An Experiment Monitoring Signals of Coal Bed Simulation under Forced Vibration Conditions

Table 2

Material and mixing ratio.

	Cement	Lime	Coal powder	Medium sand	Gravel	Water
Coal floor	1	—	—	1.65	2.8	0.55
Coal bed	1	4	20	—	—	6
Coal roof	1	—	—	6.9	—	1.6