Brief Description of a Helical Pier and its Uses
Known as helical piers are deep foundation underpinning elements that are constructed with the use of steel shafts with helical flights. By twisting the shafts into the soil with advanced bearing depth, the torque is also monitored to reach a pile capacity.
The technology of helical pier is over 100 years old. Considered to be proven for new constructions and repairs or renovation works, this system is well used. Where the soil condition requires deep piles for installing foundation repair, this system is said to be a very effective solution. Helical piers as compared to other systems will prove to be more advantageous especially if the work involves existing buildings.
Equipments that are used in helical piers foundation are usually smaller, lighter and less specialized compared to the equipment used in deep foundations. In this case, the cost of moving in and moving out or mobilization is usually lesser than other systems. These conditions allow contractors then to go in tight or confined areas in helical piles installation as compared to the larger equipment which cannot fit into the area.
Helical piers are also advantageous in the sense that they are installed vibration free because they are turned in with a torques motor similar to a wood screw that is turned into a piece of wood. Be aware that it is not wise to add structures on an existing structures close by.
The torque should be regularly monitored when contractors are installing helicals in each pier. Because the capacity of each pier is directly related to the torque rating, the contractor will know the load or capacity that each pier can support.
Note that helical piers can be immediately loaded after installation, meaning there is no curing time after installation. Also, there is minimal excavation required for helical piers that are turned on or screwed in. Another advantage of helical piers is that you save on costs of removal and disposal because there are not spoils to be removed from the site.
Note that with the use of smaller installation equipment like the helical piers, there is a drastic elimination of noise, like no violent hammering or banging.
Those existing foundations that are failing, can be solved using helical piers, and this is another very important advantage of helical piers, aside from being used in new constructions. Instead of removing the present foundation that failed and dispose it in a landfill, the helical piers are used over the present foundation, thereby creating a deep foundation system plus contributes to a green environment.
Several factors would affect your project, and so it is wise to ask the help of structural engineer to see which method would be best for your project.