Grandfather Mountain. The Linn Cove Viaduct is that tiny, tiny line on the bottom left corner of the photo.
Crossing under the viaduct into Grandfather's boulder field.
One of the larger boulders, with the viaduct for scale.
Looking back at Grandfather from the bike.
The Viaduct is an amazing work of engineering, and yet there's remarkably little information about how it was constructed online, from what I can see. I can't tell how they supported the cantilever of up to 90' until reaching the next pier from any information I've seen online. Neat bridge.
ReplyDeleteIt was the last thing finished, and that in the ‘80’s. If you can’t find what you want online, you might still find one of the men who built it.
ReplyDeleteSomething similar was done out west in the same time frame. I think it was I70 through Colorado's Glenwood Canyon. I remember watching a documentary on it so you might want to look that up for an idea of what was done.
ReplyDeleteI have a young friend hiking the AT this year who is likely just pulling even with that now. I hear the ridge-running in NC/TN is nice, but VA is a long slog.
ReplyDeleteI've always been a sectional hiker, never a through hiker, so I can't speak to Virginia as a whole. But the AT does run through the Shenandoah National Park, and the bit right at the top of Virginia going into WV (where Harper's Ferry is), both of those sections are quite nice.
ReplyDeleteThanks Christopher- indeed that looks to have been a similar or even identical method of construction. I'll look into it.
ReplyDeleteAnd a few minutes poking around the internet takes me to the website of the contractor that built the Glenwood canyon project- and a picture that answers most of my questions- a long cantilevered slipform gantry that works much like a self erecting construction crane, but all horizontally. Neat. I'd love to see more roadways constructed in this fashion, but it must be significantly more expensive.
ReplyDeleteSorry, but I'm fascinated- Wikipedia has a pretty good overview of the process, surprisingly enough. The answer to the question that was foremost in my mind was what hold the latest segment to the cantilevered assembly until the span is completed, and the answer is that the reinforcing steel is used to connect the new segment to the previous, and each in turn- as each segment is made to hold steel that attaches to the previous section as well as steel that will be used to attach the next section beyond it.
ReplyDeleteWell, that's enough civil engineering lessons for the day.