Written By: Cory Schneider, Environmental Scientist, Presto Geosystems Natural resources are finite, or at a minimum, can easily be consumed faster than they can be replaced. As such, the conservation of natural resources is a pragmatic endeavor. Geosynthetics—widely available materials used in construction, civil engineering, and environmental protection—can be useful in promoting the conservation of these resources. When used as intended, geosynthetics can enhance soil properties and reduce the demands placed on natural resources. Types of Geosynthetics Geosynthetics are typically made from synthetic polymers, such as polyethylene, polypropylene, and/or polyester, and are designed to be durable and resistant to weathering and other environmental factors. General groupings of geosynthetics include: geotextiles, geogrids, geomembranes, geocells, erosion control blankets (ECBs), and turf reinforcement mats (TRMs). Geotextiles (permeable) and geomembranes (impermeable) provide separation, while geogrids and geocells provide varying degrees of stabilization and confinement. ECBs and TRMs, made with a combination of natural and synthetic fibers, resist surficial erosion by preventing seed washout prior to germination. Application areas where these geosynthetic materials are used typically include: load support, slope, shoreline, and channel protection, and earth retention. Using Geosynthetics in Load Support Applications to Conserve Natural Resources In load support applications, geogrids, geotextiles, and geocells… Read more »

Written By: Michael J. Dickey, P.E., Samantha Justice, P.E., Bryan Wedin, P.E. When constructing roadways over soft soils and weak subgrades, geocells are one of the most powerful value engineering tools available to the civil engineering and construction industries today. Understandably, some engineers may be apprehensive about using a geosynthetic product for which they have an incomplete technical understanding. So, if you’ve ever wondered how geocells work in load support applications – and the relationship between lateral confinement and hoop stress – you’ve come to the right place. Generally speaking, geocells can be used to alter the geometry of a soil pressure bulb beneath an applied load through a phenomenon known as the mattress effect. Key to the mattress effect is a physical mechanism unique to geocells known as lateral confinement. When a load is applied to a geocell-reinforced layer, lateral earth pressures develop within the infill material, which is confined laterally by the cell walls against movement, in turn developing upward shear resistance along wall interfaces throughout the interconnected network of cells. In essence, lateral confinement converts horizontal earth pressures into upward resisting shear forces.     When combined with suitable base reinforcement (i.e., an enhanced woven geotextile), it… Read more »

When extreme weather events occur, communities are often left to grapple with the devastating effects. An increase in extreme weather patterns, coupled with aging or inadequate infrastructure, amplifies the often dangerous and costly damage that ensues—especially for vulnerable communities living in low-lying areas. According to a recent study, the United States could see a 26.4% increase in flood risk by 2050, which could cause significant damage to existing infrastructure. For this reason, it is vital to build resilience into infrastructure projects to mitigate climate risk and ensure the long-term reliability of critical infrastructure. Incorporating geosynthetics into infrastructure can improve the ability of communities to withstand and recover from extreme weather events. For example, in hurricane-prone parts of the country, designing robust access roads along power transmission lines allows repair crews to safely and quickly restore power to communities that might otherwise be without electricity for days or even weeks. Geosynthetic products, such as geocells, can be used to construct reliable access roads along transmission infrastructure, which often traverse very remote areas with difficult terrain and very soft ground conditions. Through an interconnected honeycomb-like network, geocells confine and stabilize soils that would otherwise be unstable under loading. When used in load support, slope stabilization,… Read more »

How long have you been with Presto Geosystems? Time flies when you are having fun! I have been with Presto Geosystems going on 14 years. In that time, I got to work with some really great people and enjoyed speaking with Gary Bach on how geocells were invented back in the late 70s and early 80s. Can you tell us a bit about your background? I grew up in the Upper Peninsula of Michigan and enjoyed doing all things outdoors. My father was an Olympic ski jumper, so I had no choice but to strap on a pair of skis and follow in his footsteps. I became pretty good and was in three junior Olympics before a bad fall ended that part of my life. I grew up before video games, so we were always outside playing football, baseball or just riding bikes. After a year at Michigan State University, I attended college at Michigan Tech University in Houghton, MI and graduated with a degree in Environmental Engineering. After graduation, I moved to Green Bay, WI, and worked for Foth & Van Dyke and then Robert E. Lee engineering consulting firms before joining Presto Geosystems. What attracted you to the… Read more »

Rip rap is a common channel protection method because of its resistance to most flows with appropriate rock size; however, it does have significant drawbacks. Material can be expensive, not locally available, and placement requires heavy equipment. Additionally, rip rap channels are prone to regular maintenance, collection of debris and garbage, erosion at boundaries, undermining, and movement. Naturally vegetated channels are grassed greenways that offer substantially lower maintenance and cost but are limited in their ability to resist moderate-high flows and shear forces even for short durations—unless the soils and vegetation can be stabilized. High-Performing Vegetated Solution The GEOWEB® Soil Confinement System offers protection to channels with continuous low flows—as well as moderate-to-high flow intermittent channels. The system’s honeycomb-like network creates check-dams that protect the soil layer from hydrological erosive forces and resulting erosion that impacts unconfined soils. Cell wall perforations lock up with the vegetative root for further stabilization. The GEOWEB single-layer vegetated channels can withstand ~9 ft/s (2.7 m/s), more than doubling the resistance of typical unsupported vegetated channels (4 ft/s (1.2 m/s). The GEOWEB channels can withstand even higher velocities—as high as 30 ft/s (9m/s)—with an overlying Turf Reinforcement Mat (TRM) when fully vegetated. This is a significant… Read more »