Download or read book Estimation of Subgrade Resilient Modulus Using the Unconfined Compression Test written by Shabbir M. Hossain and published by . This book was released on 2014 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: To facilitate pavement design, the new proposed mechanistic-empirical pavement design guide recommends the resilient modulus to characterize subgrade soil and its use for calculating pavement responses attributable to traffic and environmental loading. Although resilient modulus values could be determined through laboratory testing of actual subgrade soil samples, such testing would require significant resources including a high level of technical capability to conduct the test and interpret results. For smaller or less critical projects, where costly and complex resilient modulus testing is not justified, correlation with the results of other simpler tests could be used. The Virginia Department of Transportation (VDOT) uses a simple correlation with the California bearing ratio (CBR) to estimate the resilient modulus in their current pavement design procedure in accordance with the 1993 AASHTO design guide. As this correlation with CBR is considered to be poor, a simpler unconfined compression (UC) test was explored for better estimation of the resilient modulus of fine-grained soils. Several models were developed in this study to estimate the resilient modulus of fine-grained soil from the results of UC tests. The simplest model considers only the UC strength to predict the resilient modulus with a fair correlation. The more detailed models with stronger correlations also consider the plasticity index, percentage of materials passing the No. 200 sieve, and modulus of the stress-strain curve from the UC test. These models are recommended for implementation by VDOT

Download or read book Estimating Stiffness of Subgrade and Unbound Materials for Pavement Design written by Anand J. Puppala and published by Transportation Research Board. This book was released on 2008 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: At head of title: National Cooperative Highway Research Program.

Download or read book Resilient Modulus Testing for Pavement Components written by Mary Stroup-Gardiner and published by ASTM International. This book was released on 2003 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Resilient modulus indicates the stiffness of a soil under controlled confinement conditions and repeated loading. The test is intended to simulate the stress conditions that occur in the base and subgrade of a pavement system. Resilient modulus has been adopted by the U.S. federal highway administration as the primary performance parameter for pavement design. We thank those who prepared these papers, the reviewers who provided anonymous peer reviews, and those who participated in the symposium. We hope this STP encourages more work to improve the testing standard and the value of the Resilient Modulus test."

Download or read book Characterization of Unbound Pavement Materials from Virginia Sources for Use in the New Mechanistic empirical Pavement Design Procedure written by M. Shabbir Hossain and published by . This book was released on 2010 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The implementation of mechanistic-empirical pavement design requires mechanistic characterization of pavement layer materials. The subgrade and base materials are used as unbound, and their characterization for Virginia sources was considered in this study as a supplement to a previous study by the Virginia Transportation Research Council. Resilient modulus tests were performed in accordance with AASHTO T 307 on fine and coarse soils along with base aggregates used in Virginia. The degree of saturation as determined by moisture content and density has shown significant influence on the resilient behavior of these unbound materials. The resilient modulus values, or k-values, are presented as reference for use by the Virginia Department of Transportation (VDOT). The results of other tests were analyzed for correlation with the results of the resilient modulus test to determine their use in estimating resilient modulus values. The results of the triaxial compression test, referred to as the quick shear test in AASHTO T 307, correlated favorably with the resilient modulus. Although the complexity of such a test is similar to that of the resilient modulus test for cohesionless coarse soil and base aggregate, fine cohesive soil can be tested with a simpler triaxial test: the unconfined compression test. In this study, a model was developed to estimate the resilient modulus of fine soil from the initial tangent modulus produced on a stress-strain diagram from an unconfined compression test. The following recommendations are made to VDOT's Materials Division: (1) implement the use of the resilient modulus test for pavement design along with the implementation of the MEPDG; (2) use the universal constitutive model recommended by the MEPDG to generate the k-values needed as input to MEPDG Level 1 design/analysis for resilient modulus calculation; (3) develop a database of resilient modulus values (or k-values), which could be used in MEPDG design/analysis if a reasonable material match were to be found; (4) use the initial tangent modulus from an unconfined compression test to predict the resilient modulus values of fine soils for MEPDG Level 2 input and the 1993 AASHTO design; and (5) continue to collect data for the unconfined compression test and update the prediction model for fine soil in collaboration with the Virginia Transportation Research Council. Implementing these recommendations would support and expedite the implementation efforts under way by VDOT to initiate the statewide use of the MEPDG. The use of the MEPDG is expected to improve VDOT's pavement design capability and should allow VDOT to design pavements with a longer service life and fewer maintenance needs and to predict maintenance and rehabilitation needs more accurately over the life of the pavement.

Download or read book Monitoring and Evaluation of Fly Ash Stabilization Stabilized Subgrade Constructed by the WisDOT written by Tuncer Edil and published by . This book was released on 2010 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laboratory Determination of Resilient Modulus of Missouri Subgrade Soils written by and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Resilient Modulus of Soils and Soil Cement Mixtures written by TP. Trindade and published by . This book was released on 2003 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Knowledge of the resilient modulus (MR) of the sub-grade soils and materials that compose the layers of road pavements is mandatory for an efficient analysis of their structural behavior as a whole. However, laboratory determination of MR requires employment of relatively sophisticated loading systems and data acquisition, besides demanding considerable testing time. Therefore, it is desirable to look for standard test methods that can be used to estimate this engineering parameter. This paper presents geotechnical engineering parameters of two soils and their soil-cement mixtures, and provides empirical correlations between CBR, unconfined compression strength determined at 1% of axial strain, Young's tangent modulus, and measured values of MR of these soils and mixtures.

