Abstract:
This presentation is a case study concerning upgrades to a YWCA building in Toledo, Ohio. The original design called for micropiles to be installed in the lower level of the building, within the existing swimming pool and the surrounding pool deck, to support columns for improvements to the superstructure. Challenges included limited access and headroom while requiring relatively highly loaded piles. The bidding foundation contractor priced the micropile design, but also joined with a designer to offer a helical pile solution at significantly less cost. The alternative design using helical piles was accepted.
Prior to production pile installation, a test pile was installed and dynamically tested to confirm that piles installed to the design torque could support the structure loads. During production some piles did not achieve the anticipated penetration depth but reached the design torque. Additional dynamic testing was performed on multiple piles to confirm the adequacy of the piles that had not reached the design depth. The load testing was completed successfully in difficult conditions. Ultimately, the use of helical piles provided significant cost savings to the owner.