The Application of Variable Fuzzy Sets Theory on the Quality Assessment of Surrounding Rocks

Table 1

The assessment standard of surrounding rock quality.

Level	(MPa)
I	250∼300	0.75∼1	9∼10	0∼5	80∼90
II	100∼250	0.55∼0.75	7∼9	5∼10	70∼80
III	50∼100	0.35∼0.55	4∼7	10∼25	30∼70
IV	25∼50	0.15∼0.35	2∼4	25∼125	10∼30
V	1∼25	0∼0.15	0∼2	125∼300	0∼10