)According to the yield strength and peak strength of specimens,the whole uniaxial dynamic stress-strain process of the specimens was divided into three deformation stages,namely,the elastic stage,the yield stage,and the strain softening stage. The stress-strain fitting equation for each stage of the specimens was regressed.The conclusions could provide reference for the implementation and application of the measures of coal seam water injection by deep bore‑holes to prevent coal bumps in coal mines.

国家自然科学基金资助项目(52074102,52109081)

0 引言
1 煤样采集及其物理力学性能
2 含水煤样单轴冲击试验
2.1 SHPB试验
2.2 煤样吸水性试验
2.3 含水煤样制作
3 含水煤样SPHB试验结果
4 含水煤样SPHB试验结果与分析
4.1 峰值应变率与冲击速度关系
4.2 动态单轴抗压强度特征
4.3 动态弹性模量特征
4.4 煤样动态残余应变特征
5 讨论
6 结论

翟新献,刘勤裕,赵晓凡,等 . 不同含水率煤样单轴冲击力学性质试验研究[J]. 河南理工大学学报(自然科学版),2023,42(5):18-28.doi:10.16186/j.cnki.1673-9787.2021120121

ZHAI X X,LIU Q Y,ZHAO X F,et al.Experimental study on mechanical properties of coal specimens with different moisture contents under uniaxial impact[J].Journal of Henan Polytechnic University(Natural Science),2023,42(5):18-28.doi:10.16186/j.cnki.1673-9787.2021120121