• Tension load tests on 18-in-diameter (457.2 mm) ACIP piles to maximum test loads of 220 to 300 tons (1,957.2 to 2,668.9 kN) Prior successful experience with installing single-level O-cells into smaller diameter ACIP piles at similar depths at other project sites proved crucial in adapting the existing technology to the larger-diameter ACIP test piles in a multilevel arrangement. Special installation techniques are necessary when installing O-cells into ACIP piles in comparison to drilled shafts. For example, ACIP pile testing requires proper grout mix design to allow installation of the O-cells and special connection details between the O-cells and the reinforcing cage and vertical reinforcing cage assembly. Full-length reinforcing cages installed into the Met 2 ACIP piles ACIP Innovation Ultimately, the team selected a 120-ft-long (36.6 m), 36-in- diameter (914 mm), 1,000-ton (8,896.4 kN) compressive capacity ACIP pile for support of the Met 3 and Met 2 towers. Because of the innovative nature of this pile, the engineers implemented an early phase test pile and load test program to confirm the viability of installation of this pile, the “state of the art” at that time for ACIP piles in terms of length, diameter and capacity. The early phase test pile and load test program consisted of several method piles, a “world record” multi-level Osterberg (O-cell) embedded-jack load test to an equivalent top load of 5,200 tons (46,261.5 kN), a single- level O-cell load test, a cross-hole sonic logging test pile, and communication or grout-connection assessment piles. The early-phase program confirmed that the contractor’s equip- ment and methods were capable of installing the ACIP piles into the subsurface materials to the required depth of 120 ft (36.6 m), with full length reinforcing. The testing results allowed for an increase in the pile compressive design capacity to 1,200 tons (10,675.7 kN). In addition to the early-phase test pile and load test program, numerous conventional top-load tests and single-level O-cell load tests were performed as part of the design verification program for the different pile diameters and capacities used throughout the Met Miami development. The single level O-cell tests on 36-in-diameter (914 mm) and 24-in-diameter (609.6 mm) ACIP piles at the Met 2 project site were conducted to equivalent top loads of 3,680 tons (32,738.9 kN) and 1,600 tons (14,234.3 kN), respectively. The top load tests included the following: • Compression load test on a 24-in-diameter (609.6 mm) ACIP pile to maximum test loads of 1,000 tons (8,896.4 kN) • Tension load tests on a 24-in-diameter (609.6 mm) ACIP pile to maximum test loads of 420 tons (3,736.5 kN) • Lateral load test on a 24-in-diameter (609.6 mm) ACIP pile to maximum test loads of 15 tons (133.5 kN); • Compression load tests on 18-in-diameter (457.2 mm) ACIP piles to maximum test loads of 500 to 550 tons (4,448.2 to 4,893.0 kN) 10 • DEEP FOUNDATIONS • MAY/JUNE 2012 Quantities and Capacities ACIP pile drilling equipment at Met 2 site The ACIP piles installed or to be installed as part of the Met Miami development are as follows: • 550, 24-in-diameter (609.6 mm) piles and 200, 18-in-diameter (457.2 mm) piles were installed for the Met 1 development • 333, 36-in-diameter (914 mm) piles and 18, 18-in-diameter (457.2 mm) piles were installed for the Met 2 development • 50, 36-in-diameter (914 mm) piles, 272, 24-in-diameter (609.6 mm) piles, and 195, 14-in-diameter (355.6 mm) piles are currently planned for installation as part of the Met 3 development Based on the extensive O-cell load testing information obtained as part of the testing programs for the Met 3 and Met 2 projects, and building code revisions regarding allowable stresses, the 600-ton
