Download or read book Pavement subgrade Material Characterization and Advanced Computer Simulations written by Yamini Varma Nanagiri and published by . This book was released on 2001 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiscale Characterization of Advanced Pavement Materials written by Dawei Wang and published by Frontiers Media SA. This book was released on 2023-10-20 with total page 133 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced characterisation of pavement and soil engineering materials written by International Conference on Advanced Characterisation of Pavement and Soil Engineering Materials and published by . This book was released on 2007 with total page 1859 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pavements and Materials written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Advances in Materials Characterization and Modeling of Pavement Systems written by E. Tutumluer and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: GSP 123 contains 16 technical papers covering recent advances in the characterization and modeling of materials used in pavement systems presented at the Pavement Mechanics Symposium at the 15th ASCE Engineering Mechanics Conference, held in New York, New York, June 4, 2002.

Download or read book Pavements and Materials Characterization Modeling and Simulation written by Ala R. Abbas and published by ASCE Publications. This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Recent Advances in Materials Characterization and Modeling of Pavement Systems written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Characterisation of Pavement and Soil Engineering Materials written by Andreas Loizos and published by Taylor & Francis Group. This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Effect of Subgrade Conditions on Pavement Analysis and Performance Prediction written by Md Jibon and published by . This book was released on 2019 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: "The Mechanistic-Empirical (M-E) pavement design approach detailed in the Mechanistic-Empirical Pavement Design Guide (MEPDG), and subsequently implemented through AASHTOWare® Pavement ME Design relies extensively on detailed material properties that ultimately govern the analysis and performance prediction results. For unbound materials like soils and aggregates, Resilient Modulus (MR) is the most critical input parameter affecting layer response under vehicular and environmental loading. Representing a material’s ability to ‘recover’ after loading, resilient modulus is determined in the laboratory through repeated load triaxial testing. Although the original test protocol to measure the resilient modulus value of a soil or aggregate was developed back in the 1980’s, this test is still not widely used by state highway agencies because it is cumbersome, and requires significant investments towards equipment and personnel training. Accordingly, most agencies rely on correlation equations to predict the resilient modulus values for soils and aggregates from other easy-to-determine material properties. However, these correlation equations are mostly region specific, and therefore, do not produce adequate results across different geographic regions. This has led several state highway agencies to undertake local calibration efforts for improved prediction of material properties. Over the past decade, the Idaho Transportation Department (ITD) has invested significant resources to facilitate state-wide implementation of mechanistic-empirical pavement design practices. A research study was recently undertaken by ITD to develop a database of resilient modulus properties for different soils and aggregates commonly used in the state of Idaho for pavement applications. Another objective of the study was to assess the adequacy of different correlation equations currently available to predict soil and aggregate resilient modulus from easy-to-determine material (strength and index) properties. This Master’s thesis is based on tasks carried out under the scope of the above-mentioned project, and focuses on laboratory characterization and analysis of representative subgrade soil types collected from across Idaho. An extensive laboratory test matrix was developed involving commonly used mechanical and index tests, repeated load triaxial tests for resilient modulus determination, as well as tests to study the soil permanent deformation (plastic strain) behavior. Effect of moisture variation on soil strength, modulus, and permanent deformation properties was also studied by testing soil specimens at three different moisture contents. The test results were thoroughly analyzed to evaluate the feasibility of predicting resilient modulus from other material properties. Findings from this research effort have been documented in the form of two journal manuscripts. The first manuscript highlights the importance of using adequate subgrade resilient modulus values during pavement design. Eight different soil types were randomly selected from a total of sixteen soil types, and the corresponding laboratory test results were used to highlight the limitations of ITD’s current approach with assumed resilient modulus values. The second manuscript focuses on highlighting the importance of unbound material permanent deformation characterization during pavement design, and how small changes in moisture content can lead to significant differences in the rutting behavior of subgrade soils. First, a new permanent deformation testing protocol was developed to simulate typical stress states experienced by subgrade layers under vehicular loading. Subsequently, permanent deformation tests were carried out on subgrade soil types collected from two distinctly different regions in Idaho as far as annual precipitation is concerned. Tests were conducted at three different moisture contents to highlight how the rutting potential of the subgrade may change significantly based on site precipitation and drainage characteristics. Finally, recommendations were made regarding how state highway agencies can accurately represent resilient modulus properties of soils during pavement analysis and performance prediction using AASHTOWare® Pavement ME Design."--Boise State University ScholarWorks.

Download or read book Laboratory Characterization of Cohesive Subgrade Materials written by Mohammad Ali Khasawneh and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "When designing pavements, there are three fundamental external design parameters to evaluate (1) the characteristics of the subgrade upon which the pavement is placed, (2) the applied loads, and (3) the environment. The subgrade layer, upon which the pavement is constructed, will have a large impact on structural design. The study was based on extensive laboratory work to characterize cohesive subgrade materials. Permeability of the subgrade was obtained using a flexible wall permeameter, which simulates the actual field conditions. The factors affecting permeability were also discussed. Strength parameters were determined utilizing the static load triaxial apparatus. The Consolidated-Undrained Triaxial Compression Test and Unconfined Compression Test were performed. Resilient modulus testing was conducted using a repeated load triaxial system at different confining pressures employing AASHTO T294-92I. A new testing procedure, stage loading, was used to test the permanent deformation of subgrade materials at different stress levels and load repetitions; this technique allows researchers to explore the effect of stress history on the accumulation of plastic deformation besides saving time, effort, and test specimens. Hydraulic conductivity results showed a practically impermeable subgrade layer. From the measured data of the consolidation test, the pressure-void ratio relationship was plotted and used in determining the compression index, recompression index and maximum past pressure of the soil. In addition, the coefficients of consolidation were obtained. Mohr circles at failure and Mohr failure envelopes were drawn for the total and effective stress data obtained from the CU tests, from which shear strength parameters were determined. On the other hand, Mohr circles at failure were drawn for the unconfined compression test that indicated the cohesive subgrade soils to vary between very stiff and hard consistency. Furthermore, isotropic elasticity analysis was carried out. It was found that soil moduli increase as the confining pressure increases according to the elastic theory. Resilient modulus results showed a slight increase in resilient modulus value with an increase in confining pressure. The permanent deformation results showed a constant increasing rate of plastic strain at higher stress levels. The results obtained will be added to the ODOT database to help engineers in characterizing the cohesive subgrade materials."--Page iii-iv.

