摘要
煤层注水对预防煤与瓦斯突出、减尘降温和软化煤层卸压防冲均有显著作用。监测水体在煤层中的运移规律,获得有效的水力润湿范围对于评估煤体注水润湿效果十分必要,因此在真三轴状态下对煤体进行注水实验的同时,辅以超声波自激发技术监测记录不同注水条件下煤体透射超声波的特征参数,并对注水条件与纵波波速、幅度和衰减系数等特征参数的关系进行重点分析。结果表明:(1)注水量随注水压力增大不断增加并呈现线性稳定状态;但随着注水时间增加,注水量增速逐渐降低并趋于0。(2)超声波波速与注水压力呈线性正相关,且随注水压力增加波速增量基本稳定;波速与注水时间呈指数正相关,但对注水时间的敏感度逐渐减弱;探究并实现了注水煤体体积模量的波速表征。(3)随着注水压力增大,超声波幅值整体增大,衰减系数整体减小;超声波幅值和衰减系数对注水时间的敏感性均呈现低–高–低态势。(4)振铃计数等与注水压力均呈线性正相关,与注水时间均呈指数正相关,且与注水量的变化趋势具有较好的一致性。
Coal seam water injection has a significant effect on preventing coal and gas outburst,reducing dust and cooling,softening coal seam pressure relief and anti-scour.Monitoring the migration law of water in the coal seam and obtaining an effective hydraulic wetting range are very necessary to evaluate the wetting effect of coal water injection.Therefore,in this paper,the water injection experiment is carried out on the coal body under the true triaxial state,and the ultrasonic self-excitation is supplemented.Technical monitoring records the characteristic parameters of coal transmission ultrasonic wave under different water injection conditions,and analysis of the relationship between water injection conditions and characteristic parameters such as longitudinal wave velocity,amplitude and attenuation coefficient is carried out.The results show that:(1)The amount of water injection increases with the water injection pressure and presents a linear stable state,but as the water injection time increases,the growth rate of the water injection gradually decreases and tends to zero.(2)The ultrasonic wave velocity has a linear positive correlation with the water injection pressure,and the wave velocity increment is basically stable with the increase of the water injection pressure;the wave velocity has an exponential positive correlation with the water injection time,but the sensitivity to the water injection time is gradually weakened;Wave velocity characterization of bulk modulus.(3)With the increase of water injection pressure,the ultrasonic amplitude increases as a whole,and the attenuation coefficient decreases as a whole;the sensitivity of ultrasonic amplitude and attenuation coefficient to water injection time is low-high-low.(4)The ringing count and the like are linearly positively correlated with the water injection pressure,and have an exponential positive correlation with the water injection time,and have a good consistency with the changing trend of the water injection amount.
作者
王刚
李胜鹏
刘义鑫
冯净
李怀兴
WANG Gang;LI Shengpeng;LIU Yixin;FENG Jing;LI Huaixing(State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;College of Safety and Environmental Engineering,Shandong University of Science and Technology,Qingdao,Shandong 266590,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2022年第11期2225-2239,共15页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52174194,51974176)
山东省自然科学基金杰出青年基金项目(ZR2020JQ22)。
关键词
采矿工程
煤层注水
真三轴
超声波
煤体润湿
传播特性
波形参数
mining engineering
coal seam water injection
true triaxial
ultrasound
coal wetting
characteristics of propagation
parameters of waveform
