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. Especially if the work requires on existing buildings, helical piers would have competitive advantages over other systems.
Equipments that are used in helical piers foundation are usually smaller, lighter and less specialized compared to the equipment used in deep foundations. With these conditions, the cost of mobilization or the move in and move out, is generally lower compared to the other systems. Tight and confined areas are then more accessible to contractors when installing helical piles because of the specifications, while the larger equipment simply cannot 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.
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.
After installation, there is no curing time in the case of helical piers installation. Minimal excavation will suffice in a helical pile because it is turned 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. 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.