Download or read book Development of Stiffness based Specifications for In situ Embankment Compaction Quality Control written by Kansas. Department of Transportation. Bureau of Materials & Research and published by . This book was released on 2007 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compaction of embankment soils is a key factor influencing premature pavement distresses and bridge approach settlement. The current specifications of the Kansas Department of Transportation (KDOT) address embankment compaction in terms of density and moisture content. However, the implementation of performance-based specifications would require measuring mechanical properties of soil, such as stiffness, in addition to density. This is needed because soil stiffness is the parameter used to characterize the embankment soil in the design of pavement structures. The objectives of this study were to investigate the use of the Light Falling Weight Deflectometer (L-FWD) to measure in-situ soil stiffness and to investigate the feasibility of developing a stiffness-based specification for embankment soil compaction quality control. To achieve these objectives, soil stiffness values were measured at multiple locations along nine KDOT embankment projects using the Prima 100 L-FWD. Concurrent density and moisture measurements were also taken at select locations. Bulk soil samples were collected and remolded soil samples were used to measure the resilient moduli of the soils in the laboratory at varying density and moisture contents. For each soil, and at each combination moisture content and dry density level used in the laboratory tests, a constitutive model was derived from the laboratory resilient modulus data to capture the stress-dependent behavior of the soil. The constitutive model was then implemented in a finite element model of a semi-infinite soil half-space to compute the deflection at the surface of the half-space for a circular load. An equivalent elastic modulus for the soil half-space was back-estimated with the Boussinesque formula, for each combination moisture content and dry density. A regression model was then developed to relate the equivalent elastic modulus of the soil half-space to the dry density and moisture content of the soil. The regression model was used to predict the equivalent elastic moduli for the in-situ moisture contents and dry density values recorded during the field L-FWD tests. The predicted equivalent moduli were then compared to the moduli measured by the L-FWD. It was found that the equivalent moduli predicted from the results of the laboratory resilient modulus tests do not correlate with the in-situ soil stiffness measured with the L-FWD. This prevented the development of a quality control scheme based on laboratory measured resilient moduli. The high degree of spatial variability obtained for the in-situ moduli measured with the L-FWD prevented the development of a quality control scheme based on a control test strip.
Download or read book QA QC of Subgrade and Embankment Construction written by Eshan Ganju and published by . This book was released on 2015-09-01 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Dynamic Cone Penetrometer (DCP) is a device that is used for the estimation of in situ compaction quality of constructed subgrades and embankments. It is a relatively inexpensive, light-weight and easy to use device that measures the dynamic penetration resistance of the compacted soil, from which an estimate of soil strength and stiffness characteristics can be made. Owing to its ease of use, many DOTs in the U.S. have employed the DCP in their compaction quality control procedures, and over the past few decades, extensive research has been carried out on the development of correlations between the results of the DCP test and the results of strength and stiffness tests performed on compacted soils (e.g., California bearing ratio, and resilient modulus)The objectives of this research are to refine DCP-based quality assurance and quality control correlations for compaction quality control developed by previous research studies carried out at Purdue for the Indiana Department of Transportation, especially focusing on (1) grouping of the soils based on their mechanical response to the DCP loading, and (2) limiting the in situ moisture range of the soils used for development of correlations within -2% of the optimum moisture content of the tested soil. The factors outlined above are studied, and in particular, soil grouping is examined critically. The AASHTO ('A-based') classification employed previously for classification of soils is replaced with a new classification criteria specifically developed for the DCP test. Soils are grouped into one of the two categories of coarse-grained or fine-grained soils on the basis of the size of the dominant particle in the soil. The criteria developed for the classification of soil into one of these two categories is based on index properties of the soil, such as the standard Proctor maximum dry density, optimum moisture content, plasticity index (PI) and fines content.
Download or read book Performance Specifications for Rapid Highway Renewal written by Sidney Scott III and Linda Konrath and published by Transportation Research Board. This book was released on with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report from the second Strategic Highway Research Program (SHRP 2), which is administered by the Transportation Research Board of the National Academies, describes suggested performance specifications for different application areas and delivery methods that users may tailor to address rapid highway renewal project-specific goals and conditions.
