摘要
为研究低频机械振动频率对煤体瓦斯含量的影响,建立孔隙瓦斯压力、吸附膨胀力、机械挤压应力作用下振动动态煤体瓦斯含量方程。利用瓦斯吸附/解吸激振与测试系统进行振动未吸附饱和型煤试件试验检验方程,结果显示:振动频率相同,振动时间增加,煤体孔隙增多,煤体内部游离瓦斯增多,瓦斯含量变大;振动时间相同,振动频率越大,煤体孔隙率越大,煤体瓦斯含量越大,且20 Hz与10 Hz含量差值由小变大,30 Hz与20 Hz含量差值由大变小。表明振动增大了煤体孔隙率,使煤体瓦斯含量增加,且振动频率从10,20,30 Hz逐渐增加,孔隙率逐渐变大,煤体瓦斯含量相应变大,方程计算值能较好反应不同振动频率、振动时间作用下煤体瓦斯含量变化规律。
To study the effect of low-frequency disturbance load on gas volume, a formula for gas content considering coal porosity pressure, absorption strength and decreasing vibration stress is established. Meanwhile, the absorption capacity formula is verified by using vibrating and absorption instruments. The tests indicate that under the constant vibrating frequency, when the vibration time extends, the porosity and free-state gas increase, so gas content increases. Under the constant vibrating time, when the frequency speeds up, the porosity expands and gas content increases. Under frequency of 20 Hz and 10 Hz, D-value of content moves up, while under frequency of 30 Hz and 20 Hz, D-value of content moves down. The vibration expands the porosity inside the samples, thereby the gas content accumulated. When the frequency moves up to 10, 20 and 30 Hz, the porosity expands and the gas content is accelerates accordingly. The proposed formula significantly reveals the change law of gas content under different frequencies and time ranges.
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2015年第5期918-923,共6页
Chinese Journal of Geotechnical Engineering
基金
国家自然科学基金项目(51174157)
国家自然科学基金科学仪器基础研究专款项目(51327007)
关键词
低频机械振动
振动频率
振动时间
孔隙率
瓦斯含量
low frequency vibration
vibrating frequency
vibrating time
porosity
gas content
