Systematic back-calculation protocol and prediction of resilient modulus for MEPDG
- 21 March 2016
- journal article
- research article
- Published by Taylor & Francis Ltd in International Journal of Pavement Engineering
- Vol. 19 (1), 62-74
- https://doi.org/10.1080/10298436.2016.1162303
Abstract
A research focusing on the characterisation of representative local material properties was conducted to facilitate the full implementation of the Mechanistic-Empirical Pavement Design Guide for roadway designs in Wyoming. As part of the test program, falling weight deflectometer deflection data were collected from 25 test sites in Wyoming for back-calculation of subgrade resilient modulus. Also, subgrade materials from these test sites were sampled for laboratory resilient modulus measurement in accordance with the AASHTO T 307. The back-calculation is a user-dependent procedure and produces a non-unique resilient modulus estimation. To alleviate this limitation, this paper focuses on the recent development of a systematic back-calculation protocol for subgrade resilient modulus using MODCOMP6 software. The protocol is intended for use on a flexible pavement with a crushed base. The proposed procedure discusses pre-analysis checks, seed modulus adjustment, pavement structure adjustment and program termination criteria. A correlation study was conducted to correct back-calculated resilient modulus to laboratory-equivalent values. The results conclude that a non-zero intercept linear regression model provides a better correlation than the widely used zero intercept linear regression model. Furthermore, better correlations are achieved when the back-calculated resilient modulus of a lower subgrade layer and resilient modulus measured at higher laboratory test sequences Nos. 11 to 15 are considered. The non-zero model based on Mr test sequence No. 14 and lower subgrade layer yields the best correlation. For the zero model, a C-factor of 0.645 based on Mr test sequence No. 15 and lower subgrade layer yields the best correlation.Keywords
This publication has 16 references indexed in Scilit:
- Comparison of resilient modulus values for Florida flexible mechanistic-empirical pavement designInternational Journal of Pavement Engineering, 2012
- Backcalculation of pavement layer moduli and Poisson’s ratio using data miningExpert Systems with Applications, 2011
- Estimation of Resilient Modulus of Subgrade Soils Using Falling Weight DeflectometerTransportation Research Record: Journal of the Transportation Research Board, 2010
- Evaluation of layer properties of flexible pavement using a pseudo-static analysis procedure of Falling Weight DeflectometerConstruction and Building Materials, 2009
- Backcalculated and Laboratory-Measured Resilient Modulus ValuesTransportation Research Record: Journal of the Transportation Research Board, 2009
- Advances in backcalculating the mechanical properties of flexible pavementsAdvances in Engineering Software, 2006
- Seed Modulus Generation Algorithm for Backcalculation of Flexible Pavement ModuliTransportation Research Record: Journal of the Transportation Research Board, 2005
- Evaluation of FWD Data for Determination of Layer Moduli of PavementsJournal of Materials in Civil Engineering, 2003
- Falling Weight Deflectometer for Estimating Subgrade Elastic ModuliJournal of Transportation Engineering, 2003
- Time Domain Backcalculation of Pavement Structure Material Properties Using 3D FEM with Ritz VectorsInternational Journal of Geomechanics, 2001