Brief Description of a Helical Pier and its Uses
Deep foundation of underpinning elements that are constructed using steel shafts with helical flights are known as helical piers. In performing the construction, shafts are moved to a bearing depth by twisting them into the soil, and at the same time the torque is monitored to the pile capacity.
The technology of helical pier is over 100 years old. It is considered as a proven system in new constructions and repairs or renovation works. Where the soil condition requires deep piles for installing foundation repair, this system is said to be a very effective solution. The helical system is proved to be advantageous over other systems 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. Because of these features, the contractors can access to tight and confined areas to install helical piles versus the larger equipment which does not fit.
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. Remember that it is not advisable to work on additional structure on neighboring properties with already existing structures.
The torque of each helical pier should be continuously monitored by the contractor during installation of the helicals. 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. Since there are no spoils that are to be hauled away from the site, you save on the costs of removal and disposal.
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.
Aside from being used in new construction projects, another very important advantage of using helical piers is that they can be great alternative for projects with failed existing foundations. 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.
Since there are differences in any project, it is advisable to contact structural engineers to see what is the right method for your project.