The Port of Savannah's Mason Mega Rail Project is a 185-acre intermodal facility that comprises 18 tracks for simultaneous operations of six 10,000-foot-long trains. Upon completion, it will be the largest on-dock rail facility for a port authority in North America which will help boost the Garden City Terminal's (GCT) rail capacity to one million container lifts per year. A majority of the Mason Mega Rail site was an unregulated industrial landfill over low-lying land along a major drainage canal. The banks of the canal are underlain by very soft and compressible soils. The new rails were laid over the landfill, and two new rail bridges were constructed to cross the canal. The landfill debris and the soft marine deposits present major challenges to ground stability and settlements.
The following six ground improvement techniques were employed to treat the landfill material and mitigate the settlement and stability concerns: dynamic compaction of the landfill, undercut and geogrid stabilization for wetlands, driven prestressed concrete piles for rail-mounted gantry (RMG) cranes and two rail bridges, rigid inclusions for embankment stability, surcharge with wick drains for drainage structures with high fill, geocell MSE walls along the edge of the rail yard. These innovative measures saved about $12 million over the conventional approaches. This presentation outlines the project design process, subsurface conditions and associated challenges, geotechnical considerations of various ground improvement options, and experience and lessons gained from their applications of the ground improvement technologies.
Please feel free to contact Guoming Lin of Terracon at Guoming.Lin@terracon.com for additional questions.
The online version of the article can be found here.