Impact of orientation of blast initiation on ground vibrations

Abstract

The blast-induced ground vibrations can be significantly controlled by varying the location and orientation of point of interest from blast site. The blast waves generated due to individual holes get superimposed and resultant peak particle velocity (PPV) generates. With the orientation sequence of holes blasts on site, the superimposition angle of wave changes and hence results in significant variation in resultant PPV. The orientation with respect to the initiation of blasts resulting in lowest PPV needs to be identified for any site. By knowing the PPV contour of vibration waves in mine sites, it is possible to reduce the vibration on the structures by changing the initiation sequence. In this paper, experimental blasts were conducted at two different mine sites and the PPV values were recorded at different orientations from the blast site and its initiation sequence. The PPV contours were drawn to identify the orientation with least and highest PPV generation line. It was found that by merely changing the initiation sequence of blasts with respect to the sensitive structure or point of interest, the PPV values can be reduced significantly up to 76.9%. • The sensitive structure or point of interest should not be aligned along the direction of initiation of production blasts. • The PPV contouring method helps in identification of the orientation of least and highest PPV generation line. • PPV contour will help in better understanding of ground vibration generation in the particular geology of any mine site. • By merely changing the orientation of blast initiation with respect to the sensitive structure PPV may be reduced up to 76.9%.