Response of Surface Structures to Rock Blasting

Investigations were carried out to study the response of surface structures to rock blasting. The experiments were conducted in four opencast and one underground coal mine. The structures in the vicinity of the mining area were single and multistorey residential buildings. The amplitudes of vibration were monitored simultaneously on the ground and on various floors of the structures. It was observed that the ground peak particle velocity amplified more than six times on the top floor of one of the structures. However, vibration in similar structures due to blasting in underground coal mines decreased with the increase in the height of the structures. The frequency of blast vibration from opencast blasting was in the range of natural frequency of the structures whereas from underground blasting, it was much higher than the natural frequency of the structures. It indicates that the dominant frequency of blast vibration plays an important role in the amplification of vibration in the structures. This paper deals with the effect of the blast vibrations on structures/buildings in different Indian geo-mining conditions.