Quote:
Originally Posted by Alistair
Have you seen how far aground ships can get? Even empty (which the Dali was not), that's a LOT of mass to slow down.
I guess the question is how much slower would the ship need to be to avoid a total collapse of the bridge?
And the Dali swerved pretty close to the bridge. Can we build crash structures close enough to take up the impact, but not also be pushed into the bridge.
No idea on the answers. But, it's definitely not as trivial as "just add some sand or a really big pylon".
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Its easy to design something for that. Its harder to ask (and answer) if the cost is worth it.
AASHTO has some guidance, but as I said in my other posts it comes down to risk in the decision making process - what is most likely to cause the most amount of damage, and how do you mitigate that to make it tolerable. Because again, we have thousands of structurally deficient bridges in the US that can fail without a big ol' boat running into them.
In my little corner of civil engineering we spend WEEKS figuring out what is the riskiest part of our structures, then decide if it's above or below a societal acceptance of risk, and then figure out if we need to address it.
The societal risk is somewhat dependent on all of us, the society - what is a threshold where people start to take notice for different types of failures/disaster, and what is the threshold where we demand action? Think of how we react when a plane crashes (or even just a panel flies off mid flight) vs. how many people die in car crashes per day in the US. It depends on a lot of things, and I'm all for making things as safe as we can. It typically takes a big disaster like this to nudge society (and congress/purse holders) to take action.
Sorry for the lack of commentary on insurance and tugboats
