The façade for the University of Kentucky’s Kroger Field was cast in 87, 8-inch-thick architectural precast concrete panels, reducing the number of pieces and bearing points.
lery space. A prominent design feature is the high-performance precast concrete long-span roof joists that support a series of gabled skylights. To extend that aesthetic, the architects designed a series of 200 thin, closely spaced precast concrete roof joists, ranging from 6 feet to 55 feet, that span north to south between perimeter steel and interior con- crete wall elements to support additional skylights. A system of thin steel purlins runs east-west over the top of the precast concrete roof joists to provide lateral bracing to the joists. Precast concrete producer was BPDL – Bétons Préfabriqués du Lac, QC, Canada; Engineer of record was Guy Nordenson and Associates, New York. A 15-month, $50 million renovation transformed a neglected 10-acre civic space that was bisected by two of Cleveland’s busiest streets into a park-like destination that now provides a centerpiece to the city’s ongoing redevelopment efforts. The project included 1,300 individual precast concrete elements, including low linear walls to frame the perimeter gardens, and continuous, sinuous walls as tall as 8 feet to frame the Key Bank Promenade at the center of the square. The precast concrete walls were also used to create artificial topography. The precaster, Tectura Designs, a Wassau Tile Inc. brand, Rothschild, Wis., created 800 custom molds, including one to support a 9-foot-tall, 20,000-pound precast concrete piece. Engineer of record was Osborn Engineering, Cleveland. Transportation projects The Carriage Pavilion Bridge at Union Station, Kansas City, Mo., was selected as the top project in the Main Span up to 75 Feet category. Burns & McDonnell was design-builder of a new bridge to carry vehi- cles and pedestrians from the front of Union Station to the third level of the West Yards parking structure. Designers used precast, prestressed concrete spread box girders in long spans ranging from 33 feet to 75
feet for the superstructure system. To repel pigeons, the rectangular box-beam shapes were fully enclosed in concrete diaphragms at the pier caps. For drainage, designers “warped” the bridge deck toward a single downspout hidden behind one bent. A series of drain inlets were then placed in the vehicular roadway to receive water, including water flowing through open slots in the median barrier from the pedestrian path. The precast concrete producer was Coreslab Structures (Kansas), Kansas City, Kan. In the Main Span from 76-149 Feet category, judges selected the Inter- state 85 Bridge over Piedmont Road project in Atlanta. On March 30, 2017, a massive fire destroyed an elevated portion of I-85, causing part of the highway to collapse. Along with the collapse, the heat of the fire caused significant damage to the cast in place and precast concrete and superstructure, as well as the intermediate piers supporting the spans in both directions. The Georgia Department of Transportation’s new de- sign included 61 precast, prestressed concrete bulb-tee bridge girders, and due to the geometry of the spans, only nine could be duplicated. The project also required 13 concrete columns, four concrete caps, and removal of 13 million pounds of debris. By May 12 — 44 days after the fire and more than 30 days ahead of schedule — the project was com- pleted, and the new bridge was opened for traffic. The precast concrete producer was Standard Concrete Products, Savannah, Ga. Winning the Main Span more than 150 Feet category was the Chief Joseph Dam Timber Truss Bridge Replacement, Douglas County, Wash. The original 309-foot-long timber bridge consisted of a single, 130-foot-long by 20-foot-deep Howe truss, with five timber girder ap- proach spans. It was registered as a National Historic Place because of its rarity, structural form, size, and age. Despite rehabilitation in the early 2000s, the bridge had major structural deficiencies and needed to
33
april 2018
csengineermag.com
Made with FlippingBook Annual report