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.
It is recorded that the helical pier technology is more than 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. Hence, the cost of mobilization or the move in and move out is usually lesser as against the 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.
Another advantage of helical piers is that its installation is vibration free, and this is because they are turned in with a torque motor, a procedure similar to a wood screw being turned into a piece of wood. Be aware that it is not wise to add structures on an existing structures close by.
It is advisable for the contractor to be monitoring the torque it is required when installing each helical pier. The capacity of each pier is directly related to the torque rating, therefore the contractor will know at the end of each installation the load or capacity that a pier can support.
Note that helical piers can be immediately loaded after installation, meaning there is no curing time after installation. Because helical piers are screwed in or turned, minimal excavation is sufficient. 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. Contractors also use the helical piers under the existing foundation, rather than remove and disposal it in a landfill, and when this is done, there is a deep foundation system that is created contributing to the 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.