Download or read book Local Calibration of Material Characterization Models for Performance based Flexible Pavement Design written by Alexander Afuberoh and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mechanistic Empirical Pavement Design Guide (MEPDG) method, currently known as Pavement ME, recommends using locally calibrated material characterization models developed from laboratory testing of local materials under specific environmental and traffic loading conditions. The Pavement ME design method offers a more realistic design procedure and reduces the uncertainty that arise from empirical design procedures. This thesis developed a locally calibrated indirect tensile (IDT) strength material model for low temperature cracking predictions of hot mix asphalt (HMA) in Manitoba, Canada. In addition, the research investigated the integration of locally calibrated HMA, and unbound granular material characterization models into the Pavement ME framework to improve the design of flexible pavements. Laboratory IDT testing was conducted on typical HMA mixtures containing extracted binders and varying percentages of reclaimed asphalt pavement (RAP). The laboratory measured IDT strengths were used to calibrate a local IDT strength predictive model for Manitoba. The predictions from the local Manitoba model were compared to the predictions from the global Pavement ME IDT model, and a Michigan calibrated IDT model, using a statistical analysis. It was found that the global Pavement ME IDT strength model, if used without local calibration, produced inaccurate predictions of the IDT strength for Manitoba mixtures. It was also found that binder characterization methods in Level 2 and Level 3 can significantly impact the accuracy of IDT strength predictions. A case study using developed local HMA, base, and subgrade material characterization models in Manitoba were compared to designs using default (Level 3) material input values in Pavement ME design software. The results of integrating the locally calibrated models for HMA, base and subgrade layers demonstrated that the locally calibrated materials model inputs produce lower pavement structural thicknesses with higher reliability in the predicted distresses when compared to the default materials inputs. The effect of using calibrated material inputs was more pronounced for higher traffic loadings. The results of the study demonstrate that the use of calibrated models can potentially produce optimized pavement thicknesses due to improved pavement designs.

Download or read book Recent Advances in Materials Characterization and Modeling of Pavement Systems written by E. Tutumluer and published by . This book was released on 2004 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Long and Deep Tunnels written by Vittorio Guglielmetti and published by CRC Press. This book was released on 2016-04-15 with total page 1336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design and construction of “long and deep” tunnels, i.e. tunnels under mountains, characterised by either considerable length and/or overburden, represent a considerable challenge. The scope of this book is not to instruct how to design and construct such tunnels but to share a method to identify the potential hazards related to the process of designing and constructing long and deep tunnels, to produce a relevant comprehensive analysis and listing, to quantify the probability and consequences, and to design proper mitigation measures and countermeasures. The design, developed using probabilistic methods, is verified during execution by means of the so called Plan for Advance of the Tunnel (PAT) method, which allows adapting the design and control parameters of the future stretches of the tunnel to the results of the stretches already finished, using the monitoring data base. Numerous criteria are given to identify the key parameters, necessary for the PAT procedure. Best practices of excavation management with the help of real time monitoring and control are also provided. Furthermore cost and time evaluation systems are analysed. Finally, contractual aspects related to construction by contract are investigated, for best development and application of models more appropriate for tunnelling-construction contracts. The work will be of interest to practising engineers, designers, consultants and students in mining, underground, tunnelling, transportation and construction engineering, as well as to foundation and geological engineers, urban planners/developers and architects.

Download or read book Advanced Research on Computer Education Simulation and Modeling written by Sally Lin and published by Springer Science & Business Media. This book was released on 2011-06-06 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume set (CCIS 175 and CCIS 176) constitutes the refereed proceedings of the International Conference on Computer Education, Simulation and Modeling, CSEM 2011, held in Wuhan, China, in June 2011. The 148 revised full papers presented in both volumes were carefully reviewed and selected from a large number of submissions. The papers cover issues such as multimedia and its application, robotization and automation, mechatronics, computer education, modern education research, control systems, data mining, knowledge management, image processing, communication software, database technology, artificial intelligence, computational intelligence, simulation and modeling, agent based simulation, biomedical visualization, device simulation & modeling, object-oriented simulation, Web and security visualization, vision and visualization, coupling dynamic modeling theory, discretization method , and modeling method research.

Download or read book Airport Facilities written by Michael T. McNerney and published by . This book was released on 1998 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thirty-nine papers from a June 1998 conference include development track presentations from planners involved with Dallas/Ft. Worth, Salt Lake City, Los Angeles, and metropolitan Washington airports. Coverage includes current issues in planning, design, and construction, with much discussion of vari

Download or read book Computer Methods and Advances in Geomechanics written by Chandra S. Desai and published by Taylor & Francis US. This book was released on 1991 with total page 1008 pages. Available in PDF, EPUB and Kindle. Book excerpt: