Study on the dynamic response characteristics of lining structures in large-section tunnel blasting using JH-2 model...

Area of Science:

• Civil Engineering
• Geotechnical Engineering
• Tunneling and Underground Construction

Background:

• Tunnel lining structures, typically concrete, require protection from blasting vibrations during excavation.
• Ensuring tunnel stability and safety necessitates defining safe distances between blasting sources and lining structures.

Purpose of the Study:

• To investigate the safe distance for concrete lining from blasting sources to prevent vibration-induced damage.
• To analyze the influence of blasting parameters on tunnel lining integrity using numerical simulations.

Main Methods:

• Utilized the JH-2 constitutive model for simulating tunnel blasting.
• Obtained JH-2 model parameters for local surrounding rock through experimental testing.
• Performed numerical simulations and theoretical verification to determine safety distances.

Main Results:

• The JH-2 model accurately simulates stress wave propagation in various media.
• Closer material properties between lining and surrounding rock enhance interface safety.
• Peak Particle Velocity (PPV) in the lining increases with arch angle during ring blasting.

Conclusions:

• A minimum distance of 62m is recommended between concrete lining and blasting sources to mitigate vibration damage.
• Damage from concrete tensile failure is less significant than PPV-induced bonding interface damage.
• The study provides crucial data for safe tunnel blasting practices and lining design.