Application of Impact Imaging Method on Nondestructive Detection of Void Defects in Sandwich-Structured Immersed Tunnel

Table 5

Location numbers where the waveform data were extracted from the measuring points.

Points	Distance from T-stiffener (cm)	Filling situation	Void height (mm)	Points	Distance from T-stiffener (cm)	Filling situation	Void height (mm)
a1	10	Dense	0	b1	10	Void	6
a2	5	Dense	0	b2	5	Void	12