Helical Screw Piles
Helical pier or pile is a deep foundation element made of a steel shaft that can be solid square bar, tubular pipe or square tubing. Lead sections will have one to three helices welded to the shaft of the pile. The helices are equally spaced apart along the shaft based on the lead helix diameter. This allows the pile to be advanced into the soil by rotating without auguring the soil.
The resistance to advance the pile into the ground is measured by torque which has a correlation to the holding capacity of the pile.
Helical piles can be used in new construction, repair failing foundations. Gas and oil pipelines, boardwalks, solar foundations, street light foundations, lattice towers and many more applications.
The load being supported by the pile is transferred from the shaft to the soil via the helical bearing plates. Capacities for our helical piles range from 5 kips to 560 kips.
Hydraulically Driven Piles or Piers
Hydraulically driven steel piles are typically 2.87” or 3.5” diameter steel pipe that come in 3’,5’ 7’ and 10’ lengths. The steel can be galvanized, epoxy coated or plain steel. 2.87” diameter piles can be driven to a capacity of 80 kips and the 3.5” diameter material can be driven to a capacity of 100 kips.
The pile consists of a bracket, starter section, guide sleeves and extensions. The bracket is attached to the foundation. The starter piece with a frictionless collar and guide sleeve are placed in the bracket. Two drive cylinders are attached to each side of the bracket and a slip head with teeth grabs the pipe and forces it into the soil as the cylinders are retracted. Extensions are added to the pile until the ultimate design capacity has been achieved.
Soil Screws are typically a solid square bar shaft and consist of multiple helices of the same diameter for the entire length of the soil screw. Soil screws are typical drilled into lateral soil walls and used in conjunction with a shotcrete facing to create a gravity wall. Bearing plates are attached to the end of the soil screw and embedded in shotcrete.
Helical tiebacks are high capacity anchors that have their holding capacity monitored by torque just like a pile.
Helical tiebacks have many different applications. They are used to stabilize existing walls that are failing and moving. They can be installed in the preconstruction phase and as marine moorings. Tiebacks are installed in whalers through timber and lag and also sheetpiling. Tiebacks consist of a lead section with helical plates and extensions. The lead section is referred to as the bonded length that supports the load and the extensions are the unbonded length. At the termination of the tieback a threaded adapter is usually bolted on and some type of structural member, typically a steel plate designed to carry the load.
- All work is done from the outside of the home unless straightening the wall. If straightening the wall, cribbing needs to be installed on the inside. This means no intrusion into your home and no dust and dirt in your home from drilling and traffic.
- There are no holes drilled through the foundation to allow water to leak into your home.
- There are no unsightly bearing plates on the inside of the wall.
The system is Empire Piers 1.5” RCS material. Ultimate design of the system will be 18 kips, based on the current wall plate and anchor bolts recommended. Higher capacity can be achieved with larger diameter plates and bolts. Contact your representative for design assistance.