Quote:
Originally Posted by WarrenC12
Reasonable from a cost perspective. I'm sure they can be made to modern seismic standards.
Part of the reason the GMB proposal was so massive and expensive is because of how high it needed to go, and how much ground level work needed to be done due to where they were building.
It's also the reason a tunnel was built in 1959.
|
"Reasonable from a cost perspective."
Really? Because from what i've read any tunnel built to the same modern seismic & structural standards would be more expensive than a bridge, not less.
"I'm sure they can be made to modern seismic standards."
I'm not an expert in tunnelling, but remember that the area we're talking about is in fraser river silt/sand that will liquify in a major earthquake. When you build a bridge on friction piled foundations that can be addressed. How do you improve your substrate when tunnelling through weak soil?
"Part of the reason the GMB proposal was so massive and expensive is because of how high it needed to go, and how much ground level work needed to be done due to where they were building."
Remember the tunnel will also have to go deep to get under the river, and long trenched viaducts are required to do so.
I would be shocked if an equivalent tunnel is cheaper than a bridge. Tunneling is also FAR higher risk during construction.