The Philadelphia Housing Authority had a housing community on Tasker Avenue in Philadelphia demolished for reconstruction. The foundations for the new structures had to bear in the alluvial soil below the urban fill that was left from demolition in order to ensure adequate support. The foundation options were complicated by both the depth and heterogeneous nature of the fill. In addition, the urban fill was classified as “regulated,” resulting in high disposal fees at a landfill. Conventional strip and spread footing would require being founded on properly compacted select load-bearing fill or competent native alluvial soils. This would have required over-excavation and back-fill. Disposal cost of the regulated fill made this cost-prohibitive. Similarly, drilled shafts were not economical due to the disposal cost of the spoils.
Project Summary:
- Helical Pile Type:1.75″ Square Shaft
- # of Helical Piles: 3,645
- Location: Philadelphia PA 19145
- Installation Depth: 15′ – 55′
- Equipment Used: CAT 315 w/ Eskridge 20,000 ft
- Challenge/Unique Aspect: Varying Ground Conditions
- Engineer/Architect: Pennoni Associates
- General Contractor: Keating Building Corp
