3 ms·
For harder ground/solid rock it seems like you could slice off sections of the inner core material and not have to drill as much total material.
by cma 4y ago
For harder ground/solid rock it seems like you could slice off sections of the inner core material and not have to drill as much total material.
- imtringued 4y agoThis could make blasting the core easier because there is now room for the explosion to expand into (assuming portion of the tunnel liner is removable) and the shape of the tunnel can be optimized to be non circular.