HARD ROCK EXCAVATION FOR FOUNDATIONS: MYTHS AND BEST PRACTICES IN ROCK BLASTING

Srikant Vairagare, G. Shivaleelanand

Abstract: Each high-rise building requires equally deep foundations. Part of India that is expanding fast such as South and West India are sitting on one of the hardest rock known to the mankind such as Granites and Basalts. Thus, leaving no other option but to resort to Rock Blasting for excavation of foundations. Green building guidelines suggest least disturbance to the expense of natural ground for cellars. It indirectly suggests buildings to limit their basements to building outer line only not going beyond building line into setback areas, which necessitates going for deeper excavations. Provision of mechanical parking in basements necessitates more heights in basements, hence deeper excavations. Blasting creates nuisances such as Fly Rock (Flying projectiles), Noise, Heat, Vibrations and Noxious Fumes. Blasting damage is often falsely compared to damage resulting from earth quake. Mishandling of situation had resulted in abandoning construction of a few floors and enormous delay in project execution. There are instances of few projects being stopped altogether. Controlled blasting limits the spread of dust, sound and limits the flying fragments making the construction process green. Blasting is the cheapest and the fastest method of Rock Breakage. It’s the safest too, as can be seen its use in crowded cities such as Hong Kong for the construction of Hong Kong Metro, where up to and 1100 Cubic Meters of Hard Rock was excavated per day and the city of New York for reconstruction near World Trade Centre, where slightest error would not only stop the project but would attract penalties to the tune of millions of USD. This paper discusses the ways to dispel the fears about blasting and use it effectively in Indian Civil Engineering practices

Keywords: BEST PRACTICES IN ROCK

DOI: https://doi.org/10.15623/ijret.2016.0532041