Table 3 Parameters of CFST long pillars.

From: Research on the mechanism and technology of close range coal seam support and roof cutting collaborative lane control

Specimen number

Diameter/mm

Thickness/mm

Pillar length/mm

Length

Diameter ratio (L/D)

Radius

Thickness ratio (D/t)

Eccentricity (e/mm)

Yield strength/MPa

Concrete filled steel tube

SCL-1

83

5

1200

14.46

16.6

0

235

SCL-2

95

5

1200

12.63

19

0

235

SCL-3

108

5

1200

11.11

21.6

0

235

SCL-4

121

5

1200

9.92

24.2

0

235