Download or read book Advances in Materials and Pavement Performance Prediction II written by K. Anupam and published by CRC Press. This book was released on 2020-12-08 with total page 501 pages. Available in PDF, EPUB and Kindle. Book excerpt: Inspired from the legacy of the previous four 3DFEM conferences held in Delft and Athens as well as the successful 2018 AM3P conference held in Doha, the 2020 AM3P conference continues the pavement mechanics theme including pavement models, experimental methods to estimate model parameters, and their implementation in predicting pavement performance. The AM3P conference is organized by the Standing International Advisory Committee (SIAC), at the time of this publication chaired by Professors Tom Scarpas, Eyad Masad, and Amit Bhasin. Advances in Materials and Pavement Performance Prediction II includes over 111 papers presented at the 2020 AM3P Conference. The technical topics covered include: - rigid pavements - pavement geotechnics - statistical and data tools in pavement engineering - pavement structures - asphalt mixtures - asphalt binders The book will be invaluable to academics and engineers involved or interested in pavement engineering, pavement models, experimental methods to estimate model parameters, and their implementation in predicting pavement performance.
Download or read book Intelligent Compaction of Soils written by Philip Dunston and published by . This book was released on 2018-08-15 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes a study of intelligent compaction (IC) technologies, within the context of actual construction projects, for its potential as a component of INDOT's QC/QA for soils. The output from an IC-equipped roller compaction equipment is a real-time area mapping of the compacted lift stiffness as captured by the IC measure. Data was collected to evaluate the correlation between each of two IC measures-compaction meter value (CMV) and machine drive power (MDP)-and in situ embankment quality test measures, the chief in situ test being the dynamic cone penetrometer (DCP) test which INDOT uses for soil embankment acceptance testing. Researchers sought to understand how well the IC measures might assess embankment quality as currently evaluated by the in situ measures. Window-averaged IC measures were compared with the in situ DCP test points. For CMV, a variable correlation was found between the average CMV and DCP values from 74 in situ locations. Also, a limited head-to-head comparison of CMV and MDP with the in situ measures provided some indication that MDP should be studied further. Lessons were learned regarding the elimination of bias in future correlation studies, critical provisions to facilitate best data quality, and important aspects of data management. IC technology holds promise for monitoring the consistency of the soil compaction effort and flagging weak areas in real time during compaction operations. However, further insight is needed regarding the correlation of the DCP measure with both types of IC measures for various soil characterizations and field moisture conditions.
Download or read book Bearing Capacity of Roads Railways and Airfields written by Andreas Loizos and published by CRC Press. This book was released on 2017-07-20 with total page 3209 pages. Available in PDF, EPUB and Kindle. Book excerpt: Bearing Capacity of Roads, Railways and Airfields includes the contributions to the 10th International Conference on the Bearing Capacity of Roads, Railways and Airfields (BCRRA 2017, 28-30 June 2017, Athens, Greece). The papers cover aspects related to materials, laboratory testing, design, construction, maintenance and management systems of transport infrastructure, and focus on roads, railways and airfields. Additional aspects that concern new materials and characterization, alternative rehabilitation techniques, technological advances as well as pavement and railway track substructure sustainability are included. The contributions discuss new concepts and innovative solutions, and are concentrated but not limited on the following topics: · Unbound aggregate materials and soil properties · Bound materials characteritics, mechanical properties and testing · Effect of traffic loading · In-situ measurements techniques and monitoring · Structural evaluation · Pavement serviceability condition · Rehabilitation and maintenance issues · Geophysical assessment · Stabilization and reinforcement · Performance modeling · Environmental challenges · Life cycle assessment and sustainability Bearing Capacity of Roads, Railways and Airfields is essential reading for academics and professionals involved or interested in transport infrastructure systems, in particular roads, railways and airfields.
