An empirical model for determining of safety radius against air-blast in demolition operation of concrete structures
Subject Areas :
1 - عضو هیات علمی دانشگاه آزاد اسلامی واحد محلات، گروه مهندسی معدن
Keywords: Blasting demolition, Air-Blast, Concrete structure, Experimental model,
Abstract :
One of the new engineering techniques in the world is demolition by controlled blasting operation.The method contains some mining and civil engineering’s techniques. They are the controlledblasting, proper selection of type and amount of explosives, air-blast, ground vibrations and fly rockeffects and structure analysis, construction material properties, like mechanical strength of them. Thispaper has subjected to control of air-blast in concrete structures. Sometimes intensity of air-blast candue to fragment of windows and weak members of structures in faraway, if there are strong winds andinversion. It is clear that control of air-blast is very important; therefore four standards (USA, UK,Australia & Spain) for determining of allowable sound levels have collected in the paper.Authors made 22 concrete columns and three blast holes were drilled in each column. The holespacings have selected independently. It means that blast of a hole does not affect the on other holes.After each blasting, sound level in dB (A), distance and amount of explosives in each period haverecorded. Finally, the data were converted to logarithmical form and analyzed by multiple regressionsand was obtained an empirical model. Correlation coefficient of the model shows that the model’sresults are good agreement with empirical data. The model can evaluates safety radius against to airblast in demolition operation of concrete structures.