Vibration Reduction and Explosion Control Investigation for an Ultra-Shallow Buried Tunnel under Crossing Buildings...

Area of Science:

• Geotechnical Engineering
• Civil Engineering
• Mining Engineering

Background:

• Increasing use of underground space necessitates tunnels beneath buildings.
• Drilling and blasting for ultra-shallow tunnels pose vibration risks to structures.
• Controlling blasting vibration is crucial for tunnel construction safety.

Purpose of the Study:

• To investigate and reduce blasting vibration impacts on ground buildings during ultra-shallow tunnel excavation.
• To propose and validate optimized blasting schemes for vibration control.
• To analyze the influence of various factors on surface vibration.

Main Methods:

• Field tests were conducted on an ultra-shallow tunnel section.
• Proposed and tested various footage schemes (0.6m, 0.8m) and millisecond delay detonation techniques.
• Hilbert-Huang Transform (HHT) analysis was used to compare surface vibration velocities and instantaneous energy.

Main Results:

• A 0.6m footage design scheme was verified through field tests.
• Millisecond delay detonation schemes were proposed for vibration reduction.
• Free surface, dynamite charge mass, and tunnel burial depth were identified as significant factors affecting surface vibration.

Conclusions:

• Optimized blasting schemes, including footage and millisecond delay detonation, can effectively reduce vibration.
• Understanding the influence of free surface, charge mass, and burial depth is key to vibration control.
• The findings provide valuable insights for managing blasting vibrations in ultra-shallow tunnel projects.