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 »
Posts By: Katie Bocskor
GEOWEB® Geocell Reinforcement Improves Structural Performance of Railway Track Beds
Every year, railroads dedicate a great deal of capital and resources toward creating and maintaining high-quality track profiles. Providing a well-designed track profile is the foundation on which a successful rail line operates. With ballooning rail traffic carrying heavier loads than ever and increased occurrence of extreme weather events, a stable track profile is essential for successful operation. GEOWEB® geocells have been used in the track bed for rail applications worldwide for more than 40 years. Through an interconnected honeycomb-like network, the HDPE-based GEOWEB Soil Stabilization System provides apparent cohesion and strength to materials that would otherwise be unstable over soft subgrades. Geocells stabilize the ballast, reduce vertical and lateral stresses, and limit ballast movement. Stabilization within the geocell system provides a longer lasting track profile that extends rail service life, while also reducing maintenance cycles and recurring maintenance costs. Research has shown that geocells reduce settlement of the ballast foundation and can reduce required cross-section thicknesses by up to 50%. This is particularly advantageous where track beds must be constructed over soft soils. The reduction in thickness leads to cost savings, along with an accompanying reduction in carbon emissions due to decreases in aggregate processing, transportation, handling, and installation…. Read more »
Protecting Environmental Geomembrane Covers With Suspended GEOWEB Geocells
Economic pressure, the desire for green solutions, and the intensification of climate extremes have converged to create a need for better methods to effect soil stabilization. Fortunately, a proven technology exists that addresses issues associated with these conditions and provides a more stable cover solution for landfill covers, lagoons, stormwater containment basins, and other geomembrane-covered systems. Soil, aggregate, and concrete protective covers over geomembranes can be secured against known gravitational, hydrodynamic, and seismic forces using the GEOWEB® Soil Confinement System. Soil and aggregate are commonly used as a protective cover over liners on slopes of 3H:1V or less. However, when slope gradients are greater, unconfined soil and aggregate covers are typically unstable and not used. In arid areas, cover depth may range from 75 mm (3 in) to 150 mm (6 in). Where conditions support vegetation, cover depth may range from 100 (4) to 600 mm (24 in) or greater where the final depth is a function of the characteristics of the desired vegetation. Regardless of cover depth, if an extreme rainfall event occurs that is 10%, or greater than what would typically be expected, soil mass increases, assumed friction angles decrease, and factors of safety for soil stability drop to… Read more »
GEOBLOCK Grass Pavers: Fire Lane Access System
GEOBLOCK® POROUS PAVEMENT SYSTEM Environmental regulations that control and limit stormwater runoff, reduce impervious surfaces, and increase green space have resulted in the growth of permeable pavements for traffic areas. The GEOBLOCK Porous Pavement System offers support for all vehicular loadings and protects the grass from the damaging effects of traffic while allowing natural groundwater replenishment. Examples of the GEOBLOCK system providing solutions for fire access lane requirements are illustrated in this case study summaries below. Test 1: The City of Kentwood (1994) Kentwood, Michigan GEOBLOCK System Put to the Test The City of Kentwood, Michigan put the GEOBLOCK system through a worst-case scenario field test to measure performance and prove the system’s capabilities. Prior to testing, a series of less-than-ideal installation conditions were established: Five inches of sand subbase was installed, developing a base support capacity of only 2.8% CBR. GEOBLOCK units were laid parallel (rather than perpendicular) to the direction of traffic. Edge restraints, typically used to help prevent block shifting until vegetation, were omitted—both of which help anchor the system. The test area was not proof-rolled prior to load applications. The fire marshal directed a 60,000 lb (22,400 kg) ladder/pumper to drive onto the unfilled 13 ft… Read more »
GEOWEB Geocells Combined with a Turf Reinforcement Mat (TRM)
GEOWEB® System – Research Synopsis Research Objective Measure the performance of the GEOWEB (GW) material combined with a turf reinforcement mat (TRM) (integrated system) with topsoil infill and vegetation under varying shear stresses and flow rates to quantify both hydraulic forces and corresponding soil loss. The test consisted of a series of continuous one-hour flows over the GW-TRM system at incrementally increasing discharges. The performance threshold was defined as the point at which 0.5 inches (13 mm) of soil loss occurred. Research Scenario The Research Facility Steep-Gradient Overtopping Facility (SGOF) at the Hydraulics Laboratory of the Engineering Research Center (ERCD) at Colorado State University (CSU), Ft. Collins, Colorado Test Timeframe April 2005-August 2006 Test Materials GEOWEB Soil Stabilization System North American Green C350 Turf Reinforcement Mat Scope of Test Hydraulic performance testing was conducted on an integrated system comprising the GW30V textured/perforated GEOWEB System and the North American Green C350 composite turf reinforcement mat. The C350 TRM was chosen for its known performance in the test apparatus. Six tests were conducted under the research program to measure the performance of the integrated system, identify stability threshold conditions, and quantify both hydraulic forces and soil loss. Assembling the Test Components The… Read more »
Designing Sustainable Ports & Yards with 3D Geocells
Stabilization for Higher-Performing Pavements Ports and intermodal yards in coastal areas are more prone to pavement problems due to inherent soft, unsupportive soils and high water levels. Heavy traffic patterns and the constant weight of loaded parked trailers and stacked containers at these facilities can accelerate the degradation of the paved or unpaved surfaces and subbase materials. The repeated pressure over poor soil conditions results in settlement, ruts, potholes, and even pavement failure. These surface problems require continual, costly maintenance and interruptions to facility operations. But the problem isn’t at the surface—it’s a base stabilization problem. Transforming Base Materials through 3D Confinement Creating and ensuring a stable surface supportive of the long-term, heavy traffic needs starts with better stabilization of the base materials. The GEOWEB® 3D Confinement System is built for this function. The system’s deep, cellular network controls both the horizontal and vertical movement of unstable base soils. When vertical loads are applied, active earth pressures in the loaded GEOWEB® cells push against passive earth pressures in adjacent cells to form a stable system. The benefits of confining fill are applied to both base reinforcement and unpaved surface applications. Permeable Unpaved Pavements Utilizing the GEOWEB® 3D system at the… Read more »
