Airport Slab Lifting and Void Filling

The Challenge - Settled Concrete Floor

This airport has an underground utility corridor connecting two buildings. The concrete floor in the corridor has settled in a few locations resulting in damage to the concrete where it meets the grade beams and has created a number of trip – fall hazards. The floor was also found to have a considerable void space under the slab creating instability in the concrete. The airport’s operations staff contacted a local engineering firm who conducted soils tests. The results of those tests indicated weak soils at a depth of 3’ that were the cause of the settlement and voids.


Additionally, it was discovered that at one of the construction joints in the tunnel the seals had failed and there was considerable ground water flowing into the corridor each time there was a rainstorm.

The tunnel comprises an area of some 135’ long x 6’ wide. During the project discovery phase, we found voids up to 3” deep under the slab. We also found the floor had settled by the elevators up to 1.5” over an area of 47’ X 6’. 

The Solution - Slab Lifting and Void Filling

Poly-Mor filled the void spaces and leveled the concrete slab to remove all trip hazards. We also stabilized the soil under the tunnel by injecting polyurethane through 3’ deep probes into the ground throughout the work area. A total of 22 soil stabilization injections were employed on a 6ft grid pattern to solidify the extremely weak soils. This process stabilizes all the weak soils which greatly mitigates the risk of any future settlement. 

The Result

Follow up was completed a month later and all joints remained dry and the tunnel floor has been stabilized with no additional movement. The consulting engineer reviewed the completed work and found it to be an excellent solution. 

If you are currently facing challenges related to slab settlement, leak sealing, or weak soil stabilization, we encourage you to get in touch with us at Poly-Mor. Our team of experts is ready to assess your unique situation and provide you with a free, no-obligation quotation. We take pride in delivering reliable, cost-effective solutions that exceed expectations.

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