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. 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. 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. Helical piers as compared to other systems will prove to be more advantageous 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.
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. 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.
Helical piers installation does not require curing after installation and they can immediately be loaded. Because helical piers are screwed in or turned, minimal excavation is sufficient. Since there are no spoils that are to be hauled away from the site, you save on the costs of removal and disposal.
There is not violent hammering or banging to install helical piers and this is a big advantage with regards to the reduction of noise.
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. There is also a contribution to the green environment when using helical piers, because instead of removing the existing foundation that failed and dispose it in a landfill, contractors would install the helical piers under the existing foundation thus there is a deep foundations system that is created.
Since there are differences in any project, it is advisable to contact structural engineers to see what is the right method for your project.