Ductile Iron Piles were recently installed at Vermont’s Waterbury State Office Complex as a cost-effective alternative to traditional drilled micropiles.
The reconstruction project included the construction of a heavily-loaded mat foundation used for a woodchip storage pit within the wood-fired biomass central plant. Performance of the mat foundation became a concern because of the presence of undocumented fill as well as a buoyancy issue arising because of a shallow groundwater table. Although initial project specifications required 8-inch drilled micropiles for compression and tension resistance, Helical Drilling proposed a more cost-effective approach using 118 mm (4.65 inch) diameter Ductile Iron Piles reinforced with a central reinforcing bar and grouted to provide frictional resistance for both tensile and compressive loads in the loose to dense sand below the fill.
WHEN TO CONSIDER USING DUCTILE IRON PILES
You are evaluating any of the following techniques:
- Helical anchors
- Micropiles
- Augercast piles
- Driven piles
You encounter one or more of the following geotechnical challenges:
- Poor soil conditions – deep soft soils, fills and organics
- Vibrations
- Adjacent structures
- Difficult access and constrained sites
- Low overhead