Download or read book Enhancement and Local Calibration of Mechanistic empirical Pavement Design Guide written by Hongren Gong and published by . This book was released on 2018 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mechanistic-Empirical Pavement Design Guide (MEPDG) represents the state-of-art procedure for pavement design. However, after more than a decade since its publication, the number of agencies that have reported entirely adopting this design system is small. Among the many causes of this phenomenon, the poor predictive accuracy of the performance prediction models is considered the most crucial one. To improve the accuracy of performance predicted by the MEPDG, a preliminary calibration was first conducted for these models with data from the pavement management system (PMS) of Tennessee, and then employed various machine learning algorithms for further improvements. Also, an approach for estimating the modulus of existing asphalt pavement was proposed to enhance the reliability of rehabilitation analysis with the MEPDG. The transfer functions for alligator cracking and longitudinal cracking were validated and calibrated with data collected from the PMS of the state of Tennessee. The results of calibration efforts showed that after calibration, both the bias and variance of the prediction were significantly reduced. It was noted that although local calibration helped improve the accuracy of the transfer functions, the extent of improvement is limited. An observation of the performance models revealed that they were either inadequately formulated or too inflexible to capture sufficient information from the inputs. To further improve the predictive performance of the transfer functions in the MEPDG, several machine learning algorithms were employed including the gradient boosted model (GBM) for fatigue cracking, deep neural networks for rutting, and random forest for IRI. Using the determination of coefficient (R2) and root mean squared error (RMSE) as the measure of model performance, compared with the global transfer functions, the models developed achieved significantly better predictive performance. The results from the regularized regression model indicated that, compared with the model using deflection basins parameters (DBPs), the one without DBPs could still generate modulus prediction of reasonable accuracy. Rehabilitation analyses in the MEPDG with the estimated modulus also contributed to the improved accuracy in pavement performance prediction.

Download or read book Guide for the Local Calibration of the Mechanistic empirical Pavement Design Guide written by and published by AASHTO. This book was released on 2010 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide provides guidance to calibrate the Mechanistic-Empirical Pavement Design Guide (MEPDG) software to local conditions, policies, and materials. It provides the highway community with a state-of-the-practice tool for the design of new and rehabilitated pavement structures, based on mechanistic-empirical (M-E) principles. The design procedure calculates pavement responses (stresses, strains, and deflections) and uses those responses to compute incremental damage over time. The procedure empirically relates the cumulative damage to observed pavement distresses.

Download or read book Local Calibration of Mechanistic Empirical Pavement Design Guide for North Eastern United States written by Shariq A. Momin and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mechanistic-Empirical Pavement Design Guide (MEPDG) developed under the National Cooperative Highway Research Program (NCHRP) 1-37A project is based on mechanistic-empirical analysis of the pavement structure to predict the performance of the pavement under different sets of conditions (traffic, structure and environment). MEPDG takes into account the advanced modeling concepts and pavement performance models in performing the analysis and design of pavement. The mechanistic part of the design concept relies on the application of engineering mechanics to calculate stresses, strains and deformations in the pavement structure induced by the vehicle loads. The empirical part of the concept is based on laboratory developed performance models that are calibrated with the observed distresses in the in-service pavements with known structural properties, traffic loadings, and performances. These models in the MEPDG were calibrated using a national database of pavement performance data (Long Term Pavement Performance, LTPP) and will provide design solution for pavements with a national average performance. In order to improve the performance prediction of the models and the efficiency of the design for a given state, it is necessary to calibrate it to local conditions by taking into consideration locally available materials, traffic information and the environmental conditions. The objective of this study was to calibrate the MEPDG flexible pavement performance models to local conditions of Northeastern region of United States. To achieve this, seventeen pavement sections were selected for the calibration process and the relevant data (structural, traffic, climatic and pavement performance) was obtained from the LTPP database. MEPDG software (Version 1.1) simulation runs were made using the nationally calibrated coefficients and the MEPDG predicted distresses were compared with the LTPP measured distresses (rutting, alligator and longitudinal cracking, thermal cracking and IRI). The predicted distresses showed fair agreement with the measured distresses but still significant differences were found. The difference between the measured and the predicted distresses were minimized through recalibration of the MEPDG distress models. For the permanent deformation models of each layer, a simple linear regression with no intercept was performed and a new set of model coefficients (ßr1, ßGB, and ßSG) for asphalt concrete, granular base and subgrade layer models were calculated. The calibration of alligator (bottom-up fatigue cracking) and longitudinal (topdown fatigue cracking) was done by deriving the appropriate model coefficients (C1, C2, and C4) since the fatigue damage is given in MEDPG software output. Thermal cracking model was not calibrated since the measured transverse cracking data in the LTPP database did not increase with time, as expected to increase with time. The calibration of IRI model was done by computing the model coefficients (C1, C2, C3, and C4) based on other distresses (rutting, total fatigue cracking, and transverse cracking) by performing a simple linear regression.

