Fig 1.
Block diagram of the method of delay time for tunnel blasting.
Fig 2.
Single-hole blasting casting body.
Fig 3.
Front view of the wedge-shaped cutting blasting holes.
Fig 4.
Layout of different blast holes of the A-A tunnel section.
Fig 5.
Layout of the blast-holes and the initiation times of non-electric detonators.
Fig 6.
Spacing in drilling and lengths of the holes.
Table 1.
Blasting parameters using non-electrical detonators.
Fig 7.
Monitoring point layout of the transverse ground vibration of tunnel.
Fig 8.
Velocity of tunnel blasting using non-electric detonators (Part I blasting).
Fig 9.
Frequency domain of tunnel blasting using non-electric detonators (Part I blasting).
Fig 10.
Vibration velocity curve of the blasting signal using non-electric detonators for Part I blasting.
Fig 11.
Tunnel holes layout from top view (Unit: m).
Table 2.
Density experiment results of sandstone rock.
Fig 12.
Rock acoustic measurement test and testing instrument.
Table 3.
Velocity of longitudinal wave of the test rock.
Table 4.
Millisecond delay times for cut holes.
Fig 13.
Different delay times for cut holes.
Fig 14.
Vibration velocity curves of blasting signals for cut holes for a delay time of 2 ms.
Fig 15.
Vibration velocity curves of blasting signals for cut holes for a delay time of 3 ms.
Fig 16.
Vibration velocity curves of blasting signals for cut holes for a delay time of 4 ms.
Fig 17.
Vibration velocity curves of blasting signals for cut holes for a delay time of 5 ms.
Table 5.
Test results of different delay times for cut holes.
Table 6.
Millisecond delay times of different blast holes.
Fig 18.
Layout and delay times of the tunnel holes (Unit: ms).
Fig 19.
Typical blasting seismic wave using digital electrical detonators.
Fig 20.
Frequency of tunnel blasting using digital electrical detonators.
Table 7.
Blasting parameters using digital detonators.