Study on the Influence of Cracks on the Mechanical Performance of Tunnel Lining Structure Based on Fracture Mechanics Theory

Table 1

F and S_M values under pure bending.

Crack depth a (cm)	3	6	9	12	15	18
F	1.42	1.47	1.48	2.37	3.74	4.82
SM (m^−3/2)	16.3	23.9	29.5	54.6	96.3	135.9