Experimental Study on the Mechanics Characteristics of CFRP Strengthening of Highway Tunnels at Different Damage States

Table 2

Definitions of several physical quantities used in the paper.

Symbol	Definition	Unit
	Strengthening load	kPa
	Cracking load	kPa
	Failure load of an unstrengthened lining	kPa
	Failure load of a strengthened lining	kPa
	Stiffness of an unstrengthened lining at stage I before cracking, as shown in Figure 7	kPa/mm
	Stiffness of an unstrengthened lining at stage II after cracking, as shown in Figure 7	kPa/mm
	Stiffness of a strengthened lining at the compatible deformation stage, as shown in Figure 8	kPa/mm
	Stiffness of a strengthened lining at the rapid deformation stage, as shown in Figure 8	kPa/mm
	Vault settlement during failure	mm
	Sidewall convergence during failure	mm