So you expect this to be above ground? I'd expect that it would be bored since (in states where mineral rights aren't held by the land owner) it's cheaper than above ground right of way. At boring depths (greater than 60ft or 20m) temperature change is less than 0.1c and thermal expansion ~10ppm. Serpentines 100km in diameter could easily be used with radial deflections of only 10cm. The g-load at 1080km/hr=300m/s with 100km radius is less than 1/10th of a g.
You should be designing with much larger margins than 10cm and 0.1g for anything carrying humans. Shock absorbers in the pod to deal with short range ripples (100um/100m) would be a much bigger issue. That's what I mean by accidental serpentine that makes the problem completely secondary.
If you've got calculations, then show them... otherwise please find a different bike shed.
The original Hyperloop proposal was elevated, so ... yes.
As far as I am aware of, there are three different things: 1) Hyperloop as originally planned, for above-ground long-distance travel 2) tunnels under dense cities, for existing cars carried on, perhaps, electric sledges, 3) a "verbal agreement" mentioned by Musk about an Easy Coast tunnel hyperloop which no government official has confirmed, and with no concrete plans that anyone can say anything about. Will it be bored? Will it be 20+m down? What route will it take?
So, what is it that you expect will be bored? A, ~5 meter wide high-speed tunnel from L.A. to San Francisco across multiple active faults? (Or rather, two such tunnels as you want traffic in both directions.)
Gas pipelines are only, what, 100-150 cm across? They are built to either move with the ground or force the earth move around them. Any such movement is going to have rather less than a 100km radius. How do we scale up that knowledge to a Hyperloop tunnel? Will we also built the Hyperloop tunnel out of steel?
This isn't bike shedding. We know it's possible to build a Hyperloop by throwing enough money at the problem. For example, we can solve above-ground thermal issues by simply enclosing the hyperloop in a flexible insulated chamber and running heaters or chillers to keep the temperature inside constant. But that would be prohibitively expensive.
Since there isn't a concrete proposal for what some high-speed long-distance tunnel is supposed to be, there's nothing to bike shed. Tom Swiftian dreams of the World of Tomorrow must first demonstrate they can overcome the hard realities the the World of Yesterday discovered.
Why didn't Tom Swift dream of upgraded sewage treatment systems?
Yes, I always thought those pictures of above ground hyper-loop looked silly. It's not like you're going to be in a transparent tube (first mass use of VR please B^). But all of these comments are off the original expansive topic, and in fact much more relevant. Thermal expansion simply isn't a problem that needs to get solved, because holding sub-mm tolerances over a km is unrealistic, and if cost was an issue, you'd put the dann thing in the ground.
Don't confuse me with someone who finds hyper-loop realistic... but don't tell me it can't be done because it needs 5 doors and to be painted a particular color of red. I don't particularly care what some ex-paypal guy who runs a car company says about it either. Engineering matters.
You should be designing with much larger margins than 10cm and 0.1g for anything carrying humans. Shock absorbers in the pod to deal with short range ripples (100um/100m) would be a much bigger issue. That's what I mean by accidental serpentine that makes the problem completely secondary.
If you've got calculations, then show them... otherwise please find a different bike shed.