| ▲ | bombcar 7 hours ago | |
Blasting through rock is expensive and only done if needed - I'd suspect that most projects now are cut and cover or tunnel boring machine - both of which can also be terribly expensive (see: Seattle). | ||
| ▲ | ianburrell 2 hours ago | parent | next [-] | |
Blasting through hard rock is easy. Finland has perfect rock and makes lots of tunnels with blasting. Soft rock needs support so TBM tunnels and shores up. | ||
| ▲ | rsynnott 6 hours ago | parent | prev [-] | |
Yeah, this one looks to be TBM for most of the underground sections. | ||