Evaluation of blast induced ground vibration for minimizing negative effects on surrounding structures

The present paper mainly deals with the prediction of blast-induced ground vibration level in Bakhtiary formation at intake of waterway system in Gotvand dam, Iran. For this research the ground vibration components were recorded carefully by means of 3 sets of vibration monitors for 32 blast events during the bench blasting in front of tunnels. Then, the data pairs of scaled distance and particle velocity were analyzed by using the USBM equation. At the end of statistical evaluations, a relationship between peak particle velocity and scaled distance for this site was established with good correlation. Again, other data measurements during tunnel excavation near concrete structures were used to validate the predicted PPV and optimize the blasting patterns to omit the effects of resonance and vibration in USBM (RI-8507) standard. Based on the vibration tests done in Bakhtiary conglomerate, constant dynamic factors of the rock mass related to vibration velocity are 159.07 and 1.077.

► Velocity of 50 (mm/s) presents as a maximum particle velocity with no damage.
► In Bakhtiary conglomerate, dynamic factors are 160 and 1.078.
► Vibration from underground blasting is at least 3-times more than surface blasts.
► Frequencies of blasts with different detonators in conglomerate are higher than 20 Hz.
► Potential of damage risk and self structural frequencies were analyzed.