The CHANCE® Helical Pulldown® Micropile Installation Process
Hubbell® is the world’s leading helical anchoring and foundation manufacturer. Backed by over 100 years of engineering experience. The CHANCE® helical pile system is a patented, deep foundation solution that is cost effective and offers higher capacity than standard helical systems.
The Process is Simple
- The screw pile is placed in the soil by applying torque to the shaft.
- The helical shape of the bearing plates creates a pulling force that keeps the helical piles advancing down into the soil. The helical pile is not an auger, but screws in with little disturbance to the soil.
- After the lead section penetrates the soil, a lead displacement plate and extension shaft are bolted onto the lead shaft.
- A grout reservoir is placed at the surface. This reservoir can be PVC pipe, steel pipe, laminated fiber tube, or other construction materials.
- Resuming torque on the assembled shaft advances the helical plates, pulling the displacement plate into the soil. This forces soil outward to create a cylindrical void around the shaft.
- The void is filled immediately by the gravity flow of grout from the reservoir above to surround and encapsulate the shaft.
- Additional extension shaft and displacement plates are added until the helical bearing plates reach load-bearing soil.
- This displacement method does not require the removal of any soil or spoils from the site.
- Skin friction mobilized along the grout column proved additional load capacity – a true composite pile, combining both friction and end bearing components.
The CHANCE Helical Pulldown® micropile can achieve high capacities in various soft, loose soils overlying competent load-bearing strata. Whether you are underpinning an existing structure that has settled, needing a high capacity foundation for a limited access site, or even building a new structure on poor surface soils, installing CHANCE Helical Pulldown micropile gives you a cost effective deep foundation solution.