A study on surface damage characterization due to underground blasting

Peak particle velocity of ground vibration has been globally accepted as a criterion of blast damage to surface structures. Investigations were carried out to study the effect of underground blasting on surface structures in the vicinity of six collieries under varying geological conditions and different blast geometry. Characterization of ground movements due to underground blasting, frequency of vibration, duration of vibration, level of vibration and the structure's responses to ground vibrations are the important parameters in assessing any damage to surface structures caused by underground blasting. All together 39 blasts were performed and vibrations were monitored on surface at different locations. Structure's responses were also taken for some of the blasts. It was observed that the peak particle velocity decreased with the increase in the height of the structure. In the case of underground blasting, the frequency of blast vibration are much higher than the natural frequency of the structure and it is the reason for decrease of amplitude of vibration with the increase in height of the structure. The paper also discusses the different vibration standards followed globally.