How Stabilis®  Helical Slab Piers Work

Helical piers are end bearing and side loading foundation elements meaning the load is transferred down the solid square steel shaft into helical bearing plates and into load bearing soil. By applying torque to the shaft, the helices penetrate the soil by minimally displacing the soil on either side of the helices. The friction that is created between the helical plates and the soil during installation requires torque to install it into the soil. The torque that it takes to install the helices is measured and correlates back directly to the capacity of the pier. The whole process begins with an 8” dia. core drilled hole. The helical shaft is torqued into the ground using a hydraulic power pack and planetary drive motor. It is connected under the slab to a slab bracket that rest under the slab. The helical pier shaft transfers the load the full length of the shaft to the helices that are contacting the soil below. This occurs during the lifting process. Then the void below is grouted with non-shrink grout forming a bell around the helical shaft.