Table 1 Ultrasonic test results.

From: Research on dust and rockburst control technology for coal mining and mathematical correlation

Coal sample number

Vp(m·s-1)

Vs(m·s-1)

Vp/Vs

1#

1232

725

1.699

2#

1218

731

1.666

3#

1221

733

1.665

4#

1240

719

1.723

5#

1248

729

1.712

6#

1251

723

1.730