Evaluation Method of Floor Heave Damage Degree and a Case Study in Zaoquan Coal Mine, China

Table 1

Damage degree of floor heave corresponding to different acoustic wave velocities [7].

Wave velocity of surrounding rock V (m·s^−1)	0∼2000	2000∼2500	2500∼4000	4000∼5000	5000∼7500
Qualitative description of floor rock	Extremely broken	Very broken	Severe broken	Relatively complete	Very complete