Abstract:

In order to study the influence of shorthole pressure relieving and vibration reduction method on the blasting vibration reduction effect of peripheral holes, the tunnel crosssection model before and after setting pressure reducing short holes are calculated and analyzed by ANSYSDYNA numerical simulation software; the blasting tests are carried out on tunnel crosssection before and after setting pressure reducing short holes; and then comparison is made on vibration velocity diagrams collected before and after setting of pressure reducing short holes. The results show that: 1) The blasting vibration velocity of peripheral holes after using shorthole pressure relieving and vibration reduction method is smaller than that before using shorthole pressure relieving and vibration reduction method. 2) The tunnel excavation contour line goes smooth and shaped; and the overbreak and underbreak times have been reduced by using shorthole pressure relieving and vibration reduction method.

Key words: Metro tunnel, blasting of peripheral holes, shorthole pressure relieving and vibration reduction method, numerical simulation, test, vibration velocity