Table 1 Physical and Mechanical Parameters of Overlying Strata on 12,240 Working Face.

From: Overlying strata movement law and rockburst prevention & control for fully mechanized top coal caving face in extra-thick coal seams

Lithology

density

/kg.m -3

Bulk modulus/GPa

Cut

Modulus

/GPa

Tensile strength/MPa

Poisson’s ratio

Internal friction angle/°

Cohesion

/MPa

2–3 coal

1344

1.6

1.4

0.4

0.25

30

2.08

Sandy

Mudstone

2550

12.1

9.5

2.6

0.26

37

4.66

Fine sandstone

2650

16.3

12.5

4.3

0.30

38

7.50

Medium sandstone

2600

13.5

10.1

3.0

0.24

35

5.00

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