A total of 16 Ductile Iron Piles were installed in two working days to provide bridge abutment support on the North and South embankments along the Cheney Rail Trail. The abutments, measuring 8-feet wide and 16-feet long, were loaded to 18.6 kips per foot vertically and 1.3 kips per foot laterally.
Plans initially specified culvert replacement followed by backfilling to connect the north and south embankments along the former rail line. Helical Drilling was retained to provide Geopier Rammed Aggregate Pier support for the new culvert and fill. However cost-saving design modifications converted the culvert/grade-raise to a pedestrian bridge with abutment footings bearing atop the embankments. Working from the existing embankments now required treatment depths of over 50 feet – precluding the use of the Geopier system. As an alternate, Helical Drilling proposed a Ductile Iron Pile system as the most cost-efficient deep foundation solution to easily access the limited area on the existing raised embankment. The modular 5-meter long pile sections were staged on the embankment and friction piles were installed to depths of around 55 feet to penetrate the fill and terminate in the underlain dense sand.
Ductile Iron Pile Advantages:
- Ability to work in tight access with medium-sized excavator
- Modular system for ease of installation to depth atop an embankment
- Rapid installation