It’s no secret that America’s infrastructure is desperately in need of investment. The American Society of Civil Engineers (ASCE) gave the country’s infrastructure an overall grade of D-plus in its 2017 Infrastructure Report Card—dangerously close to an outright failing grade. The ASCE estimates that the U.S. will need to spend nearly $4.5 trillion by 2025 to fix the country’s roads, bridges, dams, and other infrastructure. Our nation’s roads and bridges—commonly referred to as the “backbone” of the U.S. transportation system—received grades of D and C-plus, respectively. These transportation systems are deteriorating due to advancing age, increasing use, and inadequate funding. This degradation leads to a significant cost to users in terms of time, money, and safety. There are over 4 million miles of road in the United States, and the cost to maintain these roadways can vary greatly by state. Several factors determine maintenance costs, including the type of pavement surface, its current condition, its geographical location, average precipitation, number of annual freeze/thaw cycles, and frequency of use. Three-Dimensional Geocells Provide Solutions to Aging Infrastructure The long-term performance of infrastructure construction projects depends on the strength of the underlying soil. Through an interconnected honeycomb-like network, 3D geocells confine and stabilize… Read more »
Posts Tagged: GEOWEB
Every year, railroads dedicate a great deal of capital and maintenance expense towards the creation and upkeep of high quality ballast layers. Enduring well-designed ballast is quite literally the foundation on which a successful rail line operates. With ballooning rail traffic carrying heavier loads than ever, GEOWEB cellular confinement (Geocell) effectively takes the pressure off critical ballast systems. Oregon State University (OSU) recently performed state-of-the-art, three-dimensional dynamic Finite Element modeling to analyze the reinforcing benefit of GEOWEB geocells in railway applications. This study was completed in cooperation with the University of Kansas (KU) who simultaneously performed a testing program of Geocell reinforced ballast placed over weak subgrade material using HDPE GEOWEB material. The digital modeling results were reinforced by the laboratory tests and showed a significant decrease in settlement of the railway ballast when GEOWEB confinement was used. The use of GEOWEB technology not only decreased settlement, but reduced pressure on point-to-point aggregate load transfer contact which in turn resulted in less damage to ballast aggregate particles leading to less progressive deformation and longer maintenance frequencies of the entire ballast embankment. In short, more cycles means less track down-time for maintenance. The research results were clear. The benefits of applying… Read more »
Written By: Bill Handlos, PE, Director of Presto Geosystems Geocells (cellular confinement) offer a more effective and practical 3D design solution to load support challenges than multilayered 2D geogrid efforts. Geocells transfer applied loads instantaneously, delivering practical soil stabilization in a product that is fast and easy to install. How do geogrids work? Geogrids rely on rutting, displacement and lateral movement of the road material to activate the load support reaction of the product. As shown below, failure of the driving surface must occur before the geogrid reacts. As a result, rutting and soil displacement is a prerequisite reality to the system. Since the geogrid is two-dimensional, material not located directly within the plane occupied by the geogrid is free to move, shift and displace. It is essential that geogrids are placed in a flat or a pre-tensioned manner—but that is not practical in a construction environment. It is common to see geogrids unrolled over a prepared grade with an undulating surface. As aggregate is placed over the top of the geogrid, the material kinks and waves, further warping the 2D plane. The geogrid is rarely pulled tight during installation which does not allow full tension under… Read more »
Written By: Bryan Wedin P.E., Chief Design Engineer, Presto Geosystems Not all geocells are created equal. While most manufacturers can provide similar-looking written specifications, you need assurances that the material delivered for your project is of the high quality that you expect. Important factors in the success of your geocell project include: Quality The geocell material is proven, strong, and will last Require only the highest quality virgin High Density Polyethylene (HDPE) resin Low quality or recycled resin can lead to weak and/or inconsistent seam strength, putting the success of your project at risk. Non-HDPE materials cannot match the nearly 40 years of in-ground experience of HDPE geocells and plastic alloy proprietary blends can mask cheap stiff filler materials. ISO Certification Important, but the manufacturer sets the testing protocol for the certification. Require a Certificate of Analysis (COA) for the material that is shipped to your project. An ISO certification that does not require continuous testing is lacking. Integral Components The complete solution includes proper components Non-corrosive, high-strength panel connection method (ATRA® Keys vs. weak staples or zip ties) Anchors that provide secure connections to the geocell (ATRA® stakes vs. J-hooks) Load Transfer Devices for tendon applications that are non-corrosive and… Read more »
