Table 2.

Basic physical parameters of samples with different depths.

Drilling depth (m)	Average diameter (mm)	Average height (mm)	Average mass (g)	Moisture content (%)	Saturated water absorption (%)	Total porosity (%)	Longitudinal wave velocity (ms−1)
100	50.04	100.41	467.1	0.091	0.342	0.851	3535.56
200	50.42	99.98	468.49	0.089	0.345	0.843	3447.33
300	50.58	99.91	471.97	0.092	0.341	0.847	3362.63
400	50.37	100.23	480.49	0.091	0.345	0.862	3457.84
500	50.41	100.13	482.09	0.087	0.337	0.856	3653.88
600	50.94	99.94	463.9	0.088	0.338	0.860	3460.75