A Fuzzy Comprehensive Assessment Approach and Application of Rock Mass Cavability in Block Caving Mining

Table 2

The rock cavability classification based on the assessment approaches.

Assessment approaches	The ranks of cavability
	I	II	III	IV	V
RQD	90~100%	75~90%	50~75%	25~50%	0~25%
RMR	81~100	61~80	41~60	21~40	0~20
Q	>40	10~40	4~10	1~4	0~1
BQ	>550	451~550	351~450	251~350	0~250
FA	0.8~1.0	0.6~0.8	0.4~0.6	0.2~0.4	0~0.2
	0.9	0.7	0.5	0.3	0.1
	0.8~1.0	0.6~0.8	0.4~0.6	0.2~0.4	0~0.2