冷冲击条件下饱水煤样结构损伤规律研究  

Research on structural damage law of water-saturated coal sample under cold shock conditions

作　　者：戎彦龙 王毅 赵东 赵耀江[1] 游世达 郭志 RONG Yanlong;WANG Yi;ZHAO Dong;ZHAO Yaojiang;YOU Shida;GUO Zhi(College of Safety and Emergency Management Engineering,Taiyuan University of Technology,Jinzhong Shanxi 030600,China;Key Laboratory of In-situ Property-improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan Shanxi 030024,China)

机构地区：[1]太原理工大学安全与应急管理工程学院,山西晋中030600 [2]太原理工大学原位改性采矿教育部重点实验室,山西太原030024

出　　处：《中国安全生产科学技术》2022年第10期86-93,共8页Journal of Safety Science and Technology

基　　金：国家自然科学基金项目(51904197);山西省自然科学基金项目(201801D121283)。

摘　　要：为探究煤体在冷冲击影响下强度损伤特征及细观结构演化规律,通过自制低温冲击系统,利用声发射、金相显微镜宏观与细观手段结合的方法,基于ImageJ图像分析软件分别对干燥煤样、饱水煤样冷冲击前后细观结构演化进行量化表征,并通过测试渗透率验证煤体结构变化带来的增透效果,研究结果表明:在煤体中超声波波速随冷冲击温度降低而下降;相同时间内,冷冲击温度越低,声发射振铃计数表现越活跃,煤体释放能量愈大,致裂效果越显著;经冷冲击后的饱水煤样相对于干燥煤样会产生更多的斜向新生裂隙,新萌生裂隙与原生裂隙交汇贯通形成絮状网格,其渗透效果显著提升;随冲击温度的降低,抗压强度、弹性模量均增大。研究结果可为低温改善煤层透气性,增产煤层气及矿井瓦斯灾害防治技术提供理论依据。In order to explore the characteristics of strength damage and microstructure evolution of coal under the influence of cold shock,through the self-made low temperature shock system,the method combining the macroscopic and microscopic methods of acoustic emission and metallographic microscope was used.Based on the ImageJ image analysis software,the microstructure evolution of dried and water-saturated coal samples before and after cold shock was quantitatively characterized,and the permeability was tested to verify the permeability enhancement effect brought by the change of coal structure.The research results showed that the ultrasonic wave velocity decreased with the decrease of cold shock temperature in the coal.Within the same time,the lower the cold shock temperature,the more active the acoustic emission ringing count,the greater the energy released by the coal,and the more significant the fracturing effect.Compared with the dried coal sample,the water-saturated coal sample after cold shock would produce more oblique new cracks,and the new cracks intersected with the original cracks to form a flocculent grid,its permeation effect was significantly improved.With the decrease of shock temperature,both the compressive strength and elastic modulus increased.The results can provide theoretical basis for the technologies improving the coal seam permeability,increasing the coalbed methane production and the prevention and control of mine gas disaster at low temperature.

关 键 词：冷冲击 饱水 金相显微镜 声发射 热应力 

分 类 号：X936[环境科学与工程—安全科学] TD712[矿业工程—矿井通风与安全]