Assessment of Seismic Activity and Ground Vibration Near Quarry Blasting Sites in Edo State

Quarry blasting activities generate ground vibrations that can cause structural damage to nearby buildings, annoyance to residents, and destabilization of slopes if not properly controlled. This study assesses seismic activity and ground vibration peak particle velocity at three aggregate quarry sites in Edo State, South South Nigeria, where blasting operations occur regularly. Seismograph instruments were deployed at distances of 50 m, 100 m, 200 m, and 500 m from each blast center, and vibration recordings were made during fourteen blasting events over a two-month field campaign. Peak particle velocity, peak vector sum, and dominant frequency were extracted from seismograph records for the vertical, transverse, and longitudinal vibration components. Results are compared against the British Standard BS 7385 and the American Institute of Mining Metallurgical and Petroleum Engineers vibration limits for residential structures. Peak particle velocities at 50 m ranged from 12 mm/s to 68 mm/s, with six of fourteen blasting events exceeding the 12.7 mm/s conservative residential limit at 100 m. The study applies Scaled Distance analysis to develop site-specific attenuation relationships for predicting ground vibration as a function of explosive charge weight and distance. Recommendations include reduction of maximum instantaneous charge, use of delay detonation timing to reduce constructive wave interference, and mandatory pre-blast and post-blast structural condition surveys of adjacent buildings. Keywords: ground vibration, quarry blasting, peak particle velocity, Edo State, seismic assessment