Research and Analysis on the Influence of Small Clear Distance Drilling and Blasting Method on the Existing Tunnel Structure

Table 3

Maximum closing speed of each monitoring point.

Excavation depth (m)	Resultant velocity (cm/s)
	191	1108	9851	970	487
54	2.27	3.87	1.68	0.49	0.35
60	2.54	3.91	3.61	0.83	0.35
78	1.39	2.94	11.28	3.11	1.15
84	0.82	1.78	10.72	3.49	1.67
90	0.68	1.29	5.89	3.31	1.97
Maximum	2.54	3.91	11.28	3.49	1.97