Kansas City Hyatt Walkway Collapse

Kansas City Hyatt Walkway turn over Introduction The Hyatt Regency Hotel was built in Kansas City, Missouri in 1978. This hotel consisted of a 40-story hotel towboat and conference facilities, which were connected by an open concept atrium. Inside the atrium, at that place were three paseos that connected the hotel to the conference facilities on the second, third, and 4th floors. The atrium was 145 feet long, 117 feet grand and 50 feet high. On July 17, 1981, approximately 2,000 great deal had gathered in the atrium to introduce in and watch a dance contest.Dozens stood on the walkways. At 705 PM, the walkways on the second, third, and fourth floor were packed with visitors as they watched over the dynamical lobby, which was also full of people. The fourth floor bridge was hang at ace time over the second floor bridge, with the third floor walkway doctor off to the side several meters away from the other two. Construction issues lead to a subtle but flawed material bod y change that duple the load on the connection between the fourth floor walkway support beams and the tie rods carrying the weight of the second floor walkway.This new see could barely handle the dead load weight of the structure itself, untold less the weight of the spectators standing on it. The connection failed and both walkways crashed one on top of the other and then into the lobby below, killing 114 people and injuring more than 200 others. Mainbody FIG-1 FIG-2 Originally, the 2nd and 4th floor walkways were to be suspended from the same rod (as shown in fig-1) and held in place by ens.The feeler design sketches contained a note specifying a strength of 413 MPa for the hanger rods which was omitted on the net structural drawings. Following the general notes in the absence of a condition on the drawing, the contractor phthisisd hanger rods with only 248 MPa of strength. This original design, however, was highly unfunctional beca social function it called for a nut 6. 1 meters up the hanger rod and did not use sleeve nuts. The contractor modified this detail to use 2 hanger rods sort of of one (as shown in fig-2) and the engineer approved the design change without checking it.This design change doubled the stress exerted on the nut under the fourth floor beam. Now this nut supported the weight of 2 walkways sooner of just one Conclution FIG-3 FIG-4 Neither the original nor the as-built design for the hanger rod genial the Kansas City make code making the connection failure inevitable. If, however, the building design had contained more redundancy this failure may not substantiate resulted in the complete collapse of the walkway.Kaminetzky (1991) suggests two much stronger design alternatives for the connectors. The toe-to-toe channels used in the Hyatt Regency provided for weak welding which allowed the nut to draw off through the channel/box beam assembly initiating the collapse. A straight channel design using web stiffeners when necessa ry (fig-3) or the use of bearing crossplates in conjunction with the toe-to-toe channels (fig-4) would have do the connection much stronger making it much more difficult for the nut to pull throughReferences Engineering Ethics Lessons Learned Kansas City Hyatt Walkway render http//www. pdhengineer. com/Course%20Web/Law%20and%20Ethics%20Courses/hyatt_walkway_collapse. htm Hyatt Regency Walkway Collapse. School of Engineering, University of Alabama. http//www. eng. uab. edu/cee/faculty/ndelatte/case_studies_project/Hyatt%20Regency/hyatt. htmCauses Kaminetzky, Dov, jut out and Construction Failures Lessons from Forensic Investigations (1991). McGraw-Hill, New York, N. Y.