Torque-installed piles are gaining popularity in Southern California as the go-to deep foundation element for small- to medium-capacity loads in urban environments. The torque-installed pile is a displacement-based screwed pipe pile with a closed-end conical tip welded to the bottom of the pipe. Torque-installed piles are most efficient in loose to medium dense soils with high liquefaction potential. Where used properly, torque-installed piles can be installed faster, require less clean-up, and create less onsite vibration/disturbance than other pile alternatives. However, torque-installed piles are not applicable in all soil conditions and care must be used to apply the pile effectively in the correct subsurface environment. This paper will review current Southern California state-of-the-practice for torque-installed pile design and construction, potential roadblocks to successful installation, and available capacities from load tests.
Subjects: piles, torque-installed piles, deep foundation, load test
Author: Molly Winston, P.E. and Jason Buenker, P.E.