Download or read book Alternative Test Method for Resilient Modulus of Fine Grained Subgrades written by EC. Drumm and published by . This book was released on 1996 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The mechanistic design of flexible pavement systems requires the specification of mechanical properties for asphaltic concrete, base course, and soil subgrade. The stiffness of the soil subgrade is represented by the resilient modulus, Mr, which is determined in the laboratory from cyclic triaxial tests and is usually a function of the level of applied stress. For a typical pavement project where numerous soils are encountered, cyclic triaxial testing to determine Mr for each subgrade soil may be too complex and time consuming to be applicable on a production basis. Therefore, alternative methods for the determination or estimation of Mr are appropriate and are in fact suggested in the 1993 AASHTO Guide for Design of Pavement Structures (AASHTO Guide 1993).

Download or read book Novel Issues on Unsaturated Soil Mechanics and Rock Engineering written by Laureano R. Hoyos and published by Springer. This book was released on 2018-10-29 with total page 243 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume discusses issues related to unsaturated soil mechanics and rock engineering based on technical papers focusing on two important topics in geotechnical engineering: (1) the characterization of unsaturated soils, and (2) the investigation of rock properties. The research studies on unsaturated soils include the characterization techniques of the unsaturated soils. The studies on rock properties include thermo-hydro-mechanical behavior of gypsum rock, soft rocks capacity, role of rock strength in blastability, indirect methods to estimate rock strength, and variations in isotope distributions in Permian rocks. The two broad themes in this collection, as summarized above, are representative of local challenges facing geotechnical engineers in the Middle East, but their contributions can also be extended to other regions of the world. The volume is based on the best contributions to the 2nd GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2018 – The official international congress of the Soil-Structure Interaction Group in Egypt (SSIGE).

Download or read book Investigation of DCP and SSG as Alternative Methods to Determine Subgrade Stability written by Tuncer B. Edil and published by . This book was released on 2005 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bearing Capacity Of Roads Volume 2 written by A. Gomes Correia and published by CRC Press. This book was released on 2020-12-18 with total page 730 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an outcome of the sixth conference on bearing capacity of roads and airfield held in Lisbon, Portugal. It covers the following topics: bearing capacity policies, concepts, costs and condition surveys; analysis and modelling; design and environmental effects; and asphalt mixtures.

Download or read book Summary of Lessons Learned from the MDOT MEPDG Materials Library Study written by Robert S. James and published by . This book was released on 2010 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Role of Coarse Soil Fraction on Resilient Moduli Properties of Clayey Soil written by Chatuphat Savigamin and published by . This book was released on 2014 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: As one of the major methods of soil stabilization used in the present, mechanical stabilization improves a native soil by admixing a coarse and/or fine material. This method of soil stabilization aims to reach a composition in which coarser particles form the skeleton and the surrounding space is filled with fine grains. As a result, higher soil strength can be achieved. To study the soil strength improvement behavior, resilient modulus and unconfined compressive strength are used as evaluation parameters in this research. Since the present research focuses on subgrade soils, Dallas clay was selected as a reference clayey soil representing a native subgrade. Industrial silica sand was an admixing material. Six types of clay-sand mixtures were prepared from Dallas clay with 0%, 5%, 10%, 20%, 30%, and 50% sand admixture, respectively. Unconfined compression tests and resilient modulus tests were performed on six types of the clay-sand mixtures. The preparation of the test samples was adhered to their maximum dry density and optimum moisture content obtained from Proctor tests. The unconfined compression test results showed that unconfined compressive strength linearly increased with an increase in the sand admixture. For the resilient modulus (MR) tests, the measured MR results were analyzed with the universal model in order to determine the predicted MR results, which were found to be well matched with the measured results. Based on both measured and predicted MR results, the turning point of the clay-sand mixture from a stress-softening to stress hardening material was exhibited when the percentage of the sand admixture was increased to 10%. Both deviatoric stress and confining pressure are also found to have a significant effect on the resilient modulus. In addition, the resilient modulus (MR) improvement analysis showed that the MR significantly increased when the amount of the sand admixture was increased. The threshold of the effective resilient modulus improvement was also found at Dallas clay with 10% sand admixture.

Download or read book Geotechnical Abstracts written by and published by . This book was released on 1992 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Field Performance of Sub bases Constructed with Industrial Byproducts and Geosynthetic Reinforcement written by and published by . This book was released on 2005 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Strain Controlled Testing for Subgrade Resilient Modulus written by Eleazar Montemayor and published by . This book was released on 1995 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soil Testing Soil Stability and Ground Improvement written by Wissem Frikha and published by Springer. This book was released on 2017-07-11 with total page 421 pages. Available in PDF, EPUB and Kindle. Book excerpt: Earthwork projects are critical components in civil construction and often require detailed management techniques and unique solution methods to address failures. Being earth bound, earthwork is influenced by geomaterial properties at the onset of a project. Hence, an understanding of the in-situ soil properties is essential. Slope stability is a common problem facing earthwork construction, such as excavations and shored structures. Analytical methods for slope stability remain critical for researchers due to the mechanical complexity of the system. Striving for better earthwork project managements, the geotechnical engineering community continues to find improved testing techniques for determining sensitive properties of soil and rock, including stress-wave based, non-destructive testing methods. To minimize failure during earthwork construction, past case studies and data may reveal useful lessons and information to improve project management and minimize economic losses. This volume is part of the proceedings of the 1st GeoMEast International Congress and Exhibition on Sustainable Civil Infrastructures, Egypt 2017.