Stability analysis and blasting vibration control technology of shallow tunnel under unsymmetrical pressure

摘要

Basing on Huolangyu tunnel,the authors use the finite software MADIS-GTS to analyze stress field,displacement field,and plastic zone distribution of the surrounding rock under tunnel entrance excavation.They also study stress distribution rules of unsymmetrical pressure section with backfilled soil.After a comparative analysis of the monitoring data,the authors define the key controlled zones of rock unsymmetrical deformation and stress concentration,they advise some effective measures to avoid partial tunnel destruction.Through monitoring the blasting vibration on key controlled zones,the authors analyze the correlation between blasting vibration effect and blasting condition,they put forward the blasting vibration control technology,such as stress improvement of surrounding rock,the multi-stage small wedge cutting holes,reasonable holes design,information-based construction,optimized blasting parameter.The methods will ensure the excavation safety in shallow buried tunnel under unsymmetrical pressure.