Key technologies of precision demolition blasting of ultra-long urban viaduct in complicated surroundings

The key technologies of precision blasting were put forward based on the characteristics of urban viaduct blasting demolition in complicated surroundings.Initial bending instability mechanics model of reinforcing steel bar frame of blasting fragmented pier and sequenced collapsed dynamic model were established for quantitative blasting design.Technologies of water pressure blasting were applied in multi-cell box girder fragmentation.The detonating network of non-electric duplication crossover was adopted for the safety and reliability of ultra-long delay.The rationality of blasting scheme and parameters were validated by physical model test.Harmful effects were forecasted and controlled by integrated protective technologies.Specialization,cooperation,precision,execution(SCPE) project management method was put forward for precision management.The key technologies of precision demolition blasting can provide reference for similar projects.