Not a set of standards and practices, but a description of the Center's program, and advice on how manufacturers of retaining walls and other systems can take part in it. Discusses the background, the panel and consultant, evaluation methodology, program requirements, and deliverables. No index. Annotation copyrighted by Book News, Inc., Portland, OR
Not a set of standards and practices, but a description of the Center's program, and advice on how manufacturers of retaining walls and other systems can take part in it. Discusses the background, the panel and consultant, evaluation methodology, program requirements, and deliverables. No index. Annotation copyrighted by Book News, Inc., Portland, OR
"Mechanically stabilized earth (MSE) walls are an important class of infrastructure assets whose long-term performance depends on various factors. As with most all other classes of assets, MSE walls need periodic inspection and assessment of performance. To date, some agencies have established MSE wall monitoring programs, whereas others are looking for guidance, tools, and funding to establish their own monitoring programs. The objective of this synthesis project is to determine how transportation agencies monitor, assess, and predict the long-term performance of MSE walls. The information used to develop this synthesis came from a literature review together with a survey and interviews. Of the 52 U.S. and 12 Canadian targeted survey recipients, 39 and five, respectively, responded. This synthesis reveals that unlike bridges and pavements, MSE walls and retaining walls in general are often overlooked as assets. Fewer than one-quarter of state-level transportation agencies in the United States have developed some type of MSE wall inventory beyond that which may be captured as part of their bridge inventories. Fewer still have the methods and means to populate their inventories with data from ongoing inspections from which assessments of wall performance can be made. In the United States, there is no widely used, consistently applied system for managing MSE walls. Wall inventory and monitoring practices vary between agencies. This synthesis examines existing practices concerning the nature, scope, and extent of existing MSE wall inventories. It also examines the collection of MSE wall data, including the types of performance data collected, how they are maintained in wall inventories and databases, the frequency of inventory activities, and assessment practices relevant to reinforcement corrosion and degradation. Later parts of this synthesis discuss how MSE wall performance data are assessed, interpreted, and used in asset management decisions. This synthesis finds that the most well-implemented wall inventory and assessment system in the United States is the Wall Inventory Program developed by FHWA for the National Park Service. However, this system, like some others, uses 'condition narratives' in a process that can be somewhat cumbersome and subjective. Other systems use more direct numeric scales to describe wall conditions, and an advantage of such systems is that they are often compatible with those used in assessments of bridges. As experience with MSE walls accumulates, agencies will likely continue to develop, refine, and better calibrate procedures affecting design, construction, condition assessment, and asset management decisions. One portion of this synthesis is dedicated to summarizing the actions taken thus far by survey respondents to improve the long-term performance of their MSE walls. Many agencies prescribe the use of a pre-approved wall design and/or wall supplier. Other actions or policies frequently focus on drainage-related issues."--Summary.
Prepared by the Environmental Technology Evaluation Center (EvTEC), a CERF Service Center. This report describes the nature and scope of an environmental evaluation of ThermoEnergy Corporation's Ammonia Recovery Process (ARP) System, a method for recycling ammonia in wastewater. The data in this report were collected over a three-month pilot study.ØTests found that the ARP system is capable of removing 75?99% of the ammonia in the waste stream in a domestic wastewater treatment plant. The ARP System uses a series of absorption, evaporation, and crystallization steps to convert ammonia in wastewater into a commercial fertilizer, ammonium sulfate. The evaluation results clearly indicate that the ARP process is capable of achieving significant ammonia reduction under a range of environmental conditions
Prepared by the Highway Innovative Technology Evaluation Center, a CERF service center. This report presents the results of a HITEC evaluation of the Isogrid Retaining Wall System, designed and developed by the Neel Company. The report describes the basic capabilities and limitations of the Isogrid System for use as a technically viable precast, mechanically stabilized earth retaining wall system. The evaluation was conducted based on material, design, construction, performance, and quality assurance information outlined in the HITEC Protocol. The Isogrid System features a diamond-shaped, segmental precast concrete facing panel with weep holes where four panels intersect and welded wire, grid-type soil reinforcement attached to the center of each facing panel.
Prepared by the Highway Innovative Technology Evaluation Center (HITEC), a CERF/IIEC Innovation Center. This report describes a HITEC evaluation designed to determine the basic capabilities and limitations of the Terramesh Retaining Wall System for use as a technically viable, mechanically stabilized earth, retaining wall system. The evaluation was conducted based on material, design, construction, performance, and quality assurance mainformation outlined in the HITEC Protocol. The Terramesh System, supplied by Maccaferri, Inc.,Øfeatures a Gabion basket facing of various configurations and metal double-twisted grid type of soil reinforcement, which is manufactured integrally with the basket facing blocks.
Earth reinforcement techniques are used worldwide, providing dependable solutions to a wide range of geotechnical engineering problems.Well-established earth reinforcement technologies are regularly augmented by new materials, innovative construction techniques and advances in design and analysis. Furthermore, reinforced earth structures are increasingly seen as expedient and economical techniques in disaster situations, such as earthquakes, flooding or tsunamis. NEW HORIZONS in EARTH REINFORCEMENT contains contributions from the 5th International Symposium on Earth Reinforcement, Kyushu, Japan, 14-16 November 2007, and presents the very latest earth reinforcement techniques and design procedures. The volume showcases advances in materials and emerging applications, with special emphasis on disaster mitigation and geoenvironmental issues. The book will be invaluable to academics and professionals in geotechnical engineering.
Prepared by the Highway Innovative Technology Evaluation Center (HITEC), a CERF Innovation Center. This report describes an evaluation to determine the capabilities and limitations of the KeySystem I Retaining Wall System, a mechanically stabilized earthØstructure developed, designed, and supplied by Keystone Retaining Wall Systems, Inc. The evaluation was conducted based on design, construction, performance, and quality assurance information outlined in the HITEC Protocol. KeySystem I features modular block facing to which KeyStrips are attached. KeyStrips are structural welded wire, grid-type reinforcement produced from high-strength steel.
Prepared by the Highway Innovative Technology Evaluation Center, a CERF/IIEC Innovation Center. This report describes a HITEC evaluation designed to determine the basic capabilities and limitations of the Tricon System for use as a technically viable, precast, mechanically stabilized earth-retaining wall system. The evaluation considered material, design, construction, performance, and quality assurance information outlined in the HITEC Protocol.
