Table 12 Classification of safety management B10.

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

On-site management (%)

> 98

95–98

92–95

88–92

≤ 88

Monitoring (times/d)

> 4

3

2

1

0

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