Download or read book Mechanistic empirical Pavement Design Guide written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 2008 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Preparation for Implementation of the Mechanistic empirical Pavement Design Guide in Michigan written by Syed Waqar Haider and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of Part 3 was to locally calibrate and validate the mechanistic-empirical pavement design guide (Pavement-ME) performance models to Michigan conditions. The local calibration of the performance models in the Pavement-ME is a challenging task, especially due to data limitations. A total of 108 and 20 reconstruct flexible and rigid pavement candidate projects, respectively, were selected. Similarly, a total of 33 and 8 rehabilitated pavement projects for flexible and rigid pavements, respectively were selected for the local calibration. The selection process considered pavement type, age, geographical location, and number of condition data collection cycles. The selected set of pavement section met the following data requirements (a) adequate number of sections for each performance model, (b) a wide range of inputs related to traffic, climate, design and material characterization, (c) a reasonable extent and occurrence of observed condition data over time. The national calibrated performance models were evaluated by using the data for the selected pavement sections. The results showed that the global models in the Pavement-ME don't adequately predict pavement performance for Michigan conditions. Therefore, local calibration of the models is essential. The local calibrations for all performance prediction models for flexible and rigid pavements were performed for multiple datasets (reconstruct, rehabilitation and a combination of both) and using robust statistical techniques (e.g. repeated split sampling and bootstrapping). The results of local calibration and validation of various models show that the locally calibrated model significantly improve the performance predictions for Michigan conditions. The local calibration coefficients for all performance models are documented in the report. The report also includes the recommendations on the most appropriate calibration coefficients for each of the performance models in Michigan along with the future guidelines and data needs.

Download or read book Local Calibration of the Mechanistic Empirical Pavement Design Guide for Kansas written by Abu Ahmed Sufian and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Kansas Department of Transportation is transitioning from adherence to the 1993 American Association of State Highway and Transportation Officials (AASHTO) Pavement Design Guide to implementation of the new AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG) for flexible and rigid pavement design. This study was initiated to calibrate MEPDG distress models for Kansas. Twenty-seven newly constructed projects were selected for flexible pavement distress model calibration, 21 of which were used for calibration and six that were selected for validation. In addition, 22 newly constructed jointed plain concrete pavements (JPCPs) were selected to calibrate rigid models; 17 of those projects were selected for calibration and five were selected for validation. AASHTOWare Pavement ME Design (ver. 2.2) software was used for design analysis, and the traditional split sampling method was followed in calibration. MEPDG-predicted distresses of Kansas road segments were compared with those from Pavement Management Information System data. Statistical analysis was performed using the Microsoft Excel statistical toolbox. The rutting and roughness models for flexible pavement were successfully calibrated with reduced bias and accepted null hypothesis. Calibration of the top-down fatigue cracking model was not satisfactory due to variability in measured data, and the bottom-up fatigue cracking model was not calibrated because measured data was unavailable. AASHTOWare software did not predict transverse cracking for any projects with global values. Thus thermal cracking model was not calibrated. The JPCP transverse joint faulting model was calibrated using sensitivity analysis and iterative runs of AASHTOWare to determine optimal coefficients that minimize bias. The IRI model was calibrated using the generalized reduced gradient nonlinear optimization technique in Microsoft Excel Solver. The transverse slab cracking model could not be calibrated due to lack of measured cracking data.

