Helical piles for pre-construction, foundation to infrastructure support. Post-construction for leveling, lifting supporting of structures.
The term underpinning is synonymous with micro piles. Underpinning is the technology and method of secondary and remedial repairs to an already existing structure. Underpinning is not used in new construction whereas micro piles are used mainly in new construction.
What is Underpinning?
Underpinning is a remedial repair system that normally uses the weight of the structure with a hydraulic ram system to push steel pipe into the ground which gives an unstable structure additional support.
Underpinning transfers the weight of a structure to deeper soil strata of increased beating capacity in order to stabilize the structure from further settlement or movement.
Simply put you can think of underpinning as a steel pile system similar to a bridge or building piling to add additional support to a structure.
The main reasons for the use of underpinning in ground modification are:
1. Overcoming organic material
2. Stabilizing a structure affected by highly plastic clays
3. Lift, level and re-support a structure with extreme settlement
4. Stabilize a structure that has the possibility of major movement during the sinkhole remediation process. What separates NEC Keystone, Inc. from other companies who offer the same type of repair method are the following key elements:
1. We have the highest trained technicians in the industry on the project site performing the underpin procedure.
2. We have developed and manufactured all the components used in the underpinning procedure. We construct a bracket system that is the largest in the industry, measuring 30 inches wide, 8 inches deep and 6 inches in height. This enables our underpinning system to carry heavier loads and minimize the stress placed on the foundation, slab and wall systems.
3. We are the only company that uses a point designed (configuration) starter pipe to achieve the maximum depth possible during the installation of the underpin casing to a more suitable strata. We design and create the starter pipe to our exacting specifications in our on-site machine shop.
4. We use a three and a half inch schedule eighty pipe as the underpin component that is driven into the ground. This crucial piece is twice as heavy as the industry standard and provides additional support to the structure.
5. We grout the bracket in place when installing the bracket system. We follow this procedure using 10,000 PSI grout in order to remove any and all imperfections in the footer and to secure the lifting bracket for a continuous bearing onto the footer.
6. We are the only company that machines its pin pile segments for a metal to metal press fit. This is to ensure a stable, reinforced straight alignment of the foundation piles.
7. We are the only company with the knowledge and capability to completely handle leveling an entire structure simultaneously with up to 100 piles installed at once.
8. We are the only company who makes sure the rams are level and vertical in order to minimize any stress and momentary loads on the structure.
9. We are the only company that uses twenty ton hydraulic jacks during the installation of the pin piles and lifting procedure to stabilize the structure at all times to prevent any dramatic fluctuations of the structure.
10. We wait 24 hours after the piles are driven to load test the piles in order to ensure that all of the piles are seated. Only then do we begin the final welding process, dismantling of the driving systems and removal of excess pipe.
11. We maintain a clean, organized and safe project site at all times. This includes safety fencing along work areas that are not currently being worked on and at the end of each day.
12. We are the only company that, upon completion of a project, backfills the excavated areas and fills the underpin locations with a flowable fill cement. We fill the interior of the pipe in order to assure maximum compaction underneath the footer and to prevent any excess water entering into the pin pile location.