Recently, an under-construction Silkyara-Barkot tunnel in Uttarakhand collapsed trapping 40 workers inside.
Silkyara-Barkot Tunnel |
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Excavation Methods |
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Drill and Blast method (DBM) |
Tunnel boring machine method |
Description |
Involves drilling holes into the rock face and blasting it with explosives to break it into fragments |
Involves a shielded machine that bores through the rock with a rotating cutter head |
Tunnel length |
Adopted for shorter tunnel range up to 3km |
Adopted for long tunnel up to 25 km |
Suitability |
For hard rocks and high mountain tunnel |
For soft rock and low mountain tunnel |
Environmental impact |
Causes more vibrations, noise, dust, and gas emissions |
Faster, safer and environment friendly than DBM |
Cost |
Cost effective for shorter tunnels and smaller projects |
Requires high initial investment and more technical expertise |
Example |
Himalayan regions including Jammu & Kashmir and Uttarakhand |
Underground tunnels for the Delhi metro |
Related links - Sikkim flash floods, Joshimath crisis
References