含瓦斯煤破裂过程中声发射行为特性的研究  

Investigation on acoustic emission characteristics in failure process of coal absorbed methane

作　　者：孟磊[1,2] 王宏伟[2] 李学华[2] 赵毅鑫[1,2] 

机构地区：[1]中国矿业大学(北京)煤炭资源与安全开采国家重点实验室,北京100083 [2]中国矿业大学(北京)力学与建筑工程学院,北京100083

出　　处：《煤炭学报》2014年第2期377-383,共7页Journal of China Coal Society

基　　金：国家重点基础研究发展计划(973)资助项目(2010CB226804);国家自然科学基金资助项目(51174213);煤炭资源与安全开采国家重点实验室开放课题资助项目(SKLCRSM13KFB10)

摘　　要：为探求含瓦斯煤失稳破坏过程中的声发射行为演化规律,笔者以含瓦斯原煤为研究对象,利用配备有声发射同步监测功能的含瓦斯煤三轴力学伺服实验装置,完成了不同瓦斯压力条件下含瓦斯煤破裂过程中全应力应变和声发射行为同步监测实验,进而探求含瓦斯煤破裂过程中的声发射行为演化特性,以及声发射行为对瓦斯压力变化的响应特性。研究发现:含瓦斯煤弹性模量、峰值强度及峰值应变均随吸附瓦斯压力增加而线性降低,且在瓦斯压力的影响下应力应变曲线总体上向"低应力诱发大应变"方向迁移;受载煤体在破裂过程中随时间变化,声发射行为演化过程可以划分为4个时期,分别为Ⅰ平静期、Ⅱ提速期、Ⅲ加速期以及Ⅳ稳定期,其中提速期和加速期累计计数较平静期分别最高提高了6.39和37.5倍,能量参数分别最高提高了8.39和43.7倍;受载不含瓦斯煤样声发射演化过程中提速期和加速期的声发射参数累积量均明显高于同样加载条件下的含瓦斯样品,且在提速期和加速期,瓦斯压力与声发射参数累积量呈指数函数衰减关系。In order to acquire the evolution characteristics of acoustic emission in failure process of coal absorbed methane, the raw coal absorbed gas was used as the object of study in this paper and the acoustic emission behavior evolution characteristics in failure process of coal absorbed gas under different pore pressure was performed by using triaxial servo-controlled press equipment with acoustic emission synchronous detection function for coal absorbed gas. The results show as follows： mechanical parameters of the coal absorbed gas such as elastic modulus, peak strength and peak strain decrease as increase of gas pressure, and the stress-strain curve transfers to＂ large strain induced by low stress＂ under the influence of gas ; the acoustic emission behavior evolution of coal can be divided into four phases with time, including quiet period, slow acceleration period, acceleration period and stationary period;cumulative ring counts of slow acceleration and acceleration period increases respectively 6.39 and 37.5 times in comparison with quiet period, and energy parameters increases respectively 8.39 and 43.7 times in comparison with quiet period ; the acoustic emission parameters of slow acceleration period and acceleration period in failure process of coal mass under load are obviously higher than coal mass absorbed gas under the same conditions, in addition, the acoustic emission parameters have exponential attenuation relationships with gas pressure in the acceleration period.

关 键 词：含瓦斯煤 声发射 时空演化 损伤破坏 

分 类 号：TD315[矿业工程—矿井建设] TD712