Underpinning with helical piers is accomplished by extending the foundation in depth or width so it either rests on a more supportive soil stratum or distributes its load across a greater area. Use of steel piers, helical anchors and micropiles are the most common methods in underpinning.
Helical pier underpinning a foundation requires a steel bracketing system to connect the helical pile to the existing foundation. Foundation brackets come in many styles and configurations depending on structural requirements. Engineered eccentric brackets are the most common style of underpinning bracket. These brackets are engineered to be placed along the side of the foundation and transfer the foundations load to the pile member. This type of helical underpinning system can support ultimate loads of over 100kips.
Another style of underpinning brackets is the use of concentric brackets. These brackets are installed directly under the foundation and are in-line with the pile. Due to limited access under the concrete footing pier section must be shorter and thus installation generally takes longer than eccentric brackets.
As the above definition of underpinning states, “Underpinning is accomplished by extending the foundation in depth or width…”, the goal is to develop load bearing on deeper or more stable soils. ECP has developed and patented several styles of piling systems to meet this requirement. ECP Helical pier underpinning systems allow contractors to move beyond active soils that can move with fluctuations in temperature or moisture levels. Being able to get past these active soils is the key to permanently underpinning a structure.
Once the foundation repair piles are installed, often times, there becomes a need to lift the structure back to designed elevation. Lifting a structure is a very complicated and delicate process that should only be attempted by a trained foundation repair expert. ECP recommends that a registered professional engineer monitors all structural activities. Most engineering firms require that a structural lift only be performed with a hydraulic manifold system. ECP has developed the most extensive manifold lifting system in conjunction with Enerpac hydraulic equipment. This lifting system was designed for the precise control and stability required during a structural lift.
ECP Helical Piers are a top choice for foundation repair contractors and foundation design engineers for underpinning. For more technical information about the ECP helical pier products, go to the ECP Engineering section.
