Cul-de-sac Soil Stabilization in Tega Cay, SC

The Challenge

Soil instability and settlement of cul-de-sac slabs.

A cul-de-sac located at the top of a steep embankment in Tega Cay, South Carolina, was experiencing significant settlement along its slope. Positioned at the end of a sloped roadway, the cul-de-sac had developed cracks and visible signs of instability, with roughly 3 inches of slab settlement. Stormwater runoff during heavy rain events accelerated erosion beneath the pavement, washing out supporting soils and leading to repeated infrastructure failure—this being the second repair attempt in five years.

Key Facts

The Solution

Soil stabilization with polyurethane.

After a geotechnical engineer conducted bore testing that revealed extremely weak soil conditions at a depth of 20 feet, the city contracted Groundworks to perform soil stabilization using geotechnical polyurethane. Injections began at the deepest depth and progressed upward in 5-foot increments, ensuring proper soil densification and long-term stability. The entire project was completed in one day, minimizing disruption to the community.

The Impact

A long-term solution for soil erosion and slab settlement.

Approximately 2 inches of lift were achieved across the affected zone, with the final inch left for future surface milling and overlay. Around 2,000 square feet of pavement were stabilized. The project provided a long-term solution to recurring erosion and settlement issues, reducing the city’s risk of future structural failure and eliminating the need for repeated reconstruction. From initial engineering evaluation to completed installation, the project timeline was just two weeks.