Download or read book Sensor Installation for the Local Calibration of the Mechanistic Empirical Pavement Design Guide in New Hampshire written by Matthew L. Steele and published by . This book was released on 2010 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Risk Analysis and Reliabilty Improvement of Mechanistic empirical Pavement Design written by Danny Xingqiang Xiao and published by . This book was released on 2012 with total page 544 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliability used in the Mechanistic Empirical Pavement Design Guide (MEPDG) is a congregated indicator defined as the probability that each of the key distress types and smoothness will be less than a selected critical level over the design period. For such a complex system as the MEPDG which does not have closed-form design equations, classic reliability methods are not applicable. A robust reliability analysis can rely on Monte Carlo Simulation (MCS). The ultimate goal of this study was to improve the reliability model of the MEPDG using surrogate modeling techniques and Monte Carlo simulation. To achieve this goal, four tasks were accomplished in this research. First, local calibration using 38 pavement sections was completed to reduce the system bias and dispersion of the nationally calibrated MEPDG. Second, uncertainty and risk in the MEPDG were identified using Hierarchical Holographic Modeling (HHM). To determine the critical factors affecting pavement performance, this study applied not only the traditional sensitivity analysis method but also the risk assessment method using the Analytic Hierarchy Process (AHP). Third, response surface models were built to provide a rapid solution of distress prediction for alligator cracking, rutting and smoothness. Fourth, a new reliability model based on Monte Carlo Simulation was proposed. Using surrogate models, 10,000 Monte Carlo simulations were calculated in minutes to develop the output ensemble, on which the predicted distresses at any reliability level were readily available. The method including all data and algorithms was packed in a user friendly software tool named ReliME. Comparison between the AASHTO 1993 Guide, the MEPDG and ReliME was presented in three case studies. It was found that the smoothness model in MEPDG had an extremely high level of variation. The product from this study was a consistent reliability model specific to local conditions, construction practices and specifications. This framework also presented the feasibility of adopting Monte Carlo Simulation for reliability analysis in future mechanistic empirical pavement design software.

Download or read book Using Multi objective Optimization to Enhance Calibration of Performance Models in the Mechanistic Empirical Pavement Design Guide written by Nima Kargah-Ostadi and published by . This book was released on 2018 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research study devised two scenarios for application of multi-objective optimization to enhance calibration of performance models in the American Association of State Highway and Transportation Officials (AASHTO) AASHTOWare® Pavement ME Design software.(1) In the primary scenario, mean and standard deviation of prediction error are simultaneously minimized to increase accuracy and precision at the same time. In the second scenario, model prediction error on data from Federal Highway Administration’s Long-Term Pavement Performance test sections and error on available accelerated pavement testing data are treated as independent objective functions to be minimized simultaneously. The multi-objective optimization results in a final pool of tradeoff solutions, where none of the viable sets of calibration factors are eliminated prematurely. Exploring the final front results in more reasonable calibration coefficients that could not be identified using single-objective approaches. This report demonstrates the application of engineering judgment and qualitative criteria to select reasonable calibration coefficients from the final pool of solutions that result from the multi-objective optimization. More reasonable calibration factors result in a more justifiable pavement design considering multiple aspects of pavement performance. This investigation revealed that simply evaluating the bias and standard error is not adequate for a comprehensive evaluation of performance prediction models.

Download or read book Calibration and Validation of the Enhanced Integrated Climatic Model for Pavement Design written by C. E. Zapata and published by Transportation Research Board National Research. This book was released on 2008 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This report summarizes the results of research to evaluate, calibrate, and validate the Enhanced Integrated Climatic Model (EICM) incorporated in the original Version 0.7 (July 2004 release) of the Mechanistic-Empirical Pavement Design Guide (MEPDG) software with measured materials data from the Long-Term Pavement Performance Seasonal Monitoring Program (LTPP SMP) pavement sections. The report further describes subsequent changes made to the EICM to improve its prediction of moisture equilibrium for granular bases. The report will be of particular interest to pavement design engineers in state highway agencies and industry ..."--Foreword.