Download or read book Embankment Quality written by and published by . This book was released on 1998 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Phase I was initiated as a result of internal Iowa Department of Transportation (Iowa DOT) studies that raised concerns about the quality of embankments being constructed. Some large embankments have recently developed slope stability problems. In addition, pavement roughness has been noted shortly after roads were opened to traffic. This raised the question as to whether the current Iowa DOT embankment construction specifications are adequate. The primary objective of Phase I was to evaluate the quality of embankments being constructed under the current Iowa DOT specifications. The project was initiated in May 1997 with a tour of several embankment projects being constructed around the state. At each of these projects the resident construction engineer, field inspector, and contractor were interviewed with respect to their opinion of the current specifications. From construction observations and discussion during these visits it became obvious that there were problems with the current embankment construction specifications. Six embankment projects were selected for in-depth analysis and to represent the full range of soil types being used across the state. The results of Phase I field and laboratory construction testing and observations and post construction testing are presented in this report. Overall evaluation of the results of Phase I indicate that Iowa is not consistently obtaining a quality embankment constructed under the current Iowa DOT specifications. Based on these results, recommendations are made for Phase II to evaluate alternative specifications and develop rapid field methods for compaction control and soil identification.
Download or read book Soil Stiffness Evaluation for Compaction Control of Cohesionless Embankments written by Farhana Rahman and published by . This book was released on 2008 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mechanistic pavement design procedures based on elastic layer theory require characterization of pavement layer materials including subgrade soil. This paper discusses the subgrade stiffness measurements obtained from a new compaction roller for compaction control on highway embankment projects in Kansas. Three test sections were compacted using a single, smooth steel drum intelligent compaction (IC) roller that compacts and simultaneously, measures stiffness values of the compacted soil. Traditional compaction control measurements such as, density, in-situ moisture content, stiffness measurements using a soil stiffness gage, surface deflection tests using the light falling weight deflectometer (LFWD) and falling weight deflectometer (FWD), and penetration tests using a dynamic cone penetrometer (DCP), were also done. The results show that the IC roller was able to identify the locations of lower soil stiffness in the spatial direction. Thus, an IC roller can be used in proof rolling. IC roller stiffness showed sensitivity to the field moisture content indicating that moisture control during compaction is critical. No universal correlation was observed among the IC roller stiffness, soil gage stiffness, back-calculated subgrade moduli from the LFWD and FWD deflection data, and the California bearing ratio obtained from DCP tests. The discrepancy seems to arise from the fact that different pieces of equipment were capturing response from different volumes of soil on the same test section.
Download or read book Practices for Unbound Aggregate Pavement Layers written by E. Tutumluer and published by . This book was released on 2013 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 445: Practices for Unbound Aggregate Pavement Layers consolidates information on the state-of-the-art and state-of-the-practice of designing and constructing unbound aggregate pavement layers. The report summarizes effective practices related to material selection, design, and construction of unbound aggregate layers to potentially improve pavement performance and longevity."--Publisher website.
Download or read book A Comparison of Density Based and Modulus Based In Situ Test Measurements for Compaction Control written by Christopher L. Meehan and published by . This book was released on 2012 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents and compares the results from a series of in situ density-based and modulus-based compaction control tests that were conducted during construction of a coarse-grained soil embankment. To simulate current construction practices as closely as possible, these in situ tests were performed on an embankment that was constructed and compacted by a vibratory smooth drum roller in a series of lifts. During construction of the test embankment, the compaction process was monitored using the nuclear density gauge device and a number of alternative modulus-based devices, including the lightweight deflectometer, the dynamic cone penetrometer, and the soil stiffness gauge. Comparison of the in situ test results illustrates that point-to-point variability in measured values is quite common for each of these test devices, to varying degrees for the different devices that were examined. Consistent increases in measured soil properties from pass-to-pass of the compactor are considered critical for proper control of the compaction process, with some devices faring better than others in this area of performance. The measured modulus values correlated poorly to the nuclear density gauge dry unit weights, and also correlated poorly with other measured moduli when the results from different devices were compared. This lack of agreement was likely caused by a variety of factors including: variations in the magnitude of strain and rate of strain application between the different modulus-based devices, variations in the tested volume between the different devices, and variations in the local moisture content and matrix suction conditions. Finally, the effect of soil moisture content was shown to be critically important when interpreting the results from modulus-based tests, and the utility of multiple regression analyses was explored for including this effect.
