Monitoring and Prediction of the Vibration Intensity of Seismic Waves Induced in Underwater Rock by Underwater Drilling and Blasting

All underwater drilling and blasting operations generate seismic waves. However, due to a lack of suitable vibration sensing instruments, most studies on the propagation of seismic waves have been limited to shorelines near construction areas or wharfs, whereas comparatively few studies have been conducted on the larger seafloor itself. To address this gap, a seafloor vibration sensor system was developed and applied in this study that consists of an autonomous acquisition storage terminal, software platform, and hole-plugging device that was designed to record the blasting vibration intensities received through submarine rocks at a given measurement point. Additionally, dimensional analyses were used to derive a predictive equation for the strength of blast vibrations that considered the influence of the water depth. By combining reliable vibration data obtained using the sensor system in submarine rock and the developed predictive equation, it was determined that the water depth was an important factor influencing the measured vibration strength. The results using the newly derived equation were compared to those determined using the Sadowski equation, which is commonly used on land, and it was found that predictions using the derived equation were closer to the experimental values with an average error of less than 10%, representing a significant improvement. Based on these results,the developed sensor system and preliminary theoretical basis was deemed suitable for studying the propagation behavior of submarine seismic waves generated by underwater drilling and blasting operations.