Creating a more efficient reinforcement for Mechanically Stabilized Earth (MSE) Walls is important because it will reduce the amount of material needed to construct MSE walls, and will reduce overall construction costs for companies and contractors. This thesis explores four main geometries of metallic crimped and metallic crossbar type reinforcement constructed with both, smooth steel and #4 rebar steel. Metal round bar was chosen because, compared to metallic rectangular strip reinforcements, there is less surface area in contact with the soil which will then reduce the amount of corrosion loses. Throughout testing, it was found that crimped metal round bar was able to produce the required pullout resistance but created too much extensibility (the amount of length the crimps straightened). The reinforcement made with crossbars and metal round bar were found to produce the required amount of pullout resistance with little to no extensibility.
This text outlines the problems commonly encountered during infrastructure constructions on soft and subsiding ground in lowland environments, and their solutions in terms of soil/ground improvement techniques.
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.
"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.
This book gathers selected proceedings of the annual conference of the Indian Geotechnical Society, and covers various aspects of soil dynamics and earthquake geotechnical engineering. The book includes a wide range of studies on seismic response of dams, foundation-soil systems, natural and man-made slopes, reinforced-earth walls, base isolation systems and so on, especially focusing on the soil dynamics and case studies from the Indian subcontinent. The book also includes chapters addressing related issues such as landslide risk assessments, liquefaction mitigation, dynamic analysis of mechanized tunneling, and advanced seismic soil-structure-interaction analysis. Given its breadth of coverage, the book offers a useful guide for researchers and practicing civil engineers alike.
"In the United States it is estimated that 75 percent of all roads are low volume roads maintained by some 35,000 local agencies. Low volume roads often omit surface slope protection, and this can lead to slope failure, erosion, and maintenance, safety, and ecological issues. This report presents information on cost effective and sustainable road slope stabilization techniques, with a focus on shallow or near surface slope stabilization and related erosion control methods used on low volume roads. To fully address this topic, planning and site investigation are discussed, as well as erosion control techniques, soil bioengineering and biotechnical techniques, mechanical stabilization, and earthwork techniques. Information presented in this report was obtained through an extensive literature review, and from survey and interview responses. From the survey responses, 30 individuals were interviewed based on the information they made available in the survey. A total of 25 interviews were conducted over the phone, and in two cases written responses were received"--Preface.
GSP 230 contains 39 papers on applied geotechnical engineering in soft ground construction, reinforced soils, and fundamental soil behavior presented in honor of Robert D. Holtz.
This book comprises select proceedings of the annual conference of the Indian Geotechnical Society. The conference brings together research and case histories on various aspects of geotechnical and geoenvironmental engineering. The book presents papers on geotechnical applications and case histories, covering topics such as (i) Characterization of Geomaterials and Physical Modelling; (ii) Foundations and Deep Excavations; (iii) Soil Stabilization and Ground Improvement; (iv) Geoenvironmental Engineering and Waste Material Utilization; (v) Soil Dynamics and Earthquake Geotechnical Engineering; (vi) Earth Retaining Structures, Dams and Embankments; (vii) Slope Stability and Landslides; (viii) Transportation Geotechnics; (ix) Geosynthetics Applications; (x) Computational, Analytical and Numerical Modelling; (xi) Rock Engineering, Tunnelling and Underground Constructions; (xii) Forensic Geotechnical Engineering and Case Studies; and (xiii) Others Topics: Behaviour of Unsaturated Soils, Offshore and Marine Geotechnics, Remote Sensing and GIS, Field Investigations, Instrumentation and Monitoring, Retrofitting of Geotechnical Structures, Reliability in Geotechnical Engineering, Geotechnical Education, Codes and Standards, and other relevant topics. The contents of this book are of interest to researchers and practicing engineers alike.
As a Federal Highway Administration design reference for highway projects, this report was prepared to enable the engineer to identify and evaluate potential applications of shored mechanically stabilized earth (SMSE) walls. Included in this design guideline are a literature review on similar construction and the results and interpretation of field-scale testing, centrifuge modeling, and numerical modeling of an SMSE wall system. Results of the centrifuge modeling and field-scale testing show that reduction of the reinforcement length to as little as 25 percent of the wall height (0.25H) provides sufficient wall stability, even under a considerably high degree of surcharge loading. Using the results of the modeling and field testing research, this design guideline recommends a minimum reinforcement length equivalent to as little as 30 percent of the wall height (0.3H) for the MSE wall component, provided that the MSE reinforcement length is greater than 1.5 m. The benefit of attaching reinforcement to the shoring wall is found to be small and is generally not recommended except by way of the upper two layers of reinforcement. If possible, these layers of reinforcement should overlap the shoring wall and have a total length of 0.6H. If this is not possible, then these layers should be attached to the shoring wall. Internal design requirements of the MSE wall component for an SMSE wall system differ from that of a traditional MSE wall. Equations presented in this design guideline have been developed specifically to address these requirements. The benefits of increased retaining abilities provided by the shoring wall, such as reduction in lateral load acting on the MSE wall component and contribution to global stability, are considered in the design process.
