Drilling and Blasting Techniques for Sinking a Well in a Water Reservoir-A Case Study for Underwater Controlled Blasting Methodology and Monitoring

摘要

Underwater drilling and blasting is conducted for deepening of sea channels for port berths, lake orreservoirs for water supply etc. so that rock dredging becomes easier. During this process there areseveral associated unwanted effects having potential to cause damage to surrounding structures and theenvironment, flora and fauna. Though all these ill effects can’t be completely eliminated but adoptingcontrolled blasting techniques can minimize these to tolerable levels. It is recognized that groundvibrations resulting from rock blasting below water near dam may endanger the safety of earthen dams.Therefore, controlled blasting technique was used to ensure the safety of dam and its efficacy wasestablished by monitoring of blast vibrations. The usage of small quantity of explosives confined in blastholes, non-electrical delay detonators and initiating each hole with a separate delay helped to minimizethe ground vibration effects on surrounding structures.