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. According to manuals, the shafts are made to bearing depth by twisting the shafts into the soil while the torque is monitored to an estimated 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. This system is proven to be a very effective solution for foundation repairs especially when the soil condition would need installation of piles to be deep. The helical system is proved to be advantageous over other systems especially if the work involves existing buildings.
Unlike deep foundations that require more specialized equipment, in the helical piers, the equipment used are usually smaller, lighter and less specialized. Hence, the cost of mobilization or the move in and move out is usually lesser as against the 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 turned in with a torque motor like a wood screw being turned into a piece of wood, and this makes helical piles vibration free when installed that gives it an advantage. 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. 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.
After installation, there is no curing time in the case of helical piers 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.
Since there are differences in any project, it is advisable to contact structural engineers to see what is the right method for your project.