Helical Pulldown Micropiles
Higher load capacities than ever now are achievable by the patented CHANCE Helical Pulldown™ Micropile technology. It continues to overcome obstacles to traditional foundation methods in a growing number of applications.
The CHANCE Helical Pulldown™ Micropile system constructs a grout column, (typically 100mm or 127mm in diametre) around the shaft of a standard Helical Pier Foundation System. This application is ideal for sites with weak soil conditions or where extra load capacity is required.
The installation process can employ grout only or grout in combination with either steel or PVC casing. To begin the process, a helical anchor/pile is placed into the soil by applying torque to the shaft. The helical bearing plates require significant force or torque to advance the helical pile into the soil. After the lead section containing helical plates penetrates the soil, a lead displacement plate and extension are placed onto the shaft. Torque is again applied on the assembly to advance the helical plates, which pulls the displacement plate downward, forcing soil outward and creating a cylindrical void around the shaft.
From a reservoir at the surface, a flowable grout immediately fills this void surrounding the shaft. Additional extensions and displacement plates are added until the helical bearing plates reach the minimum depth required, or competent load-bearing soil. This displacement pile system does not require removing spoils from the site.
Benefits of this system include:
- Resistance to buckling in weak surface soils
- Stiffer pile (deflects less at a particular load)
- Additional corrosion protection in aggressive soils