Excavation Structural Support
Waterloo, NY: Seneca Meadows Landfill, Single Auger Soil Mixing
- Soft ground improvement for the expansion of the 3rd largest active landfill in the US
- Second soft ground improvement project in a series of planned ground improvement projects
The Stage 7 Ground Improvement project was completed using a track mounted drill rig fitted with a large diameter auger to mix Portland cement in a water based grout with portions of a soft, underisable clay layer that underlies much of the Seneca Meadows Landfill. The Stage 7 landfill expansion is the newest expansion of this rapidly growing landfill which is the 3rd largest active landfill in the US. Soil mixing was selected over alternative ground improvement methods because of its ability to cost effectively improve the undesirable soils in timely manner.
Description of Work
- Installation of 295 nine foot diameter soil mixed columns
- Maximum depth of 20' BGS
- 290,000 cf of soft clay was stabilized with 2,500 tons of Portland cement
- Average UCS of stabilized clay was 285 psi after 14 - 28 days of curing
- 74 of the columns were cored using a "pitcher sampler"
- Work completed over 7 weeks
Key Project Objectives:
- Cover >20% of the surface area (aerial) with stabilized columns that extended above and below the known extents of the soft clay
- Ensure that the soil mix elements had a strength greater than 70 - 105 psi (two different target strengths).
- Achieving a well-mixed soil-reagent composite in the soft, plastic clay
- Working on the soft work platform