Prediction of ground vibration level induced by blasting at different rock units

Blasting is generally inevitable for hard rock excavation. Vibrations, induced from blasting affect adjacent and remote structures, as well as people in the neighborhood. This paper describes ground motions induced by blasting near underground and surface concrete structures during the construction of upper Gotvand dam. Effects of different rock formations, different detonators and explosives are analyzed. During underground and surface excavation, 498 ground motions, produces by 216 shots were measured with Vibraloc vibration monitors. Scaled distance and peak particle velocity data pairs were carefully recorded and analyzed statistically. This analysis allowed the document of empirical relationships between scale distance and peak particle velocity in different surface and underground regions. Finally, the particle and frequency values of further blast events were evaluated according to the USBM (RI 8507) to validate the relation and predict the influence level to the neighboring concrete structures.

► Velocity of 50 (mm/s) presents as a maximum particle velocity with no damage.
► In Aghajari formation, dynamic factors are change between 170–660 and 0.87–1.71.
► In Bakhtiary conglomerate, dynamic factors are change between 350–420 and 1.63–0.955.
► Vibration from underground blasting is at least 3times more than from surface blasting.