The Tower at First National Center - Omaha, Neb.
Completed on time and under budget by Kiewit Construction Company, a subsidiary of Kiewit Corporation, the 46-story granite-and-glass Tower at First National Center forever changed Omaha's skyline. The project's scope of work included a 633-ft.-tall office building; a 300-stall, seven-level attached parking structure; two underground tunnels; and a 10,000-sq.-ft. Winter Garden. Preparation for construction began with foundation work for the giant pile cap. The Tower's elevator shaft is supported on 28 90-in.-dia. drilled shafts, which are socketed into bedrock. Each shaft is approx. 63-ft. deep and contains 100 cu. yd. of concrete.
Once excavation was complete, crews poured the 120-ft. by 76-ft. by 12.5-ft.-deep pile cap. This was Nebraska's largest continuous concrete pour ever, taking 11 hours to complete. Kiewit provided quality control services and construction design to ensure that the 1.9 million lb. of reinforcing steel would be held firmly in place throughout the pour. After the pile cap was poured, wall pours on the central core commenced. Nearly 330 cu. yd. of concrete were placed into wall forms to an average height of 13 ft. 6 in. With the concrete core topped out, crews installed the last of the structural steel and the building's exterior skin, which comprised hundreds of unitized aluminum, glass and Italian granite panels.
For its exemplary safety record and participation in the Occupational Safety and Health Administration's Voluntary Protection Program, the Tower project received the highest level of achievement - "Star" status.