- Forensic evaluation
- Geotechnical investigation
- Hydrologic and hydraulic modeling
- Site drainage design
- Groundwater evaluations
- Construction documents
- Environmental permitting support
- Resident engineering
- Construction administration services
The Thornton Justice Center is comprised of multiple facilities including a municipal court building, police building, bi-level concrete parking structure, asphalt parking areas, concrete sidewalks, landscaped areas, utilities, and retaining walls.
Following construction in 2005, the facilities have required ongoing maintenance to address damage and distress caused by expansive soil and bedrock material in the foundation.
RJH was retained by the City of Thornton (Thornton) to perform a comprehensive investigation program to evaluate the expansive soils, settlement, and drainage issues. RJH performed site visits to inspect the foundation and implemented a detailed survey around the Justice Center to document areas with excessive differential movement, poor drainage, seepage, and building damage. A laboratory testing program was also implemented to evaluate swell potential of the expansive soils and bedrock.
RJH concluded that the foundation materials have significant potential to expand when wetted and that the materials would continue to expand when exposed to additional moisture. The foundation materials were being exposed to moisture because of inadequate surface drainage, cracks in the pavement, high groundwater levels, and a deficient existing drainage system. Damages to facilities from the expansive foundation resulted in even more moisture exposure to the subgrade thereby creating a “snowball effect” that likely would have led to significant structural damage and loss of building serviceability.
Based on the results of the investigation program, RJH developed concept and final designs to mitigate issues caused by the expansive foundation materials. The selected concept included installing a groundwater collection trench to mitigate high groundwater levels, an impermeable geomembrane apron with overlying drain pipe around the perimeter of the buildings to reduce infiltration, and site grading and retaining walls to convey surface water away from the buildings.