Download or read book The Deep Mixing Method written by Masaki Kitazume and published by CRC Press. This book was released on 2013-02-21 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Deep Mixing Method (DMM), a deep in-situ soil stabilization technique using cement and/or lime as a stabilizing agent, was developed in Japan and in the Nordic countries independently in the 1970s. Numerous research efforts have been made in these areas investigating properties of treated soil, behavior of DMM improved ground under static and d
Download or read book Highway Progress written by United States. Bureau of Public Roads and published by . This book was released on 1963 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Focus written by and published by . This book was released on 2008 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Earthworks written by Burt G. Look and published by CRC Press. This book was released on 2022-09-22 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: Case studies are used to show how theory is applied in practice. In the design and construction process, various models are used – geotechnical, laboratory, analytical, delivery, and economic models as the project is developed from planning to construction. This book explores the use and limitations of these earthwork models to be understood and appropriately applied. This book evolved from an earthworks course to practicing engineers over a 10-year period. Theory alone is not enough. Experience alone without relating back to theory can sometimes be misleading if transferred without understanding the fundamentals. The book benefited from the experiences of those many practicing engineers and the author’s experience in multi-disciplinary consulting companies as well as specialist geotechnical companies and government departments. The basics of soil, rock and compaction mechanics as applied to field conditions are covered. Material typically not covered in other textbooks, include the applications and limitations of associated "standard" laboratory and field testing. Specific chapters are dedicated to excavation, subgrade and expansive clay assessment and treatment. Useful design practices as well as the development and application of specifications is covered. A specification, test or design in one climatic condition or geology may not apply in another.
Download or read book Geotechnical Instrumentation for Monitoring Field Performance written by John Dunnicliff and published by John Wiley & Sons. This book was released on 1993-10-06 with total page 602 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first book on the subject written by a practitioner forpractitioners. Geotechnical Instrumentation for Monitoring FieldPerformance Geotechnical Instrumentation for Monitoring FieldPerformance goes far beyond a mere summary of the technicalliterature and manufacturers’ brochures: it guides readersthrough the entire geotechnical instrumentation process, showingthem when to monitor safety and performance, and how to do it well.This comprehensive guide: * Describes the critical steps of planning monitoring programsusing geotechnical instrumentation, including what benefits can beachieved and how construction specifications should bewritten * Describes and evaluates monitoring methods and recommendsinstruments for monitoring groundwater pressure, deformations,total stress in soil, stress change in rock, temperature, and loadand strain in structural members * Offers detailed practical guidelines on instrument calibrations,installation and maintenance, and on the collection, processing,and interpretation of instrumentation data * Describes the role of geotechnical instrumentation during theconstruction and operation phases of civil engineering projects,including braced excavations, embankments on soft ground,embankment dams, excavated and natural slopes, undergroundexcavations, driving piles, and drilled shafts * Provides guidelines throughout the book on the best practices
Download or read book Work of the Public Roads Administration written by United States. Bureau of Public Roads and published by . This book was released on 1961 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Instrumentation Monitoring and Surveillance Embankment Dams written by A.D.M Penman and published by Routledge. This book was released on 2018-05-02 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt: Besides giving an historical introduction to embankment dams the book describes the need for instrumentation, planning procurement and installation practices of instruments. The significance of visual inspection and techniques, of monitoring various parameters, seepage, pore pressure, surface and internal displacements, earth pressures and seismic behaviour, through instrumentation has been described. Collection and processing of data and their use for back analysis to check stability of a dam at various stages of construction and reservoir filling have been suggested. In addition to case histories quoted in various chapters, an exclusive chapter on select case histories has been added which describes the conventional and latest instruments that are being used and methods adopted for installation, monitoring and analyses of data.
