摘要
自主搭建煤体自振频率测试系统,利用敲击法测试原煤试件干燥前后的加速度响应特征,通过其频谱特征分析水分对原煤自振频率的影响规律。研究发现:随着含水量的增加,煤岩刚度下降,质量增加,阻尼比增加,自振频率有明显下降的趋势(从40.1 Hz下降至37.7 Hz);原煤试件干燥前的主振频域为29.9~45.4 Hz,干燥后的主振频域为31.6~49 Hz;原煤试件干燥前的主振频域上、下限值与自振频率的绝对偏差比例分别为20.8%和20.4%,干燥后的比例分别为21.1%和22.1%,均满足产生共振效应的频域条件。应关注水分对现场煤岩体自振频率的影响,以保证共振调控措施的效果。
By establishing a self-vibration frequency test system,the resonance response method was used to test the acceleration response characteristics of raw coal specimens before and after drying.Then the influence of moisture on the natural vibration frequency of raw coal was analyzed by its spectral characteristics.The study found that:with the increase of water content,the stiffness of coal rock decreased,the mass increased,the damping ratio increased,and the natural vibration frequency decreased significantly(from 40.1 Hz to 37.7 Hz).The main vibration frequency domain of the raw coal specimen before drying was 29.9 Hz to 45.4 Hz,and the main vibration frequency domain after drying was 31.6 Hz to 49 Hz.The absolute deviation ratios of the upper and lower limits of the main vibration frequency domain and the natural vibration frequency before the drying of the original coal specimens were 20.8% and 20.4%,respectively,and the ratios after drying were 21.1% and 22.1%,respectively,which satisfied the frequency domain conditions for generating resonance effects.We should pay attention to the influence of moisture on the natural vibration frequency of the on-site coal and rock mass to ensure the effect of resonance control measures.The obtained results contribute to improve the resonance and prevention mechanisms of coal and gas outburst.
作者
张苏
王金贵
ZHANG Su;WANG Jingui(College of Environment and Resources,Fuzhou University,Fuzhou 350116,China)
出处
《煤矿安全》
CAS
北大核心
2019年第12期6-9,共4页
Safety in Coal Mines
基金
福建省教育厅科研资助项目（JAT170057）
国家自然科学基金资助项目（51704079,51604083）
福州大学贵重仪器设备开放测试基金资助项目（2019T007）
关键词
水分
侵蚀
煤岩
自振频率
共振
煤岩动力灾害
moisture
erosion
coal rock
natural vibration frequency
resonance
coal and rock dynamic disasters