Download or read book Calibration of the Mechanistic empirical Pavement Design Guide for Local Paved Roads in Wyoming written by Taylor J. Kasperick and published by . This book was released on 2013 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mechanistic-Empirical Pavement Design Guide (MEPDG) was released in 2004 under NCHRP Project 1-37A. Since that time, considerable efforts to calibrate the program and its performance prediction models for local conditions have taken place in multiple states attempting to implement the program. Currently, Wyoming DOT is in the process of implementing the DARWIN-ME (the MEPDG in its most current form) on the interstate and the state highway systems. In order to compliment that effort, this study attempted to develop a set of calibration coefficients and localized traffic inputs that can be used on local paved roads. Wyoming is an energy rich state and has seen an increase in the amount of heavy truck traffic that its roadways encounter, thus requiring locally calibrated inputs for the DARWIN-ME. Predicted distresses using the DARWIN-ME were largely different from measured distresses on local paved roadways included in this study, particularly IRI, rutting, alligator cracking, transverse cracking, and longitudinal cracking. These distresses were measured on the local paved roads using Pathway Services Inc. and the surface imaging that it provided. Inputs for trial runs using the DARWIN-ME were determined through work with local county road maintenance superintendents, WYDOT, and previous research regarding climatic data in Wyoming. Localized traffic inputs were developed using Weigh-In Motion (WIM) data collected on non-interstate roadways across Wyoming. Once a significant error and bias were found between predicted and measured distresses, calibration coefficients for IRI, alligator cracking, rutting, and longitudinal cracking were altered to reduce bias and sum of squared errors. The final calibration coefficients settled on in this study reduced the sum of squared errors and bias significantly. A sensitivity analysis was also performed during this study to determine the effect of layer thicknesses on the prediction capabilities of the DARWIN-ME. The process followed in this study can be utilized by other local governments around the country to help them implement the DARWIN-ME.

Download or read book Development of Local Calibration Factors and Design Criteria Values for Mechanistic empirical Pavement Design written by Bryan Smith and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A mechanistic-empirical (ME) pavement design procedure allows for analyzing and selecting pavement structures based on predicted distress progression resulting from stresses and strains within the pavement over its design life. The Virginia Department of Transportation (VDOT) has been working toward implementing ME design by characterizing traffic and materials inputs, training with the models and design software, and analyzing current pavement designs in AASHTOware Pavement ME Design software. This study compared the measured performance of asphalt and continuously reinforced concrete pavements (CRCP) from VDOTs Pavement Management System (PMS) records to the predicted performance in AASHTOware Pavement ME Design. Model coefficients in the software were adjusted to match the predicted asphalt pavement permanent deformation, asphalt bottom-up fatigue cracking, and CRCP punchout outputs to the measured values from PMS records. Values for reliability, design life inputs, and distress limits were identified as a starting point for VDOT to consider when using AASHTOware Pavement ME Design through consideration of national guidelines, existing VDOT standards, PMS rating formulas, typical pavement performance at time of overlay, and the data used for local calibration. The model calibration coefficients and design requirement values recommended in this study can be used by VDOT with AASHTOware Pavement ME Design as a starting point to implement the software for design, which should allow for more optimized pavement structures and improve the long-term performance of pavements in Virginia.

Download or read book Guide for the Local Calibration of the Mechanistic empirical Pavement Desing Guide written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Draft User s Guide for UDOT Mechanistic empirical Pavement Design written by Michael I. Darter and published by . This book was released on 2009 with total page 136 pages. Available in PDF, EPUB and Kindle. Book excerpt: Validation of the new AASHTO Mechanistic-Empirical Pavement Design Guide's (MEPDG) nationally calibrated pavement distress and smoothness prediction models when applied under Utah conditions, and local calibration of the new hot-mix asphalt (HMA) pavement total rutting model, were recently completed as documented in UDOT Research Report No. UT-09.11 Implementation of the Mechanistic-Empirical Pavement Design Guide in Utah: Validation, Calibration, and Development of the UDOT MEPDG User's Guide, dated October 2009. This Draft User's Guide incorporates the findings of the model validation and local calibration report and provides information for use by UDOT's pavement design engineers during trial implementation of the MEPDG. This information includes an overview of the MEPDG procedure, information on installation of the software, guidelines for obtaining all needed inputs, guidance to perform pavement design using the software for new and rehabilitated HMA pavement and jointed plain concrete pavement (JPCP), and pavement design examples for new HMA pavement and new JPCP using the MEPDG software.

