www.sefindia.org

STRUCTURAL ENGINEERING FORUM OF INDIA [SEFI]

 Forum SubscriptionsSubscriptions DigestDigest Preferences   FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups  RegisterRegister FAQSecurity Tips FAQDonate
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log in to websiteLog in to websiteLog in to websiteLog in to forum 
Warning: Make sure you scan the downloaded attachment with updated antivirus tools  before opening them. They may contain viruses.
Use online scanners
here and here to upload downloaded attachment to check for safety.

William LeMessurier & The Citigroup Center, New York

 
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> Engineering Marvels
View previous topic :: View next topic  
Author Message
Dr. N. Subramanian
General Sponsor
General Sponsor


Joined: 21 Feb 2008
Posts: 5430
Location: Gaithersburg, MD, U.S.A.

PostPosted: Tue Dec 28, 2010 4:28 am    Post subject: William LeMessurier & The Citigroup Center, New York Reply with quote

William LeMessurier & The  Citigroup Center, New York

William James LeMessurier Jr. was born on June 12, 1926, in Pontiac, Mich. He was the youngest of four children of William James LeMessurier Sr., who owned a dry-cleaning business, and the former Bertha Sherman, a homemaker.

Mr. LeMessurier majored in mathematics at Harvard and earned a B.A. in 1947. He studied architecture at Harvard’s Graduate School of Design and received a master’s from M.I.T. in building engineering and construction in 1953.

He was the founder and chairman of LeMessurier Consultants. He was awarded the AIA Allied Professions Medal in 1968, elected to the National Academy of Engineering in 1978, elected an honorary member of the American Institute of Architects in 1988, and elected an honorary member of the American Society of Civil Engineers (ASCE) in 1989.

While responsible for the structural engineering on a large number of prominent buildings, including Boston City Hall, the Federal Reserve Bank of Boston, the Singapore Treasury Building and Dallas Main Center.

Besides his daughter Irene, of New Ipswich, N.H., Mr. LeMessurier is survived by his wife of 54 years, the former Dorothy Judd; another daughter, Claire, of Westminster West, Vt.; a son, Peter, of Boulder, Colo.; and seven grandchildren.

He once told a class at Harvard: “You have a social obligation. In return for getting a license and being regarded with respect, you’re supposed to be self-sacrificing and look beyond the interests of yourself and your client to society as a whole. And the most wonderful part of my story is that when I did it, nothing bad happened.
The  Citigroup Center, New York

This 900-foot aluminum and glass skyscraper is the fourth tallest building in New York and the tenth tallest in the world. Double-decker elevator cars reduce the area devoted to the vertical circulation core, leaving more space available for offices. With so few interior columns, ample room is available for numerous amenities, such as a six-story retail wing and a sunken plaza that leads directly to the subway. Plans for creating residential space on the upper floors were abandoned due to zoning restrictions.

Regardless, as a mixed-use complex, this building has more in common with Art Deco skyscrapers than with the purely corporate structures of the International Style. The obliquely slanting roof--originally designed to hold solar panels--embodies another break with the practices of corporate high modernism. Standing out among the flat-roofed prisms of midtown, Citicorp's pitched roof has become a symbol of the corporation, a marker of corporate identity in an emerging area. The building's bold presence helped to revitalize the commercial area located to the east of Park Avenue.

Vital Statistics:
Location: New York, New York, USA
Completion Date: 1977
Cost: $175 million
Height: 915 feet
Stories: 59
Materials: Steel
Facing Materials: Aluminum, reflective glass
Engineer(s): William LeMessurier and Associates

From the very beginning, the Citicorp Center (today, the Citigroup Center) in New York City was an engineering challenge. When planning for the skyscraper began in the early 1970s, the northwest corner of the proposed building site was occupied by St. Peter's Lutheran Church. The church allowed Citicorp to build the skyscraper under one condition: a new church would have to be built on the same corner, with no connection to the Citicorp building and no columns passing through it.



How did the engineers do it?
Structural engineer (late) William LeMessurier set the 59-story tower on four massive 114 foot (35 m) high columns, positioned at the center of each side, rather than at the corners. This design allowed the northwest corner of the building to cantilever 72 feet (22 m) over the new church. To accomplish these goals LeMessurier designed a system of stacked load bearing braces, in the form of inverted chevrons. Each chevron would redirect the massive loads to their center, then downward into the ground through the uniquely-positioned columns.

Engineering Crisis in 1978

In 1978, prompted by a question from a student, LeMessurier discovered a potentially fatal flaw in the building's construction: the skyscraper's bolted joints were too weak to withstand 70-mile-per-hour (113 km/h) wind gusts at specific angles. if hurricane-speed winds hit the building at a 45-degree angle there was the potential for catastrophic failure due to bolt failure. The wind speeds needed to topple the models of Citigroup Center in a wind-tunnel test were predicted to occur in New York City every 55 years. If the building's "tuned mass damper" went offline, the necessary wind speeds were predicted to occur every 16 years.

