Proceedings of the 42nd Annual Conference on Deep Foundations, 2017, New Orleans, LA, USA, (DFI)
High-Capacity Driven-Pile Foundation for 33-Story High-Rise in Milwaukee, Wisconsin, USA
Van E. Komurka, P.E., D.GE, F.ASCE, William H. Walton, P.E., S.E., F.ASCE, Ryan C. Rusk, P.E., M.ASCE and Patrick J. Hannigan, P.E., M.ASCE
The project consists of a 33-story building with two levels of below-grade parking across the entire building footprint. Timely and cooperative teamwork among the owner/developer, geotechnical engineer, testing agency, structural engineer, construction manager, and pile-driving contractor resulted in an efficient, cost-effective, high-capacity driven-pile foundation on a constrained urban site with significantly variable subsurface conditions. Design objectives included utilizing the highest allowable pile loads reasonably installed from a drivability perspective, using readily available equipment. A pre-production test program was performed on 16-inch-diameter (406-mm-diameter) steel pipe piles, driven closed-ended and subsequently filled with concrete. The test program included dynamic monitoring of 10 piles during installation, and of select piles during long-term restrike testing with a drop hammer, with one instrumented static load test. CAPWAP® analyses were performed on both end-of-initial-drive and beginning-of-restrike dynamic test records. The site exhibited significant soil set-up, even after relatively short wait times. Test-program objectives included characterizing set-up profiles. A design set-up profile was used to develop depth-variable driving criteria for both 500- and 600-kip (2,224- and 2,669-kN) allowable load piles. Test program results permitted more-accurate reduced capacities to be assigned to damaged piles, and to piles which experienced practical refusal. These more-accurate assigned reduced capacities decreased the number of replacement piles required by 50 percent, saving both time and cost.
|article #2791; publication #1037 (AM-2017)|