Download or read book Rigid Pavement written by Jian Zhong and published by . This book was released on 2017 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Mechanistic-Empirical Pavement Design Guide (MEPDG) has been introduced to transportation agencies as an innovative method for analysis and design of pavements. However, the MEPDG cannot be used by highway agencies without calibration due to the different situations in Canada. Local calibration the MEPDG, which means adjusting the coefficients of performance prediction models to meet the local conditions, should be an essential step for any agencies before the official acceptation of the MEPDG. As the part of the project, Local Calibration of the MEPDG Prediction Models Using More Accurate Field Measurements funded by Highway Infrastructure Innovation Funding Program (HIIFP), this research involved the local calibration of the models for Jointed Plain Concrete Pavement (JPCP) in the Province of Ontario. Using the field measurements collected by Ministry of Transportation in Ontario (MTO), the study performed local calibration for 32 rigid (JPCP) pavement sections. The primary objective of this study was to examine prediction results using global models; then if not agree with the measurements, refine the coefficients of the MEPDG performance models using the nonlinear optimization methods. The proposed calibration was applied by using the sections located in different zones throughout Ontario to represent the local features, including climate and traffic conditions. Finally, the local calibration results are presented and compared with previous results of global models to assess the robustness of local calibration. The research shows the feasibility of the mathematical optimization method for in local calibration in Ontario, and it also provides some useful findings for future uses of the MEPDG.

Download or read book Local Calibration of the MEPDG for Flexible Pavement Design written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The 1993 American Association of State Highway and Transportation Officials (AASHTO) Guide for Design of Pavement Structures is a mere modification of the empirical methods found in its earlier versions that are based on regression equations relating simple material and traffic inputs. Although the various editions of the AASHTO design guide have served well for several decades, they contain too many limitations to be continued as the nation's primary pavement design procedures. The Mechanistic-Empirical Pavement Design Guide (MEPDG) procedure, on the other hand, provides the tools for evaluating the effect of variations in input data on pavement performance. The design method in the MEPDG is mechanistic because it uses stresses and strains in a pavement system calculated from the pavement response model to predict the performance of the pavement. The empirical nature of the design method stems from the fact that the pavement performance predicted from laboratory-developed performance models is adjusted based on the observed performance from the field to reflect the differences between predicted and actual field performance. The performance models used in the MEPDG are calibrated using limited national databases and, thus, it is necessary to calibrate these models for local highway agencies implementation by taking into account local materials, traffic information, and environmental conditions. Two distress models, permanent deformation and bottom-up fatigue cracking (hereafter referred to as alligator cracking), were employed for this effort. Fifty-three pavement sections were selected for the calibration and validation process: 30 long-term pavement performance (LTPP) pavements, which include 16 new flexible pavement sections and 14 rehabilitated sections, and 23 North Carolina Department of Transportation (NCDOT) sections. All the necessary data were obtained from the LTPP and the NCDOT databases. To provide reasonable values in cases where data were missing, MEP.

Download or read book Local Calibration of the MEPDG for Flexible Pavement Design written by Y. Richard Kim and published by . This book was released on 2011 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: In an effort to move toward pavement designs that employ mechanistic principles, the AASHTO Joint Task Force on Pavements initiated an effort in 1996 to develop an improved pavement design guide. The project called for the development of a design guide that employs existing state-of-the-practice mechanistic-based models and design procedures. The product of this initiative became available in 2004 in the form of software called the Mechanistic-Empirical Pavement Design Guide (MEPDG). The performance prediction models in the MEPDG were calibrated and validated using performance data measured from hundreds of pavement sections across the United States. However, these nationally calibrated performance models in the MEPDG do not necessarily reflect local materials, local construction practices, and local traffic characteristics. Therefore, in order to produce accurate pavement designs for the State of North Carolina, the MEPDG distress prediction models must be recalibrated using local materials, traffic, and environmental data. The North Carolina Department of Transportation (NCDOT) has decided to adopt the MEPDG for future pavement design work and has awarded a series of research projects to North Carolina State University. The primary objective of this study is to calibrate the MEPDG performance prediction models for local materials and conditions using the data and findings generated from this series of research projects. The work presented in this report focuses on four major topics: (1) the development of a GIS-based methodology to enable the extraction of local subgrade soils data from a national soils database; (2) the rutting and fatigue cracking performance characterization of twelve asphalt mixtures commonly used in North Carolina; (3) the characterization of local North Carolina traffic; and (4) calibration of the flexible pavement distress prediction models in the MEPDG to reflect local materials and conditions.