GEOWEB Load Support System

Project Name: Carlton Memorial Reserve

Project Location: Sarasota County, FL

The GEOWEB® Permeable Load Support System

Sarasota County, Florida acquired a 24,565-acre (9,917 hectare) environmentally sensitive wetlands parcel to build the T. Mabry Carlton, Jr. Memorial Reserve—a public use and education facility. The first phase of the project required building a 3,200 sq. ft. (300 sq. m) roadway to the building site and a parking area for 51 cars.

Bids for alternative systems submitted by local contractors were cost-prohibitive. The GEOWEB® system was ultimately specified and used as the road-building material. The project was installed with Sarasota County personnel and equipment resulting in a 45% savings.

Engineers Bishop and Associates required that the roadway and parking lot at T. Mabry Carlton, Jr. Memorial Reserve serve a dual function. The system was required to support loads over poor soils and also function as a stormwater retention system, storing the first inch of rainfall. The retention system consisted of 6-inch-deep (150 mm) GEOWEB sections and #57 stone infill. Seven inches of #57 stone with 40% voids yielded a capacity of 2.8 in (71 mm) of water storage, a 2.8 safety factor. The permeability rate of the underlying soil was 3 inches (75 mm)/hour, which resulted in the system being available for the next storm within 2.3 hours, a safety factor of 31.3.

The roadway and parking areas were built with the base approximately 8 inches (200 mm) below the natural surface to form a surface that was flush with the existing terrain. A geotextile was first placed over the muck soil as a separation and filtration layer. Next, 6-inch-deep (150 mm) GEOWEB sections were placed over the geotextile fabric and secured with stakes. The sections were stapled together, and the cells were infilled with #57 stone. Another 2 in (50 mm) of stone was placed on top of the GEOWEB system for maximum water retention, drainage, and as a surface wear course.

For speed and ease of installation, custom lengths of the 6-inch-deep (150 mm), 8-foot-wide (2.44 m) GEOWEB sections were used. Special 12-foot (3.66 m) and 24-foot (7.32 m) lengths were used for the single- and double-lane roadways, and 26-foot (7.92 m) lengths for the car parking area. Presto distributor, R.H. Moore & Associates, supervised the installation and helped Sarasota County crews significantly improve the installation rate.

The fully engineered GEOWEB system proved to be the right solution for the T. Mabry Carlton, Jr. Memorial Reserve project, offering cost-effectiveness, speed, efficiency, and environmental benefits.