Rail Container Loading and Storage Area

The pavement section installation for the container storage area was underway. It was designed with two layers of a composite biaxial geogrid and geotextile fabric, with 12” ALDOT 825B aggregate placed on the bottom layer and 6” on the top layer. During construction, significant rutting and subgrade pumping occurred after installation of the first layer of geogrid and stone. There was significant risk in continuing to build the pavement section as designed due to the soft, unpredictable, and undocumented subgrade material. This material included coal outcroppings, wood debris, old timber pilings and brick structures. Also buried at the site was an abandoned storm drain pipe that continued to add water to the subgrade.

A Tensar representative evaluated the site conditions. Using Tensar+ design software, the representative designed a solution using NX850-FG to minimize cut and fill while also providing the separation benefits of a non-woven fabric. The design recommendation required a single 18” lift of coarse sand with low fines content to be placed on the NX850-FG. The original pavement section was then installed above the newly stabilized subgrade.