Control Blasting Technique of Cutting Excavation in a Roadbed
Chi En-an · Blasting · 2012
In order to strictly control the harm of blasting vibration and flying rocks,specific to the complex surrounding environment of Donlian No.2 road in cutting excavation,a blasting plan combined short-hole blasting with pre-splitting blasting was adopted.The main blast holes which were decoupling charge were detonated by hole-by-hole blasting;the presplit holes was connected with detonating cord;each 5 holes were connected with 25 ms detonators to realize small microsecond delay time relay connection.The main blast holes and pre-splitting holes both used high precision digital detonators to realize accurate time delay,avoiding the superposition of blastin vibration which caused by wrong delay time related to time delay error of normal nonel detonator.The blast holes were covered by 4-layer rubber network coverage,with which the effect of flying rock was prevented effectively.The blasting program achieved the desired results,it may provide a reference for similar projects.