NAPA Auto Parts Foundation & Slab Repair

Thursday, May 11th, 2017 by Niles Erickson

Challenge

The lot for this NAPA Auto Parts warehouse, and neighboring businesses, was completely man made and built from fill brought in from other locations. Towards the back of the lot there is a 60 ft to 70 ft drop, which shows just how much fill was brought in to provide a level surface for this lot. What the property owners are now facing is foundation settlement, which is common in lots where there is a substantial amount of fill underneath the foundations. Fill is subject to settling if there are large amounts of biodegradable materials, such as dead trees or stumps, mixed in with it. There is also a good chance of fill settling if it is not properly compacted and prepared prior to the heavy structures above being built or installed.

This NAPA Auto Parts warehouse is 100ft long and 50 ft wide. The foundation of the warehouse was cracking all over due to settling soils underneath the structure. There were signs of cracking on the interior warehouse floor, which was a concrete slab. Upon excavating down on the outside, large cracks were found in the foundation walls as well. It was also clear to see the settling by just looking at the building, as the roof was gradually getting lower in parts, weakening the integrity of the overall structure.

It would take a variety of foundation repair products and methods in order to stabilize the buildings foundation.

Solution

The first step was to install GeoLock Anchors into the foundation walls. These were installed from the outside of the foundation by drilling into the walls and inserting the anchors into the soils on the other side. The purpose of these wall anchors was to prevent the walls from buckling and sliding off each other due to the long, horizontal cracks in the foundation walls.

With the GeoLock Anchors in place, the next step was to install helical piles/anchors deep into the fill soils underneath the foundation. These helical piles were drilled down into the fill at depths up to 75 ft down and securely attached to the footing of the foundation. 75 ft was required with most piles, as the fill could not support the weight of the structure, and the more dense, natural bed rock was found to be at such depths as mentioned. In order to permanently stabilize the foundation, the helical piles had to reach beyond the unstable fill soils.

With our helical anchors down into stable soils and bedrock, the warehouse building is permanently stabilized and will no longer settle.

The final step is to use PolyLEVEL on the interior of the warehouse in order to relevel the floor. The concrete floor was cracked and sinking more and more down towards the rear of the building. PolyLEVEL was used to lift the slab and stabilize it, providing a safe working environment for this NAPA Auto Parts location.