卸荷条件下含瓦斯煤声发射临界慢化特征  

Critical slowing down characteristics of acoustic emission of gas bearing coal under unloading conditions

作　　者：张冉 刘杰[1] 撒占友[1] 程健维[2] 卢守青[1] 王春源[1] ZHANG Ran;LIU Jie;SA Zhanyou;CHENG Jianwei;LU Shouqing;WANG Chunyuan(Department of Safety Science and Engineering,Qingdao University of Technology,Qingdao Shandong 266520,China;School of Safety Engineering,China University of Mining and Technology,Xuzhou Jiangsu 221116,China)

机构地区：[1]青岛理工大学安全科学与工程系,山东青岛266520 [2]中国矿业大学安全工程学院,江苏徐州221116

出　　处：《中国安全科学学报》2021年第9期128-134,共7页China Safety Science Journal

基　　金：国家自然科学基金资助(51974169,51574153,51804176);中国博士后科学基金资助(2018M642632);山东省重点研发计划项目(2018GSF120012);山东省自然科学基金资助(ZR2018PEE001)。

摘　　要：为得到煤样在卸荷条件下失稳破坏的有效前兆信息,设计不同瓦斯压力下的固定轴压卸围压试验,得到煤样破裂过程的声发射(AE)结果,并计算得到不同瓦斯压力条件下AE时间序列的临界慢化特征,预警煤岩瓦斯动力灾害的发生。研究结果表明:卸荷条件下含瓦斯煤AE时间序列具有临界慢化特征,方差与自相关系数在煤样破坏前的突然增大可以作为表征试样破裂失稳的前兆信息;窗口长度与滞后步长会对临界慢化特征产生影响,相比之下,方差受窗口长度和滞后步长影响均较小,且前兆信息出现前曲线变化波动平稳。In order to obtain effective precursor information of instability failure of coal sample under unloading conditions, a fixed axial stress unloading confining stress experiment under different gas pressures was designed,and AE results of coal sample fracture process were obtained,and critical slowing down characteristics of AE time series under different gas pressures were calculated,so as to provide early warning of occurrence of coal and rock gas dynamic disasters. The results show that under unloading conditions,AE time series of gas-bearing coal has critical slowing characteristics. Sudden increase of variance and autocorrelation coefficient before coal sample failure can be used as precursor information to characterize failure of sample. Window length and lag step can affect critical slowing down characteristics.In contrast,variance is less affected by window length and lag step,and curve changes smoothly before precursor information appears.

关 键 词：卸荷条件 含瓦斯煤 声发射(AE) 临界慢化特征 前兆信息 

分 类 号：X936[环境科学与工程—安全科学]