Download or read book Evaluation of Corrosion of Metallic Reinforcements and Connections in MSE Retaining Walls written by Christopher L. Raeburn and published by . This book was released on 2008 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanically Stabilized Earth (MSE) retaining walls have become the dominant retained wall system on ODOT projects. The permanent MSE walls constructed on ODOT projects, in recent years, use metallic reinforcements and facing connections buried directly in the backfill soil. Accelerated deterioration of these structural elements would have serious financial and safety impacts for the Department. Classical MSE wall design incorporates an estimate of deterioration of reinforcement by corrosion. Monitoring of actual corrosion performance, however, is an important element of managing the current inventory of MSE walls. Monitoring could answer key questions that can provide for the best management of the existing walls, and provide feedback to the design process for future installations. This report details a literature review of methods for estimating and measuring deterioration of structural reinforcing elements in both concrete and MSE walls. It also presents a selected history of metallic reinforcement design specification and utilization. A listing of the MSE walls that can be identified in the ODOT Bridge Data System is included.

Download or read book Long Term Corrosion of Reinforcing Strips in Mechanically Stabilized Earth Walls written by Brandon Seth Berke and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ABSTRACT: Mechanically stabilized earth (MSE) walls are a more advanced form of a retaining wall, often larger and able to hold back more backfill. This is achieved by reinforcing strips or meshes (most often galvanized steel) placed into the soil, which are held in place by friction. The strips mechanically stabilize the earth while undergoing tension. The wall is covered with concrete medallions that connect to the reinforcements. The medallions have only a secondary structural role in holding up the wall but provide cover that protects the soil from washing away. MSE walls are structures expected to have very long service lives (e.g. 100 years). Confirmation is needed that such durability can be achieved, especially to show that the progression of corrosion of the reinforcement is slow enough. Ten MSE walls around Florida were instrumented (electrical connections were made through the concrete covers to the buried elements) between 1996- 1998 and used to survey corrosion rates of galvanized strip or mesh soil reinforcements. Initial estimates of corrosion-related durability were obtained at that time, indicating a good prognosis for long term durability. The objective of the research in this thesis was to obtain additional indications of the durability of reinforcements in MSE walls in Florida so as to perform a more reliable projection of future performance. Corrosion behavior was measured at the same locations as the initial survey by electrochemical nondestructive tests and by destructive tests. The nondestructive testing consisted of half-cell potentials, polarization resistance measurements, and electrochemical impedance spectroscopy. Corrosion rates reported in this thesis are based upon polarization resistance measurements. The destructive testing consisted of soil extraction and hardware extraction. Hardware extraction enabled independent verification of estimates of electrochemical corrosion rate. Analysis of extracted soil verified that soil composition was within construction specifications. The data from the current survey were also used to further improve prediction of corrosion. The present series of evaluations confirm that the structures are performing as desired based upon the updated model projection of future corrosion.

Download or read book Evaluation of the SSL MSE Plus Retaining Wall System written by Highway Innovative Technology Evaluation Center (U.S.) and published by ASCE Publications. This book was released on 2001-01-01 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prepared by the Highway Innovative Technology Evaluation Center (HITEC), a CERF service center. This report describes a HITEC evaluation designed to determine the basic capabilities and limitations of the MSE Plus System, manufactured by SSL, LLC, for use as a mechanically stabilized earth retaining system. The evaluation was conducted based on material, design, construction, performance, and quality assurance information outlined in the HITEC Protocol. TheØMSE PlusØSystem features rectangular segmental precast concrete facing panels and galanized welded wire, grid-type soil reinforcement.

Download or read book Assessment of In situ Corrosion Conditions at Nevada Mechanically Stabilized Earth Wall Sites written by Nelson Pearson and published by . This book was released on 2015 with total page 572 pages. Available in PDF, EPUB and Kindle. Book excerpt: The inability of soil to provide sufficient tensile strength presents challenges for soils being used as a structural building material. However, it is possible to improve the structural performance with the inclusion of a reinforcing system. The development of these systems has been a major advancement of the civil engineering practice. Mechanically stabilized earth (MSE) wall systems typically consist of a: concrete facing panel, specified backfill, reinforcing elements, and the retained fill. The interaction of the backfill with the reinforcements, and the reinforcements with the facing panels, produces a system that when properly designed, can be a cost effective engineering solution. In Nevada there are over 150 MSE walls that have been constructed using metallic reinforcements (Thornley 2009). Corrosion of metallic elements a naturally occurring electrochemical process is irreversible an inevitable. The rate of metal loss (corrosion) is a function of the environmental conditions and metal type. For MSE walls key parameters include the backfill's: salt content, organic content, saturation level, as well as the metal type of the reinforcements. Nevada has two previous corrosion investigations, an extensive site investigation at I-515/ Flamingo Rd. and a statistical analysis of as-built soil records along with a preliminary investigation for I-15/ Cheyenne Blvd. These studies form the foundation for this investigation of in-situ corrosion conditions. Seven MSE wall sites were investigated using electrochemical backfill characterization and linear polarization resistance (LPR) corrosion rate monitoring. Evaluation of electrochemical backfill characteristics has resulted in the discovery of six sites that fail current NDOT/ AASHTO MSE wall backfill requirements. The in-situ soil samples collected and analyzed more than doubled the available data used to describe the corrosiveness of the backfill. Linear polarization resistance corrosion rates were obtained for more than 200 different elements. These data suggest that despite the aggressive nature of the backfill, most elements are preforming well and are below the anticipated rates. However, several elements were discovered with corrosion rates in excess of five times the design model. The use of the LPR corrosion monitoring has concluded that the conditions at I-15/ and Cheyenne Blvd. are equivalent to or worse than the conditions evaluated in 2004 at the I-515/ Flamingo Rd. complex. The discoveries at Flamingo Rd. led to remediation of the largest wall at the complex. Through the use of electrochemical backfill characteristics and LPR corrosion rates, the seven sites investigated have been ranked. The rankings are dependent on several factors such as backfill electrochemical conditions and comparison of corrosion rates data with design models. This study has confirmed that observations of conditions along the exterior of the wall are not sufficient when determining the condition of the soil reinforcements. Routine corrosion monitoring is required to monitor the depletion of the soil reinforcements and should be incorporated into a Long-term Corrosion Monitoring and Asset Management Plan (LCMAMP). It is anticipated that a program will be integrated into Nevada's current asset management systems. The development and implementation of LCMAMP, directly reflects the federal initiative for systematic detailed evaluation of critical assets, MAP-21.

Download or read book Evaluation of the Retained Earth MSE Wall System by Foster Geotechnical a Division of L B Foster Company written by Highway Innovative Technology Evaluation Center (U.S.) and published by ASCE Publications. This book was released on 2005-01-01 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of the ISOGRID Retaining Wall System written by Highway Innovative Technology Evaluation Center (U.S.) and published by ASCE Publications. This book was released on 1999-01-01 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Evaluation of the Maccaferri Terramesh System Retaining Wall written by Highway Innovative Technology Evaluation Center (U.S.) and published by ASCE Publications. This book was released on 2002-01-01 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Proceedings of the Annual Symposium on Engineering Geology Geotechnical Engineering written by and published by . This book was released on 1999 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Corrosion Behavior of Galvanized Steel Reinforcements in MSE Walls in the Presence of Soil Organics written by Claudia Aide Soriano Vazquez and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book LRFD Metal Loss and Service life Strength Reduction Factors for Metal reinforced Systems written by Kenneth L. Fishman and published by Transportation Research Board National Research. This book was released on 2011 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: TRB's National Cooperative Highway Research Program (NCHRP) Report 675: LRFD Metal Loss and Service-Life Strength Reduction Factors for Metal-Reinforced Systems explores the development of metal loss models for metal-reinforced systems that are compatible with the American Association of State Highway and Transportation Officials' Load and Resistance Factor Design Bridge Design Specifications.

Download or read book Recommendations for Design and Analysis of Earth Structures using Geosynthetic Reinforcements EBGEO written by Deutsche Gesellschaft für Geotechnik and published by John Wiley & Sons. This book was released on 2012-01-09 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: The completely revised and extended Recommendations deal with all questions relevant to the planning and dimensioning of geosynthetics-reinforced earth structures. In addition to the demands on materials and analysis principles, the applications of geosynthetics in a range of foundation systems, ground improvement measures, highways engineering projects, in slopes and retaining structures, and in landfill engineering are discussed. The Recommendations have been supplemented by the following sections: - reinforced earth structures over point or linear bearing elements, - foundation systems using geotextile-encased columns, - bridging subsidence, - dynamic actions of geosynthetic-reinforced systems. The remaining sections have been fundamentally revised and updated in line with current standards and codes of practice.

Download or read book Asset Management Inventory and Data Collection written by and published by . This book was released on 2009 with total page 298 pages. Available in PDF, EPUB and Kindle. Book excerpt: An efficient and accurate inventory of a state highway agency's assets, along with the means to assess the condition of those assets and model their performance, is critical to enabling an agency to make informed investment decisions in a Transportation Asset Management (TAM) environment. Today, new technologies provide fast and improved ways to gather, process, and analyze data. The key is to identify and gather the most useful, reliable, cost-effect information and use it to make informed decisions for asset management. Four key infrastructure areas have been identified as primary asset components; pavements, bridges, geotechnical features, and roadside appurtenances. Each area contains multiple categories and data elements important for sound decision making. Although some similarities exist in these four primary categories, the nature of data collection may differ, depending on the asset type. The, sheer number of data elements and the length of asset networks for pavements and roadside appurtenances render the automated highway speed data collection method a necessity rather than a luxury. However, the discrete nature of bridges and geotechnical features make the automated mobile data collection method on a network level unfeasible with today's technology. Important issues in the collection process include precision, subjectivity and variability of the process itself, as well as speed, safety of the survey crew, proximity of the public, cost, etc. Although previous research has attempted to address these issues and determine the most appropriate method(s), the question remains as to which roadway data collection system is best for state highway agencies given real world constraints. This research set up a "sealed envelope" experiment wherein the identification, location, description, and quality of the asset data elements are known only to NCSU researchers. Vendors are informed of only the data necessary to perform their evaluation. To support this effort at 95-mile test course near Raleigh, North Carolina was identified, which contained a sampling of pavement, roadside, geotechnical and bridge elements. This document reports on the findings from the study

Download or read book Geosynthetic Reinforced Soil GRS Walls written by Jonathan T. H. Wu and published by John Wiley & Sons. This book was released on 2019-07-10 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book to provide a detailed overview of Geosynthetic Reinforced Soil Walls Geosynthetic Reinforced Soil (GRS) Walls deploy horizontal layers of closely spaced tensile inclusion in the fill material to achieve stability of a soil mass. GRS walls are more adaptable to different environmental conditions, more economical, and offer high performance in a wide range of transportation infrastructure applications. This book addresses both GRS and GMSE, with a much stronger emphasis on the former. For completeness, it begins with a review of shear strength of soils and classical earth pressure theories. It then goes on to examine the use of geosynthetics as reinforcement, and followed by the load-deformation behavior of GRS mass as a soil-geosynthetic composite, reinforcing mechanisms of GRS, and GRS walls with different types of facing. Finally, the book finishes by covering design concepts with design examples for different loading and geometric conditions, and the construction of GRS walls, including typical construction procedures and general construction guidelines. The number of GRS walls and abutments built to date is relatively low due to lack of understanding of GRS. While failure rate of GMSE has been estimated to be around 5%, failure of GRS has been found to be practically nil, with studies suggesting many advantages, including a smaller susceptibility to long-term creep and stronger resistance to seismic loads when well-compacted granular fill is employed. Geosynthetic Reinforced Soil (GRS) Walls will serve as an excellent guide or reference for wall projects such as transportation infrastructure—including roadways, bridges, retaining walls, and earth slopes—that are in dire need of repair and replacement in the U.S. and abroad. Covers both GRS and GMSE (MSE with geosynthetics as reinforcement); with much greater emphasis on GRS walls Showcases reinforcing mechanisms, engineering behavior, and design concepts of GRS and includes many step-by-step design examples Features information on typical construction procedures and general construction guidelines Includes hundreds of line drawings and photos Geosynthetic Reinforced Soil (GRS) Walls is an important book for practicing geotechnical engineers and structural engineers, as well as for advanced students of civil, structural, and geotechnical engineering.

Download or read book Underground Corrosion written by Melvin Romanoff and published by N A C E International. This book was released on 1989 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improved Seismic Design Criteria for California Bridges written by and published by . This book was released on 2000 with total page 404 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book LRFD Guide Specifications for the Design of Pedestrian Bridges written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 2009 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Performance Based Specifications and Control of Concrete Durability written by Hans Beushausen and published by Springer. This book was released on 2015-09-24 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work gives an overview of significant research from recent years concerning performance-based design and quality control for concrete durability and its implementation. In engineering practice, performance approaches are often still used in combination with prescriptive requirements. This is largely because, for most durability test methods, sufficient practical experience still has to be gained before engineers and owners are prepared to fully rely on them. This book, compiled by RILEM TC 230-PSC, is intended to assist efforts to successfully build the foundation for the full implementation of performance-based approaches through the exchange of relevant knowledge and experience between researchers and practitioners worldwide.