ABSTRACT
The research investigates the blasting techniques used to excavate a large diversion tunnel at the Pakal Dul Dam site in India. This project is part of India’s strategic initiative to enhance its hydroelectric capacity. The diversion tunnel, featuring a horse-shoe shape, is 12.2 m in span and 847.7 m of a total of 859.7 m is excavated in hard rock. The study focuses on the drilling and blasting method, employing key techniques such as V-cut patterns and horizontal stab holes to optimize the project for cost-effectiveness and adaptability to various geological conditions. The research outlines the blast design parameters, including the use of emulsion explosives and non-electric detonators, to achieve optimal excavation results while minimizing overbreak and vibrations. The findings demonstrate the effectiveness of V-cut patterns in achieving an average advance per round of 80.7%, despite challenges such as quartz veins, shear seam, hard rock masses, and four to five joint sets.
