College of Safety and Emergency Management Engineering, Taiyuan University of Technology

为探究饱水煤体在冷热冲击下的损伤特性,使用高低温试验箱对煤样进行不同温差的冷热冲击,冲击过程中利用声发射仪从微观尺度监测煤体损伤,利用金相显微镜从细观尺度观察冲击前后煤体表面的裂隙变化,并从微观尺度与细观尺度解释了冷热冲击后煤体的单轴抗压强度和渗透率的宏观变化。试验结果表明:经冷热冲击后的饱水煤样表面裂隙数目增多,各裂隙相互连接贯通,同一区域内裂隙面积增大;冷热冲击温差越大,声发射信号越活跃,致裂效果越显著,宏观表现为煤体的抗压强度越小,其渗透率增大。

In order to explore the damage characteristics of water - saturated coal under thermal shock, a high and low temperature test chamber was used to treat the coal samples with different temperature differences. The microscopic observation of the changes of the fissures on the coal surface before and after the shock was carried out from the microscopic scale, and the macroscopic changes of the uniaxial compressive strength and permeability of the coal body after the thermal shock were explained through the microscopic and mesoscopic scales. The test results show that the number of cracks on the surface of the water-saturated coal sample after cold shock and heat shock increases, and the cracks are connected to each other, and the crack area in the same area increases; the more significant the effect is, the smaller the compressive strength of the coal body is, and the higher its permeability is.

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

郭 志, 王 毅, 戎彦龙. 冷热冲击饱水煤体多尺度损伤特性研究 [J]. 煤炭工程, 2023, 55(7): 133-138.