1987 –April 23, Construction collapse, L’Ambiance Plaza apt. bldg., Bridgeport, CT — 28
— 28 Carper and Feld. Construction Failure. 1997, p. 9.
— 28 Delatte. Beyond Failure: Forensic Case Studies for Civil Engineers. 2009, p. 107.
— 28 Exponent Engineering and Scientific Consulting. L’Ambiance Plaza.
— 28 Grant, Ellsworth S. “Houses of Cards,” Chap. 6 in Connecticut Disasters, 2006, p. 171,
— 28 Ward. “It was Gone: String of Problems Led to 51 Deaths at Willow Island.” 4-27-2008.
Narrative Information
Carper and Feld: “L’Ambiance Plaza, Bridgeport, Connecticut, April 1987. A 16-story post-tensioned prestressed concrete lift-slab apartment project collapsed suddenly during construction, resulting in 28 deaths.” (Carper and Feld. Construction Failure. 1997, p. 9.)
Delatte: “The death of 28 workers in the April 23, 1987, construction collapse of the L’Ambiance Plaza building in Bridgeport, Connecticut, triggered a massive rescue effort and several investigations. Unfortunately, to this day the true cause of the collapse remains in dispute because a settlement ended all investigations. This was a lift-slab project…. [p. 107]
“At the time of the collapse, the building was a little more than halfway completed. In the west tower, the 9th, 10th, and 11th floor slab package was parked in stage IV directly under the 12th floor and roof package… The shear walls were about five levels below the lifted slabs (Cuoco et al. 1992).[1]
“The workers were tack-welding wedges under the 9th-to-11th floor package to temporarily hold them in position, when a loud metallic sound followed by rumbling was heard. Kenneth Shepard, an ironworker who was installing wedges at the time, looked up to see the slab over him ‘cracking like ice breaking.’ Suddenly, the slab fell onto the slab below it, which was unable to support this added weight and fell in turn. The entire structure collapsed, first the west tower and then the east tower, in 5 s, only 2.5 s longer than it would have taken an object to free fall from that height. Ten days of frantic rescue operations revealed that 28 construction workers had died in the collapse, making it the worst lift-slab construction accident ever. Kenneth Shepard was the only one on his crew to survive (Levy and Salvadori 1992).[2]….
“All of these theories are plausible, but what triggered the collapse? The answer may never be known. A two-judge panel mediated a universal settlement among 100 parties, closing the L’Ambiance Plaza case. Twenty or more separate parties were found guilty of ‘widespread negligence, carelessness, sloppy practices, and complacency.’ They all contributed, in varying amounts, to the $41 million settlement fund. Those injured and the families of those killed in the collapse received $30 million. Another $7.6 million was set aside to pay for all of the claims and counterclaims among the designers and contractors of L’Ambiance Plaza.
“Although this settlement kept hundreds of cases out of court and provided rapid closure to a colossal collapse, it also ended all investigations prematurely, leaving the cause of collapse undetermined (Korman 1988).[3] Fortunately, many of the investigators subsequently published their findings (Feld and Carper 1997).[4] [p. 118] ….
“The L’Ambiance Plaza collapse highlighted several procedural deficiencies. Responsibility for design was fragmented among so many subcontractors that several design deficiencies went undetected. If the engineer of record had taken responsibility for the overall design of the building or a second engineer had reviewed the design plans, these defects probably would have been detected (Heger 1991).[5] Also, standardized step-by-step procedures for lift-slab construction should be established to ensure the safety of the construction workers. A licensed professional engineer should be present during construction to ensure that these guidelines are followed (Kaminetzkv 1991).[6]
“According to Zallen and Peraza, three structural engineers should he involved in the design and construction of a lift-slab building. These are the structural engineer of record, the lift-slab engineer, and the post-tensioning engineer. The structural engineer of record is responsible for the integrity of the building in its completed state. The lift-slab engineer, hired by the lift-slab contractor, designs the lift-slab process, including structural stability during lifting operations. The post-tensioning engineer details the tendons and related details and must coordinate carefully with the lift-slab engineer. All three engineers must coordinate their work carefully (Zallen and Peraza, 2004, pp. 62-63).[7] [p. 119] ….
