Structural Steel Underpinning – Keypoints
Underpinning can remedy a wide range of support problems that affect a building or slab. The challenge as with most stabilization methods is to get the Piles or “Piers” within and around the settled portion of an existing structure. Roof overhangs or low ceilings can often limit the use of most pile driving equipment. In cases where those methods can overcome the access restrictions, they typically use heavy machinery and end up destroying the surrounding landscaped areas.
Powerful & Compact Installation – Our system has been designed to overcome limited access restrictions while still delivering a compact but powerful pile installation. Each hydraulic ram that is used to push the piers into the ground is hand carried to the installation area from a van that is parked in your driveway. There is no heavy machinery used and there is not the noisy banging sound that is normally associated with pile driving equipment.Our installation method uses a quiet steady pressure from a hydraulic piston that advances the pile into the ground. To begin the installation we will hand excavate at each pier location to minimize the disruption to the site. We will excavate an approximate 3′ x 3′ area in order to attach the lifting bracket to your foundation or slab. After each pier has been driven and successfully load tested, the lifting rams are then connected together in a series, which allows us to simultaneously lift the structure back into place. After checking all elevations during and after the lifting process, the lifting brackets are then secured to the installed pile and the hydraulic lift units are removed. Once this work has been completed the entire work area is backfilled and cleaned up.
Load Testing – One of the main benefits with the CFI underpinning system is that every pile we install is load tested to achieve a safety factored bearing capacity. By using this sophisticated pressure test procedure we can virtually eliminate the chance of seating the pile into a false refusal zone. Each pile we install is typically driven to more than double the required service load. Simultaneous Lifting capability can help minimize the stress exerted on the building system during the re-leveling effort. We can locate these underpins at critical bearing points to help lift and re-level those settled portions of the foundation or slab. This will allow us to realign sticking doors or windows that may have been affected from the settlement damage.