Experimental Study on Comprehensive Real-Time Methods to Determine Geological Condition of Rock Mass along the Boreholes while Drilling in Underground Coal Mines

Table 5

Rock mass classification results of MWD and VMWD systems of cross-layer borehole No. 12.

Rock classification	The Id value divides the result	The RMS value divides the result
I	0∼4.2 m	0∼4.1 m
II	4.2 m∼13.2 m	4.1 m∼13.3 m
III	13.2 m∼18.1 m	13.3 m∼18 m
II	18.1 m∼20.7 m	18 m∼20.7 m
IV	20.7 m∼23.1 m	20.7 m∼23 m
III	23.1 m∼36.6 m	23 m∼36.5 m
IV	36.6 m∼41 m	36.5 m∼41 m