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. 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.
It is recorded that the helical pier technology is more than 100 years old. Considered to be proven for new constructions and repairs or renovation works, this system is well used. For foundation repairs where soil condition would need installation to be deep piles, this system is proven to be very effective solution. 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. 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. Note that it is not wise to create additional structure on an existing structure.
The torque of each helical pier should be continuously monitored by the contractor during installation of the helicals. The contractor usually would know at the end of the installation the load or capacity of each pier since the capacity of each pier is directly related to the torque rating.
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. 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.
A word of advice, it is better to check structural engineer or repair foundation service to see which job is the right one for your project, especially each project could be different with various factors that will have an effect on the construction.
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