Helical piles can be used in a variety of applications including compression, tension, new construction and underpinning. Helical piles are screwed into the soil and extensions are added until the desired capacity is achieved. To increase the lateral stability of the pier and its buckling resistance, the shaft may be encased with a steel or plastic pipe that is filled with grout. For underpinning situations, underpinning brackets are used to transfer loads from the foundation to the helical piles and are systematically stressed using hydraulic jacks until the foundation is totally supported on the piles.
Helical piles are available in a wide range of shapes and sizes with many different helical combinations available depending on the project requirements. The two basic shapes consist of RCS (rounded corner square) shaft piles which range in size from 1-1/2″ to 2″ square and pipe piles which range in size from 2-7/8″ OD to 8-5/8″ OD which are available in standard pipe schedule sizes. The helical combinations can also vary widely with single, double, triple and quadruple helical combinations available, with sizes of helices ranging from 6″ to 14″ in diameter.
Some attributes of the Helical Pile Underpinning System:
- Modular design which installs to any depth
- Environmentally friendly with no spoils
- Noise and vibration free installation
- Installs with readily available small equipment such as a mini-excavator or Bobcat®
- Predictable capacity in the field confirmed by installation torque
- Can be installed in close proximity to an existing structure