Assignment 2A the “Citicorp Center” Case
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The “Citicorp Center” Case Assignment 2a The “Citicorp Center” Case Case analysis _ Olofsson Ingrid & Papadopoulou Kornilia 1. Introduction In 1978 a 59-story tower, the Citicorp Center, made of aluminum and glass was added in the New York City’s skyline and would later remain in history as “a collapse that never happened” (Goldstein & Rubin, 1996, p. 333). The building has a unique design which was produced because of a site’s constraint. A church, (St. Peter's Lutheran church) owned and was located in one of the site's corners. After negotiations, they sold their air rights with the term that a new church was built in the same position while staying independent from the skyscraper (Vardaro, 2013, p. 2). To overcome those limitations, a rather unique design was implemented which would later on pose some difficulties. A more traditional approach would be uneconomical according to the structural engineer William LeMessurier (William LeMessurier-The Fifty-Nine-Story Crisis: A Lesson in Professional Behavior, 2017, 06:53). However, it is a fact that the tall building technology as well as wind engineering were quite advanced by the time the Citicorp building was built. Despite that, it’s design was unprecedented and at the forefront of its time. In the end, the building was a total 160.000 m² and the estimated cost was about 195 million dollars (Vardaro, 2013, p. 3). After its completion and occupation, a student named Diane Hartley contacted LeMessurier, after noticing a potential deficiency in the skyscraper’s structural strength towards quartering wind (Vardaro, 2013, p. 3). After investigating and confirming her allegations with some other discrepancies and realizing the imminent danger of collapse, he took action and eventually resolved the problem. Following is a list of people involved derived from research (Lago et al., 2018, pp. 734; Morgenstern, 1997; Postal, 2016): ● Contractor: HRH Construction Company (United States) ● Steel company (bolting proposal): Bethlehem steel 1 The “Citicorp Center” Case ● Owner: (Original) First National City Corp. (United States), (Since 2009) Boston Properties (United States) ● Project manager: W. Easley Hammer ● Architectural designer: Hugh Stubbins & Assoc. (United States) ● Assistant to Stubbins: Peter Woytuck ● Project architect: Emery Roth & Sons (United States) ● Structural designer: Tower, Church, and TMD: LeMessurier (United States) ● Structural consultant & Skyscraper expert: Leslie Robertson ● Managing principal for Citicorp in LeMessurier Associates’ Cambridge office: Robert J. McNamara ● Partner in charge of LeMessurier Associates’ New York office where the construction drawings for the tower were prepared: Stanley Goldstein ● Retail base: Office of James Ruderman (United States) ● Damping supplier: Designed, built, installed by MTS System Corp. (United States) ● Testing laboratory: University of Western Ontario Boundary Layer Wind Tunnel Lab. (Canada) ● Director of the wind laboratory and wind analyzer: Alan Davenport 2. Mapping On the next page, follows a mapping of the actions that were done during the different phases as well as the corresponding project management virtues and problems. 2 Junior consultants use the wrong coecients for the chevrons by treating them as trusses - Following the - It doesn’t seem that they regulation without followed any type of TURNING POINT adapting it to the monitor or control since current building many of the errors could (quality control error) easily be avoided A student observes a possible error in the building’s structural CLOSURE ability INITIATION PLANNING EXECUTION MONITORING & CONTROL - A customer discovers a mistake after the completion of the Bethlehem Steel proposes a building substitution from Welded (Quality management error) LeMessurier & connections to bolt Stubbins come up with Not communicated to a unique design for the LeMessurier, but to other skyscraper managers. - A decision was made to + Creative thinking for save time and labor without problem solving proper communication with the LeMessurier. The new solution initially saved $250.000 REWORK LeMessurier takes into Gets extra wind He acknowledges his He gets help from the The story isn’t made The building is nished account the student’s tunnel testing mistake, Gets help from city and expert welders public, due to and is capable of claim, recalculates, experts on skyscrapers. are hired. newspaper strike withstanding 200 year winds. nds the aws and + Have additional data Comes up with a solution + Expanding the scope to The near-catastrophe investigates further. to properly compre- and informs all the involved meet the new quality +/- Mass hysteria and chaos isn’t published until hend the magnitude of parties while proposing his standards on time is prevented but is not + Customer feedback the error solution ethically OK to withhold 1997. are taken into information from the public. - The information that were + Consulting expert disclosed could have acted account. Quality +Expert