Helical Pulldown® Micropiles (HPM)
The CHANCE® Helical Pulldown® Micropile (HPM) is used to form a grout column around the shaft of a standard helical anchor/pile. The installation process can employ grout only or grout in combination with either steel or PVC casing.
To begin the process, a helical pile is placed into the soil by applying torque to the shaft. The helical shape of the bearing plates creates a significant force that keeps the foundation advancing into the soil. After the lead section with the helical plates penetrates the soil, a lead displacement plate and extension are placed onto the shaft. Resuming torque on the assembly advances the helical plates and pulls the displacement plate downward, forcing soil outward to create 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.