Assessing The Long Term Performance Of Mechanically Stabilized Earth Walls

"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.

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.

Long-Term Performance and Durability of Masonry Structures: Degradation Mechanisms, Health Monitoring and Service Life Design focuses on the long-term performance of masonry and historical structures. The book covers a wide range of related topics, including degradation mechanisms in different masonry types, structural health monitoring techniques, and long-term performance and service life design approaches. Each chapter reflects recent findings and the state-of-the-art, providing practical guidelines. Key topics covered include the theoretical background, transport properties, testing and modeling, protective measures and standards and codes. The book's focus is on individual construction materials, the composite system and structural performance. Covers all issues related to durability, including degradation mechanisms, testing and design, monitoring and service life design Focuses on different masonry construction types Presents a ‘one-stop’ reference for advanced postgraduate courses that focuses on the durability of masonry and historical constructions

This book presents select proceedings of the National conference on Geo-Science and Geo-Structures (GSGS 2020). It provides sustainable solutions to various challenges encountered in the field of geotechnical engineering. The topics presented include advanced characterization to study the behavior of geomaterials, shallow and deep foundations including tunneling, use of geosynthetics and other soil reinforcing materials in minimizing slope failures and landslides, dynamics of soils and foundations, and its connection with energy geotechnics, transportation geotechnics, and offshore geotechnics. The book further highlights various aspects of ground improvement techniques by incorporating the use of industrial by-products, forensic analyses of geo-structures, instrumentation and sensing techniques in geotechnical engineering and issues associated with geo-environmental engineering. The book will be a valuable reference for budding researchers, academicians, practitioners and policymakers interested in sustainable practices associated with geotechnical engineering and related domains.

This is an open access book. Rocscience is delighted to announce the Rocscience International Conference 2023 (RIC2023), an in-person gathering to be held from April 24–26, 2023, in Toronto, Canada. RIC2023's primary objective is to bring geotechnical professionals together to meet and exchange ideas on important issues and developments in geotechnical engineering, particularly combinations of emerging and mature technologies. The geotechnical industry is rapidly evolving. Engineers are more connected through technology, technology is becoming more integrated than ever, and methods combining these technologies are becoming more prevalent. This movement towards combining technologies led us to the conference theme, “Synergy in Geotechnical Engineering – Success Beyond Individual Technologies.” We believe the time is right to highlight how far the industry has come with various technologies and continues to develop. The conference aims to create an environment that fosters new perspectives and helps attendees delve deeper into innovative approaches. During RIC2023, Rocscience will award the 2023 Lifetime Achievement Medal to Dr. Norbert Morgenstern, an internationally recognized authority in the engineering community. As both a practitioner and educator, Dr. Morgenstern’s contributions to the geotechnical community continue to benefit engineers worldwide, and he will give an address on his career. In addition to keynotes by Dr. Morgernstern and four other distinguished speakers, there will be several technical and networking sessions.