Study on the Correlation of Vibration Properties and Crack Index in the Health Assessment of Tunnel Lining

Table 2

Tunnel-lining crack index of the ten studied spans.

Span number
1	4.644	12.709	17.353
12	1.964	1.969	3.933
16	1.837	0.203	2.040
18	1.179	1.466	2.645
20	3.885	0.278	4.163
35	0.321	1.569	1.890
42	3.470	6.580	10.050
49	19.000	21.281	40.281
58	20.937	9.705	30.642
65	13.995	12.122	26.117