Table 3 Evaluation guidelines for safety evaluation indexes of metro shield construction in metro tunnels.

Human factors A₁

Age of construction workers

(year)B₁

[20,25]

[26,30]

[31,40]

[41,50]

[51,60]

Length of service of construction workers(year)B₂

[31,40]

[21,30]

[11,20]

[6,10]

[0,5]

Security awareness of personnel(score)B₃

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Security knowledge of personnel(score)B₄

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Operational skills of personnel(score)B₅

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Mechanical equipment factors A₂

Equipment Reliability (score)

B₆

[0,20]

Health

[20,40]

Basically

intact

[40,60]

Ordinary damage

[60,80]

Comparative damage

[80,100]

Severe

damage

Completeness of safety protection facilities(score)B₇

[1,2]

[3,8]

[9,16]

[18,25]

[30,36]

Maintenance of equipment B₈

[90,100]

Excellent

[75,89]

Good

[60,74]

Fair

[45,59]

Bad

[0,44]

Terrible

Environmental factors A₃

Hydrogeological factors

(score)B₉

[0,20]

No impact

[20,40]

Minor

impact

[40,60]

Moderate impact

[60,80]

Significant

impact

[80,100]

Severe

impact

Operating environment (score)B₁₀

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Construction surroundings

(score)B₁₁

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Climatic factors(score)B₁₂

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Management factors A₄

Safety education(score)B₁₃

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Safety Inspection(score)B₁₄

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Safety production responsibility

system(score)B₁₅

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

System implementation (score)B₁₆

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Contingency factors A₅

Emergency plan(score)B₁₇

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Emergency drill(score)B₁₈

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]

Emergency equipment and

materials(score)B₁₉

[0,20]

[20,40]

[40,60]

[60,80]

[80,100]