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Abstract Criterion and damage zone induced by excavation blasting of underground power-house were studied by field test of blasting vibration and numerical simulation. The numerical simulation software FLAC3D was adopted with introducing damage variable D into elastoplastic constitutive model. The simplified triangular load was used as blasting load on the wall of blast hole. The blasting-induced damage zone was defined according to effective stress of rock. By revising the number of blast holes，the maximum quantity of explosive charge of single-stage priming was changed to study its relationship with blasting-induced damage zone. The results of numerical simulation show that the depth and the horizontal radius of damage zone increase with the increment of explosive charge of single-stage priming while the damage zone reduces with the increment of depth of blast hole. The maximum horizontal radius of damage zone is at the surface of the top of blast hole. According to the attenuation of particle velocity in the area near blasting source，the relationship between the maximum horizontal radius of damage zone and the critical vibration velocity for blasting-induced damage was obtained by numerical data fitting corresponding to the change in explosive charge of single-stage priming. The critical vibration velocity for blasting-induced damage was used as damage safety criterion of blasting. The study results can be used effectively in practice and have guiding significance for those similar blasting projects.
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Received: 12 May 2010
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2010, Vol. 29 
