Bridge collapse in Miami, 6 dead

[therealdope]

I think the architect also called for a specific type of joint and the builder used a different kind without the architect knowing.

Obligatory pic that I took last year from the citi bldg 50 floors up looking north.

 

[ralphc1]

Ummmm --- no.

THe citicorp building was never designed to withstand hurricanes because it was never an engineering requirement or design spec for buildings in that region. The chief architect was watching the news and heard that a hurricane might come up to NYC and yelled "WTF? Hurricanes can hit NYC? That building isn't designed for hurricanes". That set off the secret nightly project to try and fix it. They never finished and were lucky the wind swept it out to LI.

The strengthing project was started long before the hurricane. Diane Hartley was doing her thesis on the Citicorp building and got the design specifications from Joel Weinstein. She noticed that there were no stress figures for quartering winds and asked Weinstein about them. That started the whole process. They had developed evacuation plans with the city as they started strengthening the connections in the structure months prior to the hurricane.

http://www.onlineethics.org/DianeHartley.aspx

 

[ralphc1]

The strengthing project was started long before the hurricane. Diane Hartley was doing her thesis on the Citicorp building and got the design specifications from Joel Weinstein. She noticed that there were no stress figures for quartering winds and asked Weinstein about them. That started the whole process. They had developed evacuation plans with the city as they started strengthening the connections in the structure months prior to the hurricane.

http://www.onlineethics.org/DianeHartley.aspx

Hurricanes are nothing new to New York.

 

[therealdope]

Hurricanes are nothing new to New York.

They weren't planned for or a design spec.

 

[therealdope]

Hurricanes are nothing new to New York.

They weren't planned for or a design spec. I guess the quartering winds are something that only occur once every 55 yrs. So since that would put the date back to 1915 from the design date which would be sketchy in terms of how much wind data they had for historical reference.

As usual, engineering fuck ups come from a confluence of factors.

For occupant comfort, the building has a tuned mass damper, which also negates much of the wind load. The damper is electrically activated, so if power failed, say during a hurricane, the damper might not turn on[7] and a much lower-speed wind would suffice; wind of this speed occurs on average once in 16 years. LeMessurier also discovered that his firm had used New York City's truss safety factor of 1:1 instead of the column safety factor of 1:2. These factors, combined, put the building in critical danger. The problems were discovered in June, the beginning of hurricane season, and had to be corrected quickly.[8]

 

[IIIIIIII]

How are bridges and other public works not inspected by many, many professionals so that someone catches mistakes?