Quick Repair of Track Subgrade & Railroad Right-of-Way
GEOWEB® Geocells — Quick Fix, Long Term Protection Be prepared to repair washouts and track issues quickly and economically with one solution. The GEOWEB® 3D Soil Stabilization System is a proven 40-year solution, delivering emergency repair for track and railroad right-of-way embankments, bridges and channels. Stock readily available allows for fast deployment by local railroad crews. Contact us for more information about our GEOWEB Emergency Repair Kit Stocking Program. Wash Out Repair & Armoring: Right-of-Way Embankments | Earthen Berms | Bridge Protection | Drainage Channels Variable Infill Options: Soil/Vegetation | Aggregate | Concrete Economical Solution: Less Down Time: GEOWEB material is quickly installed to repair any size emergency and minimize track disruptions. Installation Benefit: Railroads can install the GEOWEB material with their own crews. Reduce Rock Size: Rock confined in the GEOWEB structure replaces expensive rip-rap, reducing aggregate size up to 10 times. Fast Deployment: Strong, yet light-weight GEOWEB sections are easy to transport and quick to deploy, even in difficult site access areas. Most repairs do not require large construction equipment. Construction & Repair Versatility The GEOWEB Soil Stabilization System has been successfully employed for railroad construction and repair for over 40 years. GEOWEB sections are packaged in collapsed, easy-to-handle… Read more »
FHWA Repeals its Proprietary Product Rule, Allows Geosystems’ Products to be Specified
By: William G. Handlos, P.E. Design engineers received good news on September 23, 2019, when the Federal Highway Administration repealed 23 CFR 635.411(a)-(e). Colloquially known as the “Proprietary Product Rule”, the long-standing provision made it difficult to use patented or proprietary products or technologies in federally funded projects, unless they first received a seldom-granted Public Interest Finding or classified the project as experimental. Specialty engineered and innovative systems, such as the GEOWEB® soil stabilization (geocells) lineup of products have at times been difficult to specify because there is simply nothing quite like it in the marketplace. While other geocell manufacturers exist, the Geosystems products have patented innovations making it unique in the products’ ability to perform far better than other “or equal” systems. Now, engineers will no longer be constrained to the lowest common denominator offerings from the marketplace and instead can use technically advanced materials that reduce costs, speed construction and save money. According to Federal Highway Administrator Nicole R. Nason, “This final rule promotes innovation by empowering states to choose which state-of-the-art materials, tools, and products best meet their needs for the construction and upkeep of America’s transportation infrastructure.” GEOWEB® — Most Complete Multicomponent Geocellular… Read more »
The Integration of Pervious & Impervious Pavements to Address Green Infrastructure Needs
Written by: Samantha Justice, P.E. Green infrastructure incentive programs have become commonplace for new construction and redevelopment regulations. Five of the most common incentives include: Development incentives such as expedited permitting, decreased fees, zoning upgrades, and stormwater requirement reductions. Grants. Rebates and installation financing. Awards and recognition programs. Stormwater fee discounts. A subset of green infrastructure, stormwater management usually includes the consideration of pervious/porous pavements. Traditional asphalt and concrete parking lot surfaces create significant stormwater runoff, and many municipalities do not allow them in expansion or new build situations. When the entire parking area is constructed using a porous pavement system, stormwater concerns are greatly reduced. Depending on the type chosen, pavements that return rainwater to the aquifer nearly eliminate stormwater runoff and reduce sheet flow and point load erosion problems at the pavement edges. They also reduce the need for additional stormwater infrastructure to convey the water away from the area. Integrating porous pavement systems with asphalt and concrete surfaces can reduce such failures and reduce or eliminate the need for stormwater conveyance channels, pipes, and swales. As a result, downstream stormwater pipe systems see less silt and water, which requires less maintenance and less capital expenditure for upsizing stormwater pipes…. Read more »
Are you using the right construction access mat for the job?
By: William G. Handlos, P.E. Research shows that GEOTERRA® and GEOTERRA® GTO structural mats provide a ground-surface reinforcement layer to support heavy loads over soft subgrades. More cost-effective than other reinforcement mat systems, the GEOTERRA mats can be used for temporary or permanent applications and are reusable. Offering high crush and flexural strength, the GEOTERRA mats have demonstrated the ability to handle the forces from some of the heaviest wheeled and tracked vehicles under severe conditions. Scope of Test: The University of Kansas Geotechnical Laboratory tested the performance of the GEOTERRA and GEOTERRA mat systems over weak to intermediate subgrades with CBR values ranging from 1% to 4%. They conducted a total of 12 tests to identify threshold and limit conditions, create a data-set for modeling, and determine the equivalent crushed aggregate base. Testing Procedure: Test sections were subjected to 40 kN (9 kip) cyclic loading on a 300 mm (12 in) diameter plate. Earth pressure cells were placed over of the subgrade to measure vertical interface stress distribution. Loading plate displacements were measured by the displacement transducer inside the actuator. Test Observations: The following conclusions were determined for the GEOTERRA and GEOTERRA GTO Structural Mat Systems: The GEOTERRA mats provide additional… Read more »
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