Sage Journals: Discover world-class research

Abstract

Site 1 in Hanover, New Hampshire, is a test section with surface deflection, stress, and strain measurements. The data are used to perform linear and nonlinear backcalculation of pavement layer moduli and material parameters from the deflection bowls. The data show clearly that the pavement response is nonlinear and the following trends are observed: (a) the base material stiffens relative to the subgrade as the load increases and (b) the upper subgrade becomes softer as the load increases. The procedures and material characterization for linear and nonlinear analyses are presented. The nonlinear one uses an axisymmetric finite element program to compute displacements, stresses, and strains. The results of the backcalculation (using deflection bowls only) show better fit of the surface deflections with the nonlinear than with the linear approach. The linear procedure seems to introduce a systematic error in the fit. The nonlinear approach predicts a distribution of moduli in the structure that is acceptable from an engineering point of view. With the parameters obtained from backcalculation, displacements and stresses are computed and compared with the measured ones. It seems that the computed response differs from the measured one by a factor of about 1.5. The prediction of stresses and strains is slightly better with the nonlinear than with the linear procedure.

Get full access to this article

View all access options for this article.

References

Uzan

Advanced Backcalculation Techniques, Second International Symposium on Nondestructive Testing of Pavements and Backcalculation of Moduli, June 1993, Atlanta, ASTM Special Technical Publication 1198, 1994, pp. 3–37.

Uzan

, Scullion

, Michalek

C. H.

, Parades

, and Lytton

R. L.

. A Microcomputer Based Procedure for Backcalculating Layer Moduli from FWD Data. Report FHWA/TX-88-1123-1. Texas Transportation Institute, Sept. 1988, p. 82.

Uzan

Dynamic Linear Backcalculation of Pavement Material Parameters for Flexible Pavements. ASCE Journal of Transportation Engineering, Vol. 120, No. 1, 1994, pp. 109–126.

Van Cauwelaert

F. J.

, Alexander

D. R.

, White

T. D.

, and Barker

W. R.

. Multilayer Elastic Program for Backcalculating Layer Moduli in Pavement Evaluation, ASTM Special Technical Publication 1026, 1989, pp. 171–188.

Uzan

Influence of the Interface Condition on Stress Distribution in a Layered System. In Transportation Research Record 616, TRB, National Research Council, Washington, D.C., 1976, pp. 71–73.

Ullidtz

Overlay and Stage by Stage Design. Proc., Fourth International Conference on the Structural Design of Asphalt Pavements, Ann Arbor, Mich., Vol. 1, 1977, pp. 722–735.

Irwin

, and Szebenyi

. User's Guide to MODