Soil Reinforcement

From Kuo-Hsin Yang, Jorge G. Zornberg and Richard J. Bathurst: This paper examines the mobilization of reinforcement tension within geosynthetic-reinforced soil (GRS) structures at working stress and at large soil strains. Fully-mobilized reinforcement tension is assumed in most current design methods for the internal stability of GRS structures. In these methods the mobilized reinforcement tensile load is assumed to be equal to mobilized horizontal soil forces computed using active earth pressure theory. However, comparison with reinforcement tension loads measured in the field has shown that this approach is conservative (excessively safe) by as much as a factor of two. This observation has prompted the current study in which stress data obtained from a numerical study and two instrumented large-scale GRS retaining walls were used to examine the relationship between mobilized reinforcement tensile load and mobilized soil shear strength. The results show that the ratio of reinforcement tensile load and mobilized soil shear strength is not constant Only when the average mobilized soil shear strength exceeds 95%, is reinforcement tensile capacity mobilized significantly. Nevertheless, less than 30% of reinforcement strength is mobilized when the average mobilized soil shear strength reaches peak soil shear capacity. These results help explain why current design methods lead to computed reinforcement loads that are very high compared to measured loads under operational conditions. Learn more here.;

With more than 100 presentations, numerous networking opportunities, and special sessions on today's hottest waste management topics, the Global Waste Management Symposium (GWMS) 2010 is a must-attend event. It will provide the forum for topics critical to the global waste community. GWMS 2010 will be held 3-6 October 2010 at the JW Marriott San Antonio Hill Country Resort and Spa in San Antonio, Texas. Learn more.

The Global Waste Management Symposium (GWMS) provides the forum for topics critical to the global waste community. The GWMS has added an important session, "Applicability of USEPA Greenhouse Gas Rules to Landfills," enabling you to learn the timely information you need to know. GWMS 2010 will be held 3-6 October 2010 at the JW Marriott San Antonio Hill Country Resort and Spa in San Antonio, Texas. The event will feature 105 educational oral and poster presentations. "Applicability of USEPA Greenhouse Gas Rules to Landfills" will be held on Monday, October 4.

The Geosynthetics Materials Association (GMA), in a formal response to the EPAs publication of a proposed rule aimed developing regulations to govern the storage of Coal Combustion Residuals (CCRs) has well supported the use of engineered geosynthetic lining systems as the most qualified measure of containment technology available today.

The Scout Moor Wind Farm is situated in Northwest England in the West Pennine Moors of Lancashire. It is the largest on-shore wind farm in England, producing enough energy (154,000 MW-h/yr) for 40,000 homes. Like many wind farms, the space and weather conditions are ideal for harvesting wind power; but access to the site and establishing firm turbine footings is a challenge. In the case of the 65MW, 26-turbine Scout Moor farm, it was constructed upon 1,347 acres (545 ha) of an extensive peat bog. Read about its stabilization with NAUE geogrids.

The utilization of geosynthetics in civil engineering and construction has long been known for saving on a number of projects, such as in the significant reduction in the need special aggregate for road subgrade. Reducing the demand for aggregate provides savings on transportation costs to a site and on site labor. It also saves on CO2 emissions from both truck traffic and aggregate harvesting and processing operations. Today, numerous geosynthetic providers are providing a number of resources for engineers, contractors, facility owners and other to help them understand how well-established and new-to-market geosynthetics meet the goals of green engineering principles of US Green Building Councils (USGBC) Leadership in Energy and Environmental Design (LEED) program.

For the construction of Idaho's largest wind farm, haul roads needed to be built. More than fifty percent of the wind farm's 100 turbines had to be completed by December, and with only a few months remaining in the year a solution was needed that would allow the construction of this project to continue, in spite of the site's unfavorable soil conditions. An unreinforced roadway with significantly thicker aggregate was considered, but that solution was considered prohibitive for time and cost. The installation of geogrid in the subgrade would allow more truck passes, without road failure and with less aggregate than the original design had mandated.

Strata Geosystems India Private Ltd today announced that their manufacturing plant at Daman producing "high-tenacity Geogrid" has been awarded the ISO 9001:2008 Quality Management System Certificate, by internationally recognized certification body "TUV-Nord." The said standard is developed by the International Organization for Standardization (ISO), an international-standard-setting body composed of representatives from various national standards organizations from 163 countries. Read more.

The 3rd International Symposium on Geosynthetic Clay Liners (GBR-C 2k10) is almost here! Germany-based SKZ, with scientific committee support from France-based Cemagref and the United States-based Geosynthetic Institute (GSI), will host the event in Würzburg, Germany 15-16 September 2010. These sessions, which will explore a vast amount of GCL applications, research, and performance, will be held at the historic Fortress Marienberg. Dr. Jorge Zornberg, president of the International Geosynthetics Society (IGS), will open the conference.

Controlling scour at storm water pipe outlets can be difficult based on the turbulent nature of the discharging storm water. Take into account the often odd-shaped outlet dimensions, and product selection and installation can be difficult. Until recently, rock was used as the main source of scour control at pipe outfalls, but rock can be limiting in that it cannot offer a vegetated design and is often difficult to maintain. North American Greens ShoreMax™ soft revetment scour protection mat was introduced recently with the intended use of providing high-performance supplemental scour protection. Learn more.

The International Geosynthetics Society (IGS) President Jorge Zornberg has sent out a message to inform IGS members that the new IGS Secretariat is Diana Davis. With her appointment comes a new address and phone number for the IGS office. Contact Diana Davis, Secretariat Manager, 605 Belvedere Rd., Suite #13, West Palm Beach, FL 33405 USA. Telephone +1 561 249 0088, E-Fax +1 561 828 7618, Email: IGSsec@geosyntheticssociety.org. Learn more here.;

The newest IGS News is available! Volume 26, No 2 from the International Geosynthetics Society (IGS) is content loaded, with significant reports from the IGS' quadrenniel International Conference on Geosynthetics, international chapters, election results, and much more. The issue also includes results from the first IGS Photo Competition, an in memorium column about the late Bernard Myles, IGS Award 2010 winners, regional conference announcements, and numerous other items. Read the latest in PDF today. Learn more here.;

Penton Media's 2010 Global Waste Management Symposium (GWMS), an international forum for the presentation of peer-reviewed applied and fundamental research and case studies on waste management, announces the Strategic and Media Partners for the event 3-6 October 2010 at the JW Marriott San Antonio Hill Country Resort and Spa. The GWMS is proud to be supported by Penton Media's Waste Age Magazine, as well as media support from the following Media Partners to date….

The American Public Works Association (APWA) 2011 Sustainability in Public Works Conference and exhibition is accepting presentation proposals through 30 September 2010. The event location and dates have yet to be announced, but 2010's event in Minneapolis was a great success. APWA's sustainability initiatives include not just this event series but a new APWA Center for Sustainability. Learn more about the conference topics that intersect with geosynthetic practice. Learn more here.;

The Brazilian infrastructure market is expanding rapidly. Over the next three years, USD $500 billion is expected to be invested, both to keep pace with the country's growth and two major international sporting events (2014 FIFA World Cup and 2016 Summer Olympic Games). These growth opportunities and more will be discussed at Terrapinn's Infrastructure Investment World Brazil 2010 conference, 31 August - 1 September 2010 in Rio de Janeiro. Key investors, developers, construction companies, government officials, development banks, and hedge and private equity funds will all be involved.

CompositesWorld, publisher of High-Performance Composites and Composites Technology magazines, has announced that the agenda is nearly set for its High-Performance Fibers 2010 conference, which will be held 9-10 November 2010, at the Doubletree Guest Suites Historic Charleston Hotel in Charleston, South Carolina. This year’s agenda will have some different presentations, including one on geotextiles that incorporate fiber optic sensors that provide structural health monitoring of critical earth structures like walls, slopes, roads, rails, levees and dams, identifying unseen problems before a catastrophic failure occurs. Learn more here.;

A US House of Representatives panel has signed off on a bill allocating $882 million for a public-works project intended to overhaul the Trinity River waterfront in downtown Dallas. The cash -- almost double the amount originally set aside for the improvements -- would be used to raise levees, implement new erosion-control measures, and build or rehabilitate several pump stations. Learn more here.;

During the week of 26 July 2010 Dr. Barry Christopher, a past president of the North American Geosynthetics Society (NAGS) and private geotechnical consultant, and David Suits, NAGS Executive Director, presented two one-and-a-half-day short courses on "Geosynthetics in Reinforcement Applications." These sessions were presented through the Cornell University Local Roads Technical Assistance Program (LTAP). Learn more.

Tensar geogrid technology has been used to solve the extensive ground stabilisation problems encountered in Kier's development of a major new supermarket in Newport, Gwent, United Kingdom. Located on the former Crindau coke-fuelled gasworks close to the banks of the River Usk, the store project is on track for completion before the 2010 Ryder Cup.

The Transportation Research Board's (TRB) Research in Progress website includes a note of a 9 July 2010-entered research program title "Geosynthetic Reinforced Soil for Low Volume Bridge Abutments." The Iowa Department of Transportation is heading the research, and the study is being carried out by Iowa State University Institute for Transportation. The project runs through 31 December 2011. Learn more here.;

A road in Nixa, Missouri that has been closed since May 12 after a county road foreman spotted the sinkhole, is reopening. The sinkhole measured about 2 feet in diameter but went back about 5 feet under the road, where it became about 5 feet deep. After several tests and borings done around the sinkhole, no other voids were found. However, the ground was to unstable to fill and repave. Crews used geogrid to reinforce the roadway, basically creating a structural bridge over the void. To accomplish that, a 100-by-24-foot section of the roadway, going about 5 feet deep, was removed. Learn more here.;

SKZ, with scientific committee support from Cemagref and the Geosynthetic Institute (GSI), will host the 3rd International Symposium on Geosynthetic Clay Liners (GBR-C 2k10) 15-16 September 2010 at the Fortress Marienberg in Würzburg, Germany. Technical sessions will address shear and mechanical behaviour of GCLs, chemical resistance of GCLs, testing of GCLs under unsaturated conditions, behaviour of GCLs in landfill covers (case studies), regulations, new concepts and developments in the use of GCLs, and GCLs for hydraulic and construction applications. Learn more.

Baum Publications' Canadian Environmental Protection changed its name in 2010 to Environmental Solutions Magazine. Read the latest at ESM now. Learn more here.;

In advance of the publication of the half-year figures on Thursday, 26 August 2010 and on the basis of provisional results, TenCate announces that its operating result (EBIT) amounts to approximately € 27 million in the second quarter of 2010 (second quarter of 2009: € 11.1 million). The operating result for the first six months of 2010 doubled to an amount of approximately € 33 million. Taking incidental items into account, net profit too doubled in the first half year to approximately € 19 million. Within this, the company reports significant improvement from its Geosynthetics and Grass division. Read more.

U.S. Environmental Protection Agency (EPA) Region 4 announced the release of the Sustainable Design and Green Building Toolkit for Local Governments (Toolkit). The Toolkit was developed collaboratively by the Agency's Regional Resource Conservation and Recovery Act Division and Water Protection Division and Pollution Prevention Office, with support from the EPA Green Building and Smart Growth Programs, the Office of Solid Waste and Emergency Response's Innovations Workgroup, and many external partners. The Toolkit is designed to assist local governments in identifying and removing permitting barriers to sustainable design and green building practices.