Table 6 Classification of hazardous gas B5.

From: Safety risk assessment of weak tunnel construction with rich groundwater using an improved weighting cloud model

 

Level I

Level II

Level III

Level IV

Level V

Hazardous gas (Gas pressure) /MPa

< 0.35

0.35–0.45

0.46–0.55

0.56–0.74

≥ 0.74

  1. In this study, the gas pressure measuring instrument is used for measurement.
Back to article page