I agree it is cheaper to leave the forms in place than it would be to remove them. But your comment of “Leave them there if you can, but you don’t need to” tends to make Bernie’s point and also negates your (unnecessary as far as I am concerned) comment to Bernie of “Bernie, why don’t you take out some of those unnecessary beams in your home and sell them?”

If removing the forms is an option, then that means the support columns have been designed with a sufficient safety margin to (hopefully) withstand the “Big One” with minimal damage without the forms. Otherwise, removing them would not be an option. In that case, why spend the extra money to “overdesign” the forms?

If the cost of upgrading from 36ksi to 50ksi is $50,000, then the total extra upgrade cost for the 154 columns mentioned in the article is $7.7 million. Wouldn’t it be better to take that $7.7 million and use it on other parts of Link? That just gives more ammunition to the “Sound Transit just wastes taxpayer money” crowd.

Here’s what I think actually happened:

1) We need steel forms because this is underground.
2) The cost of removing them all is something like $75,000.
3) The cost of upgrading from 36ksi to 50ksi is $50,000, and would add one more layer of structural integrity in The Big One.
4) What do state and federal design manuals suggest? Leave them there if you can, but you don’t need to.
5) We can, and it’s cheaper to make them better than to remove them.
6) Decision made.

This is the most ridiculous non-issue I’ve seen in a while. Frankly, it was a good decision.

Like I’ve said, wait until ad revenue drops in advance of holiday ad buys. This is going to be epic.

Personally, given the small price delta, I’d rather have ST use the higher strength stuff, but it’s really not that big a deal either way.

And I don’t think people are that concerned about ST — if they thought ST was doing a bad job they wouldn’t have voted to fund ST2. People are generally pleased with ST, and not just those of us on STB.

Now if you want to see some really hardover commentators, go read the comments on the Times article.

But the contractor should have asked for a deviation – covering up a mistake is always worse than making it in the first place.

One such structure designed using this approach was the I-35W bridge that collapsed in Minneapolis. In retrospect, not only were the gusset plates undersized, but the structure was not fault tolerant.

The first thing a good engineer learns coming out of school is that it is impossible to fully predict the operating environment that your design will experience over its lifetime. Loads change, critical maintenance gets deferred, new chemicals and paints get applied, people do stupid things in unimaginably stupid ways, etc.

For this reason structures always get overbuilt. ST is right to do it; in fact, they are obligated by real world experience to do it.

That mid-60’s approach to reduced margin design is now out of favor. We’ve learned that even with powerful computers and smart people we can still make mistakes.

(Note: There is a parallel with our current economic meltdown. Apparently we thought we were so smart with all our new financial tools that we could accurately predict and model risk. Therefore we could increase our leverage without risk and………collapse.)

More is not better in civil engineering. You design to a safety factor. It’s a common misconception that making something stronger is better engineering. Seismic design assumes flexibility in a structure. If you make part of a structure less flexible you can compromise the entire design. If a structural column calls for 20 pieces of rebar an inspector will reject it for 24 pieces the same way he would if there was only 16.