Yearly Archives: 2022

Understanding Hoop Stress in Geocells

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 »

Building Climate-Resilient Infrastructure Using Geosynthetics

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 »

Meet the Presto Geosystems Team: Get to Know Bryan

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 »

Are material shortages delaying your road construction projects? Here is how to stay on schedule and within budget.

Written by: Bryan Wedin, P.E., Chief Design Engineer Road construction is booming, and this trend is expected to remain strong due to high demand and the Infrastructure Investment and Jobs Act (IIJA), which includes investments across many sectors, including public infrastructure. Along with this boom, the road construction industry has been dealing with inflation-related cost increases and limited availability of construction materials. The industry has been impacted by supply-chain interruptions and shortages for many roadway materials including lime, cement, and even aggregate. These materials are typically used for roadway base construction, which means road construction projects that use these materials may be subject to delays. Due to these shortages and delays, on-site material or sand-filled GEOWEB® geocells can provide a cost-effective, readily available substitute for base materials–especially where native subgrade conditions consist of weak or soft soils. GEOWEB® Geocells for Roadway Base Stabilization The GEOWEB geocells have been used for load support and foundation applications worldwide for more than 40 years. Developed in collaboration with the U.S. Army Corps of Engineers (USACE) in the late 1970s, Presto co-invented the technology now known as geocells or a cellular confinement system (CCS). The early applications of geocells consisted primarily of stabilized, expedient… Read more »

Presto Geosystems Announces Launch of the ATRA® Wall Key

We are thrilled to announce our newest innovation at Presto Geosystems: the ATRA® Wall Key (patent pending) for the GEOWEB® Retaining Wall System. The ATRA Wall Key is used to connect adjacent GEOWEB Retaining Wall sections through the GEOWEB material slots (I-slots). The ATRA Wall Key includes an integrated washer at the base of the handle for coverage of the I-slots when connecting adjacent wall sections, frictional barbs for an improved interlock with the GEOWEB sections, and an ergonomic handle with S-shaped contouring for ease of installation. The ATRA Wall Keys are the most effective way to connect the GEOWEB Retaining Wall sections, ensuring the long-term success of your project. Made of non-reactive, chemically inert high-density polyethylene, the ATRA Wall Keys provide a more secure and permanent mechanical connection over staples or zip ties, and they are the only geocell connector specifically designed for use in exposed wall face applications. Formulated to withstand weathering and ultraviolet radiation, the ATRA Wall Keys will not corrode or photodegrade, even when exposed to harsh environments. Securing sections with the Wall Keys is faster than using staples or zip ties, requires no tools, and can be completed by one installer with one easy turn…. Read more »

“Or Equal” Substitutions in Geosynthetics: Evaluating the Contractor’s Proposed Alternative Amidst Global Supply Chain Disruptions & Rising Costs

Written by: Michael J. Dickey, P.E., Director of Presto Geosystems As supply chain issues and project delays continue to wreak havoc in the global geosynthetics industry, Presto Geosystems has prepared this “reboot” of our tips for evaluating “or equal” substitutions to help you navigate the decision-making process when confronted with a proposed alternative geosynthetic product. According to a recent special feature article from Geosynthetic News Alerts (GNA), more oversight and diligence is needed—now more than ever—as deceptive products and inferior raw materials continue to find their way into global markets. According to GNA “Distributors and installers that place orders in good faith—particularly with overseas vendors—may wind up with rolls of geosynthetics they can’t use, and no wriggle room in compressed delivery timelines to find alternatives or otherwise rectify errors.” To protect against this, GNA goes on to emphasize the importance of vetting geosynthetics suppliers to maintain quality metrics. In light of this, Presto offers this reboot of our five tips for evaluating “or equal” substitutions to help you keep your project on the path to success amidst the chaos. Tip #1: Review Product Datasheets Closely (Be Wary of Disclaimers) Many design professionals tend to focus on the numbers shown on… Read more »

How Geosynthetics Are Uniquely Poised to Help Alleviate Congestion at U.S. Ports

Written by: Michael J. Dickey, PE, Director and Bryan Wedin, PE, Chief Design Engineer On May 6, 2022, the Maritime Administration (MARAD) released an amended Notice of Funding Opportunity (NOFO), allocating over $234 million for port infrastructure development in 2022. Adding to the previously appropriated amount of $450 million from the Infrastructure Investment and Jobs Act (IIJA, or Bipartisan Infrastructure Law), this will bring the total amount available for port improvement projects to $684 million for FY2022. The significance of this investment comes at a crucial time. According to the American Association of Port Authorities, the pandemic has laid bare the need for a transport system that is able to surge and stretch across all links—from sea, to land, to rail, to warehouse, to consumer. The question is, how can this funding be used to meet this need quickly and cost-effectively? The answer may lie in a strategy implemented in 2021 in the state of Georgia to alleviate congestion at the Port of Savannah. The Georgia Port Authority, in partnership with Norfolk Southern, implemented a solution that has caught the attention of other U.S. port authorities and Class I railroads using what is being referred to as “pop-up container yards”…. Read more »

Dam Structure Safety Installation and Repair Using Advanced Geosynthetic Technology

Written By: Samantha Justice, P.E. Dams and Spillways Are a Critical Part of U.S. Infrastructure With estimates of 84,000 structures nationwide, dams and spillways are essential for controlling flooding, water distribution and management, and providing hydroelectric power. Unfortunately, these structures cannot last forever. The average age of dams and spillways in the US is 57 years, seven years over the typical 50-year lifespan of these structures. Aging infrastructure can lead to serious consequences if safety precautions are not taken, or measures are not implemented to address identified problems in a timely manner. The most important measure that any dam manager can apply is continual inspection and upkeep. The US Army Corps of Engineers Infrastructure Report Card rating for 2021 was a C-, and the health of dam structures was a significant part of that low rating. State and federal regulations provide a framework for the assessment and maintenance of dam and spillway structures-at a minimum yearly audit inspections that identify areas that need repair or replacement are required. Performing these repairs can help extend the lifetime of dams to help keep essential services in place without excessive cost or increased failure potential. Understanding Areas of Concern for Existing Structures The… Read more »

Sustainable Vegetated Channels = The Death of Rip Rap

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 »

Meet the Presto Geosystems Team: Get to Know JP

We have a great team here at Presto Geosystems, so we thought it would be fun to share a bit more about each member through a new blog series. For our inaugural Meet the Presto Geosystems Team blog post, we are thrilled to introduce José Pablo George—Presto Geosystem’s International Business Manager (BDM). Let’s get to know JP… How long have you been with Presto Geosystems? Time slides and blurs in a funny way. It seems so natural for me to be doing what I do with GEO, as if I’ve always been here and can draw deeply on decades of experiences, yet at the same time I still have the positive outlook and optimism of a freshly minted graduate. The year-over-year calendar and the bits of chrome in my hair suggest a compromise: this year marks my eighth year with GEO; call me a well-seasoned new-ish guy. Can you tell us a bit about your background? My specialty is in establishing, culturing, and maintaining business relationships, especially with our international clients. My former life and experiences pre-Presto support this well. I was a Spanish teacher (secondary schools and technical colleges) for 17 years, and have the linguistic skills and cross-cultural… Read more »