“This failure severely reduced the use of the lift-slab system and almost eliminated it from use (Moncarz and Taylor 2000, p. 46)….”[8] [p. 121] (Delatte. Beyond Failure, 2009.)
Exponent Engineering and Scientific Consulting: “On April 23, 1987, 28 construction workers were killed when the 16-story L’Ambiance Plaza apartment building in Bridgeport, Connecticut collapsed during construction. Though the collapse has been studied by several prominent engineering teams and has been the subject of intense debate in the engineering community, there has been no consensus regarding details of the root cause. Exponent was retained on behalf of the concrete placement subcontractor to investigate the failure.
”The two adjacent towers of the building were being cast in a stack at grade level and then jacked up along steel columns into their final position. At the time of the collapse, slabs 3, 4, and 5 of the east tower had been placed into final position, and slabs 9, 10, and 11 for the west tower had just been lifted. A hydraulic jack was being used to plumb the two towers when both towers suddenly and completely collapsed. Because hard evidence was destroyed during rescue operations and because of the large number of deficiencies with the building construction, it is impossible to pinpoint one distinct reason for collapse.” (Exponent Engineering and Scientific Consulting. L’Ambiance Plaza.)
Ward: “…28…workers died in the collapse of the L’Ambiance Plaza, a 16-story apartment complex in Bridgeport, Conn. That disaster occurred on April 23, 1987…” (Ward 2008.)
Sources
Carper, Kenneth L. and Jacob Feld. Construction Failure. John Wiley & Sons, Inc., 1997. Partially digitized by Google. Accessed 11-11-2016 at: http://books.google.com/books?id=-jnlb-oJxcEC&printsec=frontcover&source=gbs_v2_summary_r&cad=0#v=onepage&q=&f=true
Delatte, Norbert J. Jr. Beyond Failure: Forensic Case Studies for Civil Engineers (pp. 107-121). Reston, VA: American Society of Civil Engineers Press, 2009.
Exponent Engineering and Scientific Consulting. L’Ambiance Plaza. Accessed 8-8-2009 at: http://www.exponent.com/lambiance_plaza/
Grant, Ellsworth S. “Houses of Cards,” pp. 169-174 (Chapter 6) in Connecticut Disasters: True Stories of Tragedy and Survival. Globe Pequot Press, 2006.
Ward, Ken Jr. “It was Gone: String of Problems Led to 51 Deaths at Willow Island.” WVGazette.com, 4-27-2008. Accessed at: http://wvgazette.com:80/News/WillowIsland/200804250422
[1] D. Cuoco, D. Peraza, and T. Scarangello. “Investigation of L’Ambiance Plaza Building Collapse,” Journal of Performance of Constructed Facilities, Nov, 1992, pp. 211-230.
[2] Matthys Levy, and Mario. Salvador. Why Buildings Fall Down: How Structures Fail. NY: W.W. Norton, 1992.
[3] R. Korman. “Mediated settlement seeks to close the book on L’Ambiance Plaza.” Engineering News-Record, Nov 1988.
[4] Jacob Feld and Kenneth L. Carper. Construction Failure (2nd ed.). NY: John Wiley & Sons, 1997.
[5] Frank J. Heger. Engineering.com, “L’Ambiance Plaza.” Posted 10-24-2006 at: http://www.engineering.com/Library/ArticlesPage/tabid/85/PageID/182/ArticleID/168/articleType/ArticleView/Default.aspx
[6] Dov Kaminetzky. Design and Construction Failures: Lessons from Forensic Investigations. NY: McGraw-Hill, 1991, pp. 78-85.
[7] Rubin M. Zallen and David B. Peraza. Engineering Considerations for Lift-slab Construction. American Society of Civil Engineers Publications, 2004.
[8] Piotr D. Moncarz and R. Taylor. “Engineering Process Failure — Hyatt Walkway Collapse.” Journal of Performance of Constructed Facilities, Vol. 14, No. 2, pp. 46-50, 2000.