Table 2 Gas simulation parameters at different altitudes.

From: Study of harmful gas migration law and influencing factors after tunnel blasting in high-altitude tunnels under push ventilation conditions

Altitude/m

Atmospheric pressure/Pa

Temperature/K

Air density/kg m−3

CO density/kg m−3

CO initial mass fraction/%

0

101,325

288.2

1.22

1.18

0.209

1000

89,858

281.7

1.11

1.07

0.231

2000

79,467

275.2

1.00

0.97

0.255

3000

70,074

268.7

0.91

0.88

0.282

4000

61,602

262.2

0.82

0.79

0.313

5000

53,981

255.7

0.73

0.71

0.348

6000

47,143

249.2

0.66

0.64

0.389