Written by William G Handlos, P.E. Product differentiation is often thought of as a way to create a competitive advantage. Typically, a company decides to focus and promote upon a certain attribute(s) of a product making this attribute a key feature of their value proposition statement. For example, a major automobile company might focus and promote a rear lift gate automatic opener actuated by the movement of the driver’s foot under the rear bumper. This inexpensive addition to an SUV’s feature set may be the difference in a buying decision between competing automobile brands, particularly in a market with fierce competition and similar option sets. In this case, the manufacturer has created a product differentiator that truly adds benefit to the customer. Presto Geosystems® developed the original geocell in the late 1970s and GEOWEB® Geocell product enhancements have been developed every few years, always with the intent of offering benefits to their customers with each refinement. For manufacturers who sell to contractors who bid on projects that are based upon engineered plans and specifications, the waters can be murkier. Is product differentiation created for the benefit of the customer or is differentiation simply crafted to create a unique set of… Read more »
Written by William G. Handlos, P.E.
Written by William G. Handlos, P.E. In the past, salesmen were hunters who would pursue customers with cold calls, emails and office visits to help them understand how problems could be solved with product line offerings. They would qualify opportunities, perform a needs analysis and pitch their value proposition to the identified decision maker. After the pitch, a price proposal would be made and if the solution was perceived a fit – negotiations would ensue and the job would be won or lost. The salesman controlled the buying process. If you haven’t noticed, there is a significant shift occurring in the sales process. Now, the customer does internet research and is well into the decision process before we even get the chance to meet them. Information that they find on websites, blogs, digital industry trade publications, and discussion boards about the products we offer supplies them content they use to form opinions and make decisions to either contact you….or to move on and continue their search,… perhaps with a competitor. The graphic below from Inboundsales.net says it all. We all have at our disposal – a matchmaking service called Google® (and others) that connect us in mere seconds. As a… Read more »
Written by: William G. Handlos, P.E. How long does it take to install? It is a question we hear every day. When it comes to cost and installation rates for geosynthetic construction products, there are no simple answers to what seems like simple questions. In fact, beware of those who try to simplify determination of installation costs for their products with quick answers or charts and tables to determine construction rates. Experienced project managers and site supervisors of the crews charged with installation are in the best position to estimate productivity rates. They know best their crew’s capability and the characteristics of the site involved. The variables that need to be considered include: Crew size, talent, work ethic and workday length Temperature, precipitation and length of day (sunlight) Experience with product class Size of the project Site Access Site Conditions (see weather) Crew The optimum crew size is important. Too small and you may lose the benefits of assembly line productivity. Too large and you will find that you fall over each other and pay for extra “inspectors”. All crews are not created equally. The familiarity with tools and techniques vary greatly as does the work ethic both between crews and… Read more »
Written by William G. Handlos, P.E.
Written by William G. Handlos, P.E. Highway Stormwater Control: Porous Vegetated Drivable Road Shoulders Gravel road shoulders are not porous. Rainwater sheet flowing off highway pavement passes right across the aggregate shoulder carrying with it sediment and other pollutants that ultimately end up in freshwater creeks and rivers. Aside from pollutant loading, re-grading shoulders is a continuous activity for State and County crews to repair eroded sections after several rain events. Some counties have taken a smart solution approach to this problem and are using geocell cellular confinement systems to reduce maintenance costs and to improve water quality. Shown below are the cross sections detailing a GEOWEB® geocellular drivable vegetated shoulder solution. The infill to the geocell is made up of 2/3rd clear stone aggregate (void ratio 30 – 40%) and 1/3rd topsoil. The topsoil remains uncompressed within the interstitial spaces between the stone, and the stone is the structural component that carries the load. The topsoil allows for the vegetation roots to grow and feed upon the nutrients and water in the topsoil. This system percolates runoff from the highway while offering proper load support for vehicles that pull off the side of the road. The GEOWEB® cells confine the… Read more »