Fort Myers, Florida, experienced recurring pavement settlement problems. Because of Florida’s high water table and sandy soils, for many years the Florida Department of Transportation (FLDOT) wrote off pavement settlement as a fact of life in southern Florida. However, upon closer examination, FLDOT determined much of the settlement occurred near the catch basins built along the edges of the roads. FLDOT realized the asphalt patches they used to repair settled pavement were only short-term solutions; the real problem was below the street with the storm water infrastructure.
The catch basins in question were connected to the main storm sewer lines and cross drains (which carried water across the street from other catch basins). The soils surrounding the cross drains eventually eroded away due to leaking joints and weak soil conditions. This weakened the soils surrounding the drains further which caused the roadway above to settle. FLDOT asked the question, “Is it possible to lift the road back to grade and solve our problem with underground infrastructure?” URETEK answered with a resounding, “Yes!”
To permanently solve the chronic pavement settlement in Fort Myers, FLDOT turned to the URETEK Deep Injection® (UDI) process. They asked URETEK to densify the soil around the underground infrastructure and bring the road back to grade. The URETEK crew took soil density readings before the work began and used remote cameras to locate the joints in the cross drains that needed to be sealed. Based on this data, the crew laid out an injection grid pattern.
At 14 locations along Service Road 80, a single URETEK crew sealed leaking pipe joints and densified loose soils with UDI injections. URETEK completed the multi-site project in just 11 work days. The speed of the UDI process was a key factor in the success of the project because it limited the amount of traffic disruption to a few hours per site. Soil density readings taken after injection showed a marked improvement in the load-bearing capacity of the soil. FLDOT awarded URETEK with a perfect 100/100 score on its contractor evaluation sheet.
URETEK Deep Injection® (UDI)
Widely referenced throughout our industry, UDI involves the injection of structural polymer into base and subgrade soils to increase the load bearing capacity. This is achieved by injecting the polymer through small holes drilled directly through the pavement structure to depths determined by site-specific analysis. Our URETEK 486 Star® material flows easily into voids and weak zones within the soil mass below. Through a controlled chemical reaction, the expanding polymer compacts surrounding soils and applies a controlled pressure on targeted areas of the affected pavement above. If needed, a multi-injection design plan is utilized to gently return the pavement to its original grade. The composite material quickly cures into a strong, dimensionally stable, and water-resistant geo-material, providing years of reliable service.
URETEK 486 Star®
URETEK 486 Star® polymer is a two-component, high-density, expanding thermoset polyurethane system. It was developed to be the ideal solution for under-sealing, void filling, lifting of settled pavement, stabilization and stiffening of weak soils, and for encapsulating and sealing buried infrastructure. URETEK 486 Star® is environmentally inert, non-toxic, and resists underground water erosion or weakening due to its industry-leading hydrophobic properties.