ABSTRACT
The existing old ports have to be renovated to accommodate vessels with higher drafts, and if necessary, the aged berths have to be dismantled, and new berths are constructed. In the case discussed, the old berth has turned unserviceable with age, and there is a lack of minimum draft available to shelter new vessels. It is decided to make berths suitable for boarding vessels with a draft up to 14 m. The old berths were made of 22 vertical caissons, constructed partially using rubble masonry and partially using RCC masonry. It is decided that the old berths have to be demolished and the draft has to be brought to − 16.1 m. The vibrations and peak particle velocities were measured at the location were found to be within the desirable limits set by Indian standards. A graph is plotted between peak particle velocity and scaled distance, and a correlation is drawn between ground vibration, distance and explosive charge. The desirable maximum explosive charge per delay for blasting with varying radial distance keeping the existing structures in vicinity safe and sound can be obtained using the derived correlation.
