While this column all too frequently focuses on unethical behavior, it is import
ID: 2747263 • Letter: W
Question
While this column all too frequently focuses on unethical behavior, it is important to recognize that most ASCE members and engineers uphold high standards of professional conduct even in challenging situations. In light of the recent passing of William J. LeMessurier, p.e., Hon.m.ASCE, the 1993 recipient of ASCE's George Winter Award, this article commemorates his praiseworthy and exemplary behavior upon discovering a serious flaw in the design for New York City's Citicorp Center.
Situation: The 59-story Citicorp Center, one of New York City's most distinctive skyscrapers, was the brainchild of the structural engineer William J. LeMessurier and the architect Hugh Stubbins, Jr. A deal struck by Citicorp and St. Peter's Lutheran Church, the original landowners, allowed Citicorp to build a structure on the site if it also constructed a church on the northwest corner of the block that would not be connected to the skyscraper in any way. To accommodate this requirement, LeMessurier devised an innovative structure in which the skyscraper rested atop a central core and four immense 114 ft (34.8 m) columns set at the midpoint of each side of the building. This design made it possible for the structure's corner to be cantilevered over the new church on the northwest, and it created an open plaza on the southwest corner.
LeMessurier's design also included a unique wind brace system comprising 48 braces arranged in a six-tiered V pattern on each side of the building. The system was intended to enhance the structure's lateral stability by channeling stress from the building's corners to the steel support columns at the center of each facade.
In June 1978, one year after construction of the skyscraper was completed, LeMessurier received a call from an engineering student in New Jersey requesting more information about the design. According to the student's professor, LeMessurier had placed the columns incorrectly. In revisiting his calculations, LeMessurier became aware of a serious flaw in the building's design.
At the time, New York City's building code required testing of a building's resistance only to perpendicular winds. Yet the placement of the support columns at the midpoint of each facade, rather than at the corners, meant that a greater risk to the structure's stability was presented by diagonal winds. When LeMessurier tested his wind brace system against winds hitting a column at an angle of 45 degrees, he realized that the winds increased the tension in four of the eight affected girders by 40 percent, substantially more than he had anticipated.
The increase in tension on the wind brace system would not have been a significant concern to LeMessurier if he had not recently learned of an on-site modification to his original design. His design had specified that the diagonal girders be welded to the support columns at the center of each facade; however, since welded joints were both expensive and commonly regarded as needlessly strong, LeMessurier's New York office had approved a change to bolted joints. Even more troubling was the news that while American Institute of Steel Construction specifications required an extra safety margin in the strength of joints in structural columns, the people on LeMessurier's team had chosen to regard the diagonal braces as trusses, not columns; thus, the number of bolts securing the joints had not provided for this extra margin of strength.
As a result of these design flaws, LeMessurier estimated that the Citicorp Center would be able to withstand only a 16-year storm, not the 50-year storm the building had supposedly been designed for. The design had also included a tuned mass damper, which might have lessened the risk of failure, but the damper relied on electric power and thus would provide no protection in the event of a power outage. With hurricane season on the horizon, LeMessurier believed that the potential for strong diagonal winds presented a significant risk to the newly occupied skyscraper.
Questions:
Instructions: Weave your answers into an essay that summarizes the case, its ethical issues, and your opinion. Your page limit is 2 pages (double-spaced). Feel free to reference other sources about this famous civil engineering case study, but you must cite your sources. I expect this to be an individual, not group, effort.
Source: http://www.asce.org/question-of-ethics-articles/july-2007/
Members who have an ethics question or would like to file a complaint with the Committee on Professional Conduct may call ASCE's hotline at (703) 295-6061 or (800) 548-ASCE (2723), extension 6061. The attorneys staffing this line can provide advice on how to handle an ethics issue or file a complaint. Please note that individual facts and circumstances vary from case to case and that the general summary information contained in these case studies is not to be construed as a precedent binding upon the Society.
Explanation / Answer
Q ) 1. In light of his discovery of a serious flaw in the Citicorp Center design, what were LeMessurier's obligations under the ASCE Code of Ethics?
A )Case Summary :
LeMessurier devised an innovative structure in which the skyscraper rested atop a central core and four immense 114 ft (34.8 m) columns set at the midpoint of each side of the building. This design made it possible for the structure's corner to be cantilevered over the new church on the northwest, and it created an open plaza on the southwest corner. In revisiting his calculations, LeMessurier became aware of a serious flaw in the building's design. As a result of these design flaws, LeMessurier estimated that the Citicorp Center would be able to withstand only a 16-year storm, not the 50-year storm the building had supposedly been designed for.
The guidelines provide ad etailed explanation of engineers job description : is that they should recognize the safety and importance of protection to the lives.Welfare of the general public and being ethical to their profession.If there is a evident risk to public safety,Lemessurier hasa n ethical reason and took steps to remove the threat.He notified the building owners the flaws in the design and the serious risks involved in the construction.The building can be posed to public safety.He designed the buidling by welding steel plates.He suggested to install to power system to damper the stress gauges and allows to constant monitoring the buidling consition.
Q ) 2. What would you have done if you determined that the revised probability of failure was higher (i.e., worse) than for the original design, but still within the range permitted by code?
A ) If I determined that the revised probability of failure was higher (i.e., worse) than for the original design, but still within the range permitted by code- I would redesign my design ,even if its in the permitted range of construction.I would strive to work for better future and ensure better safety standards for generations to come.
Q ) 3. What would you have done if your insurance carrier had said to “keep quiet”?
A ) I would complain and request higher authorities regarding the severe damages it can cause. I would explain the intensity and the flaws in the designs that can destroy the entire reputation of the company and this can lead to th eclosure of the company.This is because in future , the authorities and competitiors may enforce strict laws to judge the quality and safety measures of the constructions.
Q ) 4. What would you have done if the building owner, or the city, had said to “keep quiet”?
A) I would complain and request higher authorities regarding the severe damages it can cause. I would explain the intensity and the flaws in the designs that can destroy the entire reputation of the company and this can lead to th eclosure of the company.This is because in future , the authorities and competitiors may enforce strict laws to judge the quality and safety measures of the constructions.
Q ) 5. Who should pay for the repair?
A ) In my opinon the payment can be divided among the insurance companies , construction companies.
Reference :
http://www.asce.org/question-of-ethics-articles/july-2007/
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