17-518: The First National Bank Tower is a 634-foot (193 m), 45-story office skyscraper located in downtown Omaha, Nebraska , United States, and the official headquarters of First National Bank of Omaha . It is the tallest building in Omaha and the state , and has been since its completion, overtaking the 30-story Woodmen Tower located nearby. Construction began in April 1999 and lasted until 2002, with
34-581: A fountain. The lobby also includes the original terracotta facade from the former Medical Arts Building along the lobby's southern wall. Following the completion of the building, its use of cast-in-place concrete and steel during the construction of the building's framework was the recipient of the Nebraska Chapter ACI Award of Excellence for Use of Concrete, the Engineering Excellence Honor Award from
51-721: A height of 634 ft (193 m) and 45 stories in total. The building was designed to be three feet higher than both the 801 Grand building in Des Moines and the Gateway Arch in St. Louis, making the final project the tallest building in the Midwest between Denver and Chicago . In 2022, Mutual of Omaha announced plans for the Mutual of Omaha Headquarters Tower . This building has been described by CEO James Blackledge as "on
68-471: A new headquarters. In 1997, the engineering firm Leo A Daly was selected to design the tower. Kiewit Corporation was chosen as the general contractor, and the construction cost was $ 225 million. The project was announced to the public in 1998. The First National Bank Tower was built on the site of the former Medical Arts Building, which was imploded on April 2, 1999, to make way for the current skyscraper. In April 1999, Kiewit formally began construction on
85-455: A parking garage nearby. Underneath the building is a series of tunnels that connect the parking garage to the main building. Lightweight concrete on metal decks was used to form the floor slabs of the building. This was done to minimize dead loads and support planned office and storage spaces. A two-hour fire-rated floor was constructed with 5.25 in (13.3 cm) concrete. The perimeter girder slabs were reinforced with steel, while
102-443: A pile cap is a "raft", which is a concrete foundation floor resting directly onto soft soil which may be liable to subsidence . The mat is made of concrete which is an aggregate of small rocks and cement . This mixture has to be supported by a framework to avoid sagging and fracture while setting. This process is known as shuttering and reinforcing . The materials used are long steel bars with longitudinal protrusions between
119-426: Is a thick concrete mat that rests on concrete or timber piles that have been driven into soft or unstable ground to provide a suitable stable foundation. It usually forms part of the deep foundation of a building, typically a multi-story building, structure or support base for heavy equipment, or of a bridge. The cast concrete pile cap distributes the load of the building into the piles . A similar structure to
136-675: The Nebraska Chapter of ACEC , and National Finalist Recognition by the national ACEC organization. The building also won fifth place for the 2002 Emporis Skyscraper Award . Downtown Omaha Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.150 via cp1114 cp1114, Varnish XID 917561750 Upstream caches: cp1114 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 08:44:25 GMT Pile cap A pile cap
153-414: The building are two fountains, with a third one located in the tower's front plaza. The lobby was built to feature a 60 ft (18 m) glass winter garden, constructed with bowed tube trusses and a curved cast-in-place concrete wall. The wintergarden also contains a mezzanine that leads to the building's second floor. This is supported by two tapered, cantilevered , cast-in-place concrete supports from
170-678: The building's completion being the subject of ACEC and Emporis awards. The construction of the tower and its parking garage heavily utilized cast-in-place concrete . Inside, the tower features a winter garden and the original facade of the Medical Arts Building, which was torn down to make space for the First National Bank Tower. In the 1970s, the First National Bank of Omaha outgrew its original headquarters and began drafting plans for
187-526: The building. Between May and June 1999, " Big Stan ", the world's largest drilling rig, was brought in to drill the caissons and foundation. On January 23, 2001, the structure's core passed 467 feet, overtaking the Woodmen Tower's record of 458 ft (140 m) at the time and making the First National Bank Tower the tallest building in Nebraska. The building was officially completed in 2002, with
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#1732783464966204-497: The pile cap took 11 hours of continuous concrete pouring and was the "largest single placement of concrete in the state of Nebraska". The foundations of the building were supported by 28 shafts, 90 in (230 cm) in diameter, that were drilled in the limestone bedrock by the Big Stan drilling rig. The steel support structure of the parking garage was encased in concrete to emulate a cast-in-place style of construction, while
221-417: The piles held in shape by thinner tie wires. Once this steel mat is laid, timber is attached around the perimeter to contain the wet concrete mixture. Once poured, (usually as a series of small loads), the concrete is stirred to remove any air pockets that might weaken the structure when set. The concrete undergoes a chemical change as it hardens and this produces a lot of heat. Sometimes, if the mass of concrete
238-405: The rest of the parking garage was built with cast-in-place concrete. This was done because the design lacked expansion joints , separation joints, and post-tension concrete; thus, the concrete design was connected to form one single structure. The parking garage was supported by 70 ft-deep (21 m), 30–60 in-diameter (76–152 cm), drilled shafts with cast-in-place concrete. Inside
255-400: The rest were reinforced with synthetic fiber . Exterior steel columns were spaced at 10 ft (3.0 m) around the building's perimeter, and composite wide-flange beams extended 47 ft (14 m) between the building's core and the exterior columns. The original core plan had dimensions of 91 ft 5 in × 39 ft 6 in (27.86 m × 12.04 m). The core
272-427: The scale of the First National Bank tower" and estimated to either be the same height as or overtake First National Bank Tower as the tallest building in the state. The First National Bank Tower follows a postmodern design with a granite facade. Externally, the building has a central tapering structure and an upward-curving base along its eastern side. The bottom six stories are designated as the building's base and host
289-418: Was a self-climbing style, housed an elevator shaft, and was constructed with 8000-psi (approximately 5.5 million pascal) concrete to provide lateral resistance to the structure. The core was supported by a 120 ft × 76 ft × 12 ft (36.6 m × 23.2 m × 3.7 m) concrete pile cap and 950 tons (862 metric tons) of steel to combat shear and uplift forces. Construction of
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