Stress Analysis

It happens in the USA too. I know i have seen it.

You've seen oil cans used in load bearing columns? In the US?

No, i have seen weld rod laid down in a prep and just welded over(flux and all). All i am stating is the US has contractors that are willing to cut corners just to save a buck. It was my job to assure that the structure met code.

For the sake of argument. I could easily weld over a flux crusted prep weld and create a structurally sufficient weld. If it looks like there would be a issue, I could identify it and clean the flux and re weld as necessary. It might not be as pretty to skip around, but it would suffice and is a far cry from creating huge unstable pockets in the load bearing columns.

..that said.. I've worked for contractors willing to do anything to save a buck, and it's frustrating as hell!

I think texasron is talking about loose rods laid in the root area of a weld, and then just capped over, so that the resulting "weld" penetrated maybe even less than half the metal thickness. I've heard stories of Liberty ships done that way.

Yes! The Ultrasonic inspector came to me and was confused as he had never seen that condition. He stated it was like there was no weld there, no fusion no nothing. I had an outside contractor come in and air arc the cap and we saw just rods in the weld. This was on a stadium support leg. Contractor was fired and all welding done by that contractor was inspected.

This is not the first time. One job they called me in on there was I beams from outside the US that had just been butted up and a skin weld, then grind, paint for visual, was done. They had picked up the beam and it hit the structure while lifting into position and it just split into two parts and hit the ground.

Bottom line i have developed a mistrust of any supplier be it US or foreign.

I doubt the oil cans were on the original drawing. The fault may lie with the construction manager on-site to save some money on concrete but we'll have to wait for a full investigation to really be able to comment. Inspectors may have been bribed or they just didn't see the 'construction'. Lessons about ethics always seem to have to be learned the hard way. It's too bad the ones responsible weren't living in those flats. I'm glad I work for a company where anyone, and I mean ANYONE can call a stop if they see something they don't think is right. And the management will back them to the hilt.

First, I completely agree that engineers very likely would never design time bombs into their work.

I can see unethical builders doing this to save a buck.

I salute your company for empowering their employees to have a voice in making things better for everyone.

Good policy where anyone can call a stop. It's only common sense to have it. Engineers "usually" design for appropriate conditions-I cannot comment on all of us, but unless they are involved in the actual construction, it's anyone's guess as to how structures are actually built. Not uncommon to try to cut corners to save on cost and "developing" countries are especially prone to short cuts and other skullduggery.

This is clearly not an engineering change due to field conditions. Those are somewhat common, but procedures should be in place for any such possibility.

1. Why mentioning engineers if seemingly building practice is at fault? For me a builder is not same as an engineer
2. They arrested the developers - no say that it was an engineering fault
3. Even if you know how to do things right people might not do the right thing. So your assumption they learned stress analyses the wrong way is wrong.
4. The golden rule for the Golden Dragon building was that blue cans can save them buckets of concrete

My sympathy to the people of Taiwan too.

I mean, QA/QC engineers and consultant. Taiwan is an earthquake prone country, I bet design consideration should be around 7.5 at least. It's just a magnitude 6+ tremor, the design should stand through.

Just as a note, this will all change when a magnitude 8 one comes around. Just saying!

Strange. It looks as though they actually space the cans fairly evenly. Seems to have been a very deliberate effort. Perhaps a misguided attempt to duplicate roman concrete practices? In any case, it seems to me to be a fairly obvious culpable negligence case at the very least.

Very obviously, this is a contractor construction shortcut, nothing to do with stress analysis/engineering. From my experience, this was a case where the contractor attempted to stay on time/on budget, by creating a symmetrical void in the column. Kept pouring concrete even though was running out, or saved time by preventing the pouring of concrete.

Or......some organized crime syndicate decided not to bury some poor stiff in the column at the last minute.....

A major dam project in the UK had to be started afresh because under the original contractor half the cement was going out the back door.

It's the same the world over unfortunately.