Judgment judgment. Should control is made as a paradigm for have been done other/similar projects. No earlier. - A level 1 quality control data for future “lessons is generally unaccept- learned” practices. able. The error should have been found during the construction. Rework makes the cost higher. IN BLACK: ACTIONS TAKEN IN BLUE: POSITIVE PRACTICES IN RED: NEGATIVE PRACTICES IN GREY: CONTROVERSIAL PRACTICES The “Citicorp Center” Case 3. Case Analysis 3.1 Course of events In the 70s, in the midst of a long period of economic malaise, the “First National City Bank” who would later be named Citicorp, decided to relocate. After five years of negotiations and for the price of $50 millions they acquired the desired lot (Kremer, 2002, p. 269; Vardaro, 2013 p. 2). The architect Hugh Stubbins together with the building engineer William LeMessurier were hired to create the Citicorp Building (later renamed Citigroup Center, currently 601 Lexington). As it was briefly mentioned, an unconventional design was adopted in order to comply with the church’s demands. More specifically, the 4 load-bearing symmetrical columns were positioned in the middle of each facade, rather than on the corners, a service core in the center, and the bottom of the building was raised 34,7 meters off the ground level (Morgenstern, 1997, p. 23). That created a quality “open-plan” public space and the lot’s full capacity was taken advantage of. To support the edges of the tower floors and create stability, a series of eight-story high cantilevered steel frames, which transferred the loads to the central core were added. These chevrons, which here acted as columns, were delivered in parts, which according to LeMessurier’s instructions, needed to be welded together (Lago et al., 2018, pp. 735; Postal, 2016, p. 9). The top of the construction is also very distinctive as a 37.6 meters high, 45° sloped crown is placed there (Lago et al., 2018, pp. 735). It houses an important technological element that was needed to handle the swaying of the building: a tuned mass damper (TMD). It was used to counteract and reduce the movement of the building which was caused by the wind. Because the top and bottom of the building would be so elaborate, the architect wanted to keep the building’s skin simple. For this reason, every structural element, such as diagonals had to be placed on the inside. That would come of assistance for its secret fix later on. However, roughly one year after the completion of the building, a student called Diane Hartley contacted the engineering office to ask some questions about the building design for a school project. She and her professor were questioning the stability of the building, since the stilts were not placed in the corners which would make the building stronger (Morgenstern, 1997, p. 23). She had also come across some differences between her calculations and the original documents which were provided to her for her thesis (Student 4 The “Citicorp Center” Case Saves Skyscraper | Diane Hartley Citicorp Center Interview, 2019, 11:45). She received the reply that the problem was solved by putting a tuned mass damping system on the top of the building. Her question motivated LeMessurier, though, to question and review his calculations and so he discovered that the student was correct (William LeMessurier-The Fifty-Nine-Story Crisis: A Lesson in Professional Behavior, 2017, 28:40). He had previously also found out that Bethlehem Steel, in order to save money and work, had exchanged the welds in the diagonal trusses for bolts (Morgenstern, 1997, p. 23). In addition, he realised that his team had treated the diagonal wind braces as trusses instead of columns, which made the joints weaker than they should be, since fewer bolts were used (Morgenstern, 1997, p. 24). LeMessurier then used a new windtunnel test, with assistance from the expert Alan Davenport. It showed that the building could withstand a 16-year storm, which would put the nearby neighbourhoods into risk resulting in hundreds of casualties. The mass damping system reduced this number to a 55 year storm, but it required electricity for function. The error was discovered in June, and hurricane season was imminent, giving them very little time margin for the rework (Morgenstern, 1997, p. 25). LeMessurier came up with a solution and contacted his insurance company, the architect and the client, Citicorp. Additionally an expert on skyscrapers, structural engineer Leslie Robertson was added. His background in disaster management was suitable in this situation. The newly formed team started a disaster plan, in order to reinforce the building. They contacted the mayor and the red cross, a communication plan, to prevent chaos. LeMessurier’s office also closely monitored the mass damping system, after installing a backup power generator, since it was an integral part of the stability of the building (Delatte, 2009, p.338). The placement of the trusses on the inside, helped the welders to work undetected every night. In the end, the extra cost for fixing the problem totalled to $8 million (Delatte, 2009, p.