The Challenge

AquaGuard Foundation Solutions were approached by a Commercial Company to assist them with resolving concerns in their Warehouse. The company moved into the warehouse premises in January 2016, and after 6 months of being in the building, they started noticing cracks on the interior block walls, a sizable crack in the concrete floor plus there were a myriad of small cracks in the dry-wall. They watched the problem cracks get bigger over a two-year period, hoping that it was going to stop. 

The AquaGuard Team conducted a diagnosis knowing that the symptoms all pointed towards a foundation issue. It was quickly determined that the left side of the building had sunk about 5 inches over a period-of-time. In fact, the entire left side of the Warehouse floor was not only sinking, but it was sliding at the same time. 

Foundation problems don’t remedy themselves. Normal settlement can happen, but anytime you have settlement of a half-inch and more,  it points towards a major problem. The company would remedy the cracks in the Foundation Walls with some caulking but then over the next two or three months, the cracks would start to open up again. The sinking was not stopping. 

The floor cracks started getting wider, namely, the expansion joints that were in the concrete floor to allow for movement of the slab started out at a half-inch wide but grew to an inch and wider over this two-year time frame.  

Initially, it was not clear as to why there was a problem. One of the concerns was perhaps the soil was poorly compacted when the building was erected, or perhaps the warehouse had been built over a trash pit, which would explain the voids in the soil under the building. 

This is a multi-million-dollar facility, who reached out to their insurance company for financial assistance, but to no avail. Generally, the Insurance Companies will not insure foundation problems or water intrusion issues. As far as they are concerned, these events are ‘an act of God’ and out of their jurisdiction. 

The storm-drainage system for the warehouse runs along the left side of the building, 150-feet of linear pipe, with two large 8-foot diameter retention pipes. Further investigation required we dig up the ground and examine the length of the pipes. Our qualified team noticed that the joints on the pipe, which were interspersed every 30-feet, were not sealed.  The sealant which had been applied was now peeling away resulting in water leakage and seepage into the surrounding soil bed. 

Any structural integrity that the soil had at the time of construction, was fast fading. We have confirmed that the Inspector did pass the buildings soil compaction test during construction.  

But, unfortunately, over time the water seeping out of the joints on the retention pipe, have now created something of a swampy, mosh-pit under and alongside the warehouse. 

The Solution

The first concern is to underpin the building and stabilize the foundation. We excavated the entire length and breadth of the periphery of the building and installed Push-Piers. 

Here’s the rub. The soil is in such poor condition and does not have the compaction required to hold the steel pipe of the Push-Piers in place, keeping each pier in a straight line all the way down to bedrock, which is how far down the team have drilled. 

As a result of this extremely poor soil compaction, we need to install Helical Piers in between each Push-Pier. The helical shapes will give the pier stability as we gently and slowly apply more and more pressure. 

Once we get the building stabilized, and we know the structure is not going to sink any further, we will then go ahead and deal with the retention pipe. 

The solution for is for our team to inject PolyLEVEL on the interior rims at each of the 30-foot lengths joins on the retention pipes.

We will also go inside the building and use PolyLEVEL on the slab itself to stabilize the soil below and to prevent further settlement, as well as to attempt to lift.  

Products Used: 

This is a multi-faceted issue hence the solution is more than only Push-Piers, it is inclusive of Helical Piers and PolyLEVEL to seal the pipe and level concrete slabs inside the building. (How to level sinking concrete.)