Quote:
Originally Posted by bomberjet
10.3 million to install the steel arch and road detour? Based on the imagery in the AIL webpage, there seems to be lots of elevations change already built into that area which makes everything a lot easier.
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That's fair. It begs the question if TCH underpasses make more sense too. Even on flat ground. Of course it's very water table dependent.
But by digging instead of building up, you're working with virgin ground, virtually eliminating compaction and hauling in fill. Which is faster and cheaper. As for the actual bridge/tunnel portion, the process seems quite simple and fast: Dig out TCH lanes, pile-it and/or pour footings, assemble the arch, then fill it back in. This is that process the
French were doing in 3-5 days total.
There's a safety aspect to underpasses too. Any interchange type creates a blind spot to approaching traffic after the bridge. Big collision risk. But with underpasses, the traffic is going up an incline, adding to their braking ability if someone cuts out from the approach. As opposed to an overpass, where they're going downhill if they need to step on the brakes, greatly reducing stopping distance. And this is only magnified on ice (which we get). Hmmm.