Study on Disease Mechanism and Theoretical Quantification Method of Tunnel Structure

Table 6

Evaluation criteria for corrosion of steel bars.

Structure	Main reason	Degree of corrosion	Rating status
Lining	Salt damage, water leakage, acid (alkali), etc.	Surface or small area corrosion	1
		Shallow hole corrosion or rebar rusted all around	2
		Steel section reduction is obvious, and steel structure engineering is damaged	3