High Capacity Drilled Displacement Piles as an Alternative to Conventional Driven Methods-PPT Presentation

PPT Presentation

Pdf Summary

The Red Hook Houses redevelopment evaluated pressure-grouted drilled displacement piles as an alternative to conventional driven piles. The hybrid design used steel pipe piles with helical plates and grout; a double-steel-casing concept was proposed to address high lateral loads.<br /><br />The alternative substantially reduced required pile depths. For the West Building, the bid documents specified a minimum tip depth of 35 feet, while alternative piles were installed at about 39–41 feet. For the East Building, the original minimum was 110 feet, compared with alternative pile depths generally around 38–53 feet. Required capacities were 64 kips compression and 1.5 kips lateral for the West Building, and 210 kips compression, 60 kips tension, and 20 kips lateral for the East Building.<br /><br />Load tests showed the alternative could meet key project demands. West Building piles were compression-tested, and lateral testing was also performed. East Building lateral tests demonstrated 20-kip allowable capacity, with measured deflections of 0.44 and 0.47 inches. Compression testing included loads up to 678 kips, with 1.39 inches of gross settlement; the required ultimate capacity was 420 kips. Strain gauges were also used on one pile to measure load transfer to the surrounding soil.<br /><br />The presentation concludes that drilled displacement piles can be a viable, potentially sustainable substitute for driven piles. Potential advantages include reduced materials and labor, faster installation, no pile splicing, quieter construction, and eliminating vibration monitoring. The approach may require additional testing and design documentation, but hybrid pile methods can offer economical and faster construction solutions.

Keywords

Red Hook Houses

redevelopment

pressure-grouted drilled displacement piles

conventional driven piles

steel pipe piles

helical plates

double-steel-casing

load testing

lateral capacity

sustainable foundation solution