With hurricane season fast approaching, LeMessurier took no chances. He convinced Citicorp officers to hire a crew of welders to repair the fragile building. For the next three months, a construction crew welded two-inch-thick steel plates over each of the skyscraper's 200 bolted joints, permanently correcting the problem.

Despite the fact that nothing happened as a result of the engineering gaffe, the crisis was kept hidden from the public for almost 20 years. It was publicized in a lengthy article in The New Yorker in 1995. LeMessurier was criticized for insufficient oversight leading to bolted rather than welded joints, for misleading the public about the extent of the danger during the reinforcement process, and for keeping the engineering insights from his peers for two decades. However, his act of alerting Citicorp to the problem inherent in his own design is now used as an example of ethical behavior in several engineering textbooks. After the modifications of the bolted members were completed, the building is now generally considered to be one of the most structurally sound skyscrapers in the world.

Notable features
To help stabilize the building, a tuned mass damper was placed in the mechanical space at its top. This substantial piece of stabilizing equipment weighs 400 tons (350 metric tons) and has a volume of 255 cubic feet (7 m³). The damper is designed to counteract swaying motions due to the effect of wind on the building and reduces the building's movement due to wind by as much as 50%. Citigroup Center was the first skyscraper in the United States to feature a tuned mass damper.

The building features double-deck elevators, which are separated to serve only odd or even floors.

The intersection at which the building is located was immortalized in a song by punk rock band The Ramones. The song, written by Dee Dee Ramone and released in February 1976, refers to a famous spot for male prostitution, where it is speculated that Ramone himself had worked as a "hustler".
The corporate headquarters of Citigroup are not located in this building, but across the street in 399 Park Avenue.

Fast Facts:

    * The Citicorp crisis of 1978 was hidden from the public for almost 20 years.
    * The 30-page document outlining the structural mistakes in the Citicorp building was called "Project SERENE." The acronym stands for "Special Engineering Review of Events Nobody Envisioned."
    * Six weeks into Citicorp's repair, a major storm, Hurricane Ella, was off Cape Hatteras and heading for New York. With only half the repairs finished, New York City was hours away from emergency evacuation. Luckily, Ella turned eastward and veered out to sea.
    * Citicorp Center was the first skyscraper in the United States to contain a tuned mass damper, a pendulum-like device that reduces the sway in tall buildings caused by the wind.

References:
1. http://www.pbs.org/wgbh/buildingbig/wonder/structure/citicorp.html
2. Joe Morgenstern (1995), "The Fifty-Nine-Story Crisis", The New Yorker, May 29, 1995. Pages 45–53.
3. http://www.nyc-architecture.com/UES/UES001.htm
4. http://temp.onlineethics.org/moral/lemessurier/index.html
5. http://en.wikipedia.org/wiki/Citigroup_Center
6. http://en.wikipedia.org/wiki/William_LeMessurier
7. http://www.lemessurier.com/
8. http://www.duke.edu/~hpgavin/ce131/citicorp1.htm


Last edited by Dr. N. Subramanian on Tue Apr 03, 2012 5:22 pm; edited 1 time in total
Back to top
View user's profile Send private message
abhio
...
...


Joined: 08 Mar 2010
Posts: 529

PostPosted: Tue Dec 28, 2010 6:17 am    Post subject: Reply with quote

Dear Dr N S Sir,

I would say that more than the strength of the building, it was the strength of
Le Messurier's character that was tested in the crisis, and he stood up to the test in a way that any man would be proud to emulate. Rather than lying low and risking the lives of the people in the building,
Le Messurier made his mistake public and stood up to the results.

We can only pray that if - heaven forbid - we should be in a similar position, we should also have the strength to come clean with our heads held high.

Regards,

_________________
A S Oundhakar,
Principal Engineer,
Invictus Consultancy Services,
Mumbai
Back to top
View user's profile Send private message
naveen
SEFI Member
SEFI Member


Joined: 03 May 2008
Posts: 12
Location: Bangalore

PostPosted: Sat Jan 08, 2011 4:18 am    Post subject: Reply with quote

Dear Dr N S Sir and all SEFI users,

I am sharing an article "THE FIFTY-NINE-STORY CRISIS" with this post. It gives a detailed account of the crisis surrounding the Citicorp building then, the drama that unfolded when LeMessurier came to know about the structural issues and about how he faced the situation.
I think it's a must read for all the structural engineers.

Please go the link below for the document
http://www.4shared.com/document/HATxzRrV/citicorp.html

Regards,
Naveen.
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topicReply to topic Thank Post    www.sefindia.org Forum Index -> Engineering Marvels All times are GMT
Page 1 of 1

 

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum


© 2003, 2008 SEFINDIA, Indian Domain Registration
Publishing or acceptance of an advertisement is neither a guarantee nor endorsement of the advertiser's product or service. advertisement policy