C+S May 2022 Vol. 8 Issue 5 (web)

Presto Geosystems | www.prestogeo.com


Designing Resilient Port & Intermodal Yards with Geosynthetics

According to a recent report, United States ports handled a record 50.5 million shipping containers in 2021—an in- crease in total container volume of 16 percent. Unprecedented demand for goods contributed to this staggering figure, and projections for 2022 do not indicate that demand will decrease anytime soon. Ports and intermodal yards are a vital link in the nation’s supply chain, and disruptions can cause an undesirable and costly ripple effect. Because ports are susceptible to a variety of interruptions, it is imperative to design resilient port infrastructure to support the increased container volume. Ports and intermodal yards in coastal areas are more prone to pavement problems due to inherent soft, unsupportive soils and high water levels. Soft subgrade conditions combined with heavy traffic loads from trucks, reach stackers, and gantry cranes can accelerate the degradation of paved or unpaved surfaces and subbase materials. This results in differential settlement, ruts, potholes, and an overall reduction in pavement service life. Moreover, these issues require continual, costly maintenance, and can result in interruptions to facility operations. Repair efforts typically focus on grading, patching, or resurfacing, but the problem is not at the surface—it is a base stabilization problem. Strengthening Base Materials Using GEOWEB® Geocells Creating a resilient pavement structure capable of withstanding long-term, heavy-duty traffic demands starts with stabilizing the base materials. The GEOWEB® Soil Stabilization System was invented specifically for this purpose. Cre- ated through a collaboration between the U.S. Army Corps of Engineers (USACE) and Presto Products Co., GEOWEB® was designed to address the needs of the U.S. military to build sand access roads capable of supporting heavy vehicle loads over soft or unstable soils. The system’s deep cellular network controls both the horizontal and vertical movement of unstable base soils. In load-support applications, when a static or dynamic load is applied to a geocell-reinforced layer, lateral earth pressures are mobilized and transferred across a three-dimensional network of interconnected cells. The layer essentially performs like a composite material, facilitating a phenomenon known as the mattress effect. Reduce Construction Costs, Emissions with GEOWEB® Geocells With geocells, it is not uncommon to see an overall reduction in the required thickness of the base layer in a load sup- port application by 50 percent or more, along with an overall improvement in allowable bearing capacity. This applies to both unpaved and paved surfaces at port and intermodal yards, including container stacking yards, access roads, and chassis storage areas. This results in a reduction in upfront construction costs, and it provides long-term savings resulting from reduced maintenance and repair costs, along with fewer interruptions to facility operations.

Moreover, in many cases, geocells allow for the beneficial reuse of on-site materials, eliminating the need to purchase expen- sive aggregate or imported structural fill. Compared to planar geosynthetic products such as geogrids—which commonly rely on expensive, imported high-quality ag- gregate—geocells are highly versatile and can be filled with a variety of commonly- available and economical infill options. Infill options include sand, crushed aggregate, re- cycled concrete, pulverized debris, recycled asphalt, or other locally sourced materials. These advantages not only offer the poten- tial for savings in terms of upfront construc- tion costs and long-term operational costs,



May 2022

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