冲击荷载下煤岩损伤演化规律

(1.西安科技大学 能源学院,陕西 西安 710054; 2.西安科技大学 西部矿井开采及灾害防治教育部重点实验室,陕西 西安 710054)

冲击荷载; 损伤演化; 超声波; 声发射; 动力灾害防控

Damage evolution of coal and rock under impact load
LAI Xing-ping1,2,FANG Xian-wei1,CUI Feng1,2,SHAN Peng-fei1,2

(1.College of Energy Science and Engineering,Xi'an University of Science and Technology,Xi'an 710054,China; 2.Key Laboratory of Western Mine Exploitation and Hazard Prevention,Ministry of Education,Xi'an University of Science and Technology,Xi'an 710054,China)

impact load; damage evolution; ultrasound; acoustic emission; dynamic disaster prevention and control

备注

冲击荷载下煤岩损伤演化规律的认识对动力学灾害防控至关重要。为了得到煤岩在冲击荷载下的损伤演化特征,通过开展冲击试验,运用超声波检测装置和声发射仪器分别测量冲击前后煤样的波速变化与冲击过程的声发射特征,用波速和声发射的变化反映煤样内部损伤特征。结果 表明:冲击荷载的作用次数、单次冲击能量的大小和施加顺序均会对煤样内部损伤演化造成影响; 煤样内部损伤随冲击次数增加呈幂函数增长,与单次冲击能量呈线性增长; 冲击能量由大到小进行施加更容易使煤样发生破坏。煤样内部损伤变化越剧烈,声发射信号特征越明显。用波速表征的煤样内部损伤变化与声发射在每个阶段监测到的事件数和能率变化有较好的一致性。这为矿井开采动力灾害预报与控制提供了科学依据。

It is very important for dynamic disaster prevention and control to know the damage evolution law of coal and rock under impact load.In order to explore the damage evolution characteristics of coal and rock under impact load,By carrying out impact tests,ultrasonic testing device and acoustic emission instrument were used to measure the wave velocity changes of coal samples before and after impact and the acoustic emission characteristics of the impact process respectively,and the wave velocity and acoustic emission changes were used to reflect the internal damage characteristics of coal samples; The results show that the impact times,the magnitude of single impact energy and the order of applying impact load will affect the internal damage evolution of the coal sample.The internal damage of coal sample increases with the impact times in a power function and linear with the single impact energy,The impact energy from large to small is more likely to cause the destruction of the coal sample,The more severe the internal damage changes,the more obvious the acoustic emission signal characteristics,The changes of internal damage of coal samples characterized by wave velocity are well consistent with the changes of event number and energy rate detected by acoustic emission in each stage,This provides a scientific basis for the prediction and control of dynamic disasters in mining.