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Types of Foundation Underpinning

Foundation Underpinning

Foundation underpinning or stabilization can be performed using several foundation repair methods, including piering, wall anchors or mudjacking. Piering can be performed with round shaft piers, square shaft piers, or concrete piles depending on the foundation stabilization situation and should be determined by a professional engineer at a reputable foundation company.

Foundation Piering or Piles

There's a big debate going on about round shaft piers versus square shaft piers. We believe each type of pier has a place depending upon the foundation stabilization situation. For compression applications JES utilizes round shaft piers and for tension applications square shaft piers are used.

We use galvanized steel piers and helical anchors for foundation underpinning, that have been evaluated by the ICC-ES. And these products are galvanized in accordance with ASTM A123 and ASTM A153.

Round Shaft Piers

Round shaft helical or resistance piers are designed for compression applications. Round shaft piers have a higher moment of inertia (resistance to bending) which makes them ideal for compression applications.

The round shaft piers also have a higher installation torque rating and a higher lateral resistance because there's a larger surface area exposed to the soil.

Square Shaft piers

Work best in tension applications, like wall anchors, soil nails or tie backs. However when installed under a building (in compression applications) the square shaft has warped and bent under the pressure. This is due to the socket and pin coupling which increases variances from straightness and can increase the potential of buckling.

Shaft-to-shaft coupling is very difficult to achieve within the upset couplings of the square shaft since the load is then transferred through double sheer of the single coupling bolt.

Concrete Piles

The concrete piles are either pre-cast then driven into the ground, or cast-in-place. For cast-in-place concrete pillars a cylindrical shell is driven into the ground then filled with concrete.

There are considerations to take into account when using concrete piles: the force of driving can cause cracks and other problems in the surrounding structures, heavy machinery is required for installation which can create logistical challenges, and cast-in-place concrete pillars need time to harden and dry.

In certain applications concrete piles can be appropriate however the installation and side effects can be detrimental to surrounding structures. Because of these potential problems, we only use helical and resistance piers.


Wall Anchors

Foundation Wall AnchorsA square shaft is used for helical wall anchors which are installed in tension applications. The anchors are designed to provide lateral stability for foundation walls. Helical wall anchors can be installed in limited access areas without the use of heavy machinery, and installation doesn't generate spoils.


Mudjacking

Also called slab-jacking, is one of the methods used to stabilize a building's foundation. Holes are drilled into the slab or under the foundation, and then concrete is pumped under the foundation. The theory is that the concrete will eliminate settlement problems.

While this method can stabilize a foundation and even lift the building to its original position, it's flawed. Without extending the stabilization solution all the way to the bedrock, there's a likelihood that the building will begin to settle and shift again. However, mudjacking in conjunction with piering can offer a long-term solution to settlement and other foundation problems.


Need Foundation Underpinning? Free Foundation, Crawl Space or Basement Inspection

If you're not sure of the source of your foundation problem, give us a call at 866-370-4816, and schedule a free inspection. We'll find out the cause of the problem and help you find the perfect solution.

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"I would like to praise your engineer and the construction crew for their professional approach to solving our foundation problems. In over forty years of practice in architecture, I have seldom seen such a well coordinated demolition/construction process. I would have JES back for any future foundation problems and will recommend JES to my clients and friends who need your services."

~ William M., Yorktown, VA

 
"The crew was wonderful especially the Foreman. We asked lots of questions and kept checking in and looking at the work. Each time we went to the basement, they stopped the work and carefully explained the process to us in a very friendly manner. We liked this crew and the foreman very much."

~ Suzzanne B., Culpeper, VA