Hollow Effect of Ground Vibration Induced by Electronic Detonator in Shallow Tunnel

Table 3

Averages and standard deviations of dominant frequency.

Monitoring distance (m)	X-axis average (Hz)	X-axis standard deviation	Y-axis average (Hz)	Y-axis standard deviation	Z-axis average (Hz)	Z-axis standard deviation
0	84.523	16.460	80.868	16.459	95.971	28.262
−10	66.572	1.155	88.036	31.370	88.297	31.185
+10	66.939	0.529	65.989	0.372	66.430	0.964
−20	67.381	1.407	66.589	0.664	66.667	0.291
+20	66.751	0.718	65.954	0.547	66.065	0.478
−30	68.808	0.768	66.856	0.714	66.105	0.516
+30	67.221	0.437	66.962	1.367	67.027	1.899