Project Name: DP World Port Container Yard
Project Location: Dakar, Senegal, West Africa
Sites underlain by soft cohesive or loose mixed soils often require some form of ground improvement, primarily to reduce total and differential settlements to be viable for development and to meet long-term serviceability requirements. For many projects, this means implementing a pre-loading strategy (aka – surcharge loading) to accelerate soil settlement and improve subgrade characteristics. Unfortunately, this strategy often comes at a great cost to both the project budget and schedule. It can take several months (in some cases years) to implement and often requires the placement of tens of thousands of cubic meters of imported fill material, only to have to remove this material at the end of the pre-loading period. For the DP World Container Yard project, pre-loading was not an acceptable option to overcome challenging site conditions.
To enable operations by gantry cranes, the shallow ground improvement was necessary to stabilize soft subgrade conditions across a 25,000-square-meter-area at the new DP World Container Yard at the Port of Dakar. The port terminal required base-layer and surface stabilization, but overall project cost and timing were major considerations. The GEOWEB® Load Support System met these requirements by offering fast installation and a reduced cross-section. More importantly, the GEOWEB system eliminated the need to pre-load the installation area, which would have delayed project construction for a full year. The GEOWEB system also allowed for beneficial reuse of recycled on-site fill material, thereby eliminating offsite disposal costs along with the need to haul in expensive crushed aggregate fill. The section was topped with interlocked paving blocks as the final wear surface over the completed GEOWEB system. The first 10,000-square-meter area of the container yard was successfully installed just before the rainy season and has been in regular use with no settlement or maintenance needed, even with exceptionally heavy rain and flooding events.
The time, cost, and carbon footprint savings resulted in a successful project and a satisfied client. The time, cost, and carbon footprint savings resulted in a successful project and a satisfied client.
Virtual Support and Technical Resources to Overcome COVID-19 Construction Challenges
Shafa Construction West Africa was the main contractor for the design-build project, and this was their first time installing the GEOWEB® Load Support System. Due to COVID-19 travel restrictions, virtual support took the place of traditional on-site support. Shafa utilized Presto Geosystems’ vast library of webinars, videos, and installation guides, and they also connected virtually with the Presto technical team and local agent PSM Technologies. The installation went smoothly, and Shafa found GEOWEB installation was faster and easier than traditional shallow ground improvement methods.
Long-Lasting Components and Accessories Designed for Performance
The patented ATRA® Key connection device allowed for fast, permanent, and corrosion-free connections for the individual geocell sections. The GEOWEB® system´s industry-leading seam strength for geocellular confinement technology provided load support for the heavy gantry crane and stacked containers with just a single layer of geocells while eliminating the need for a cement-bound layer or any additional geotextiles.