The Veer and Pelli towers involve additional construction challenges. Veer consists of two towers, each rising 5 degrees off vertical, one toward the south and one toward the north direction. Each floor level is 6 inches out of plumb with the one proceeding, adding to the challenge of both layout and construction. There is more rebar congestion as a result and some reinforcement includes #18 bars (2¼ inches in diameter).

The Pelli Tower is the largest and tallest building onsite. It consists of two intersecting arcs, one 900 feet long and the other 993 feet long. The curving of the building and the intersecting arcs provide layout challenges. Floor areas started at 109,000 square feet and are now 70,000 square feet. Perini is completing a floor every seven days.

At the two intersection points of the arcs on each deck there are 6-foot “delay strips” running the width of the floor. Concrete is placed in these areas 21 days afterward to provide time for shrinkage so that the floors don't overly stress the columns. The floors also are post-tension reinforced so Perini includes five additional “stressing strips” that are 6 feet long, crossing the width of each floor. The tendons are stressed when concrete strengths reach 3000 psi—generally by the third day and the stressing strips then are filled with concrete four days later.

Though the site is small for the size of the development, it also feels enormous. There are 13 tower cranes and numerous track-mounted cranes. Several concrete pumps and placing booms serve the tower constructions and truck-mounted boom pumps serve the many low-rise areas. There are perhaps more “mules” (four-wheel drive transports for construction personnel) onsite than anyone can count.

At the present time, 80 subcontractors are working on the project and Grantham says that the number will greatly increase as construction proceeds. For now the workforce is 4800 construction workers but Grantham says the number eventually will rise to 7000.

With all the intense activity, the project is running smoothly. Absher says the whole team is working well together and there are ongoing discussions about keeping the team together for the next MGM development.

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Some of the main principals on the project include:

• Owner: MGM Mirage
• Executive architect: Gensler, New York City
• Primary contractor: Perini Building Co., Phoenix
• General contractors: Bomal, Anaheim Hills, Calif.; Ceco, Las Vegas; and Urata, San Francisco
• Caissons: Malcom, San Francisco; and Anderson Drilling, Lakeside, Calif.
• Formwork suppliers: Aluma Systems, Concord, Ontario, Canada; Doka USA, Little Ferry, N.J.; EFCO Forms, Des Moines, Iowa; Peri Formwork Systems, Elkridge, Md.; and Waco Scaffolding Equipment, Cleveland
• Ready-mix producer: Rinker, Las Vegas
• Concrete testing: Converse, Las Vegas; Kleinfelder, Las Vegas; and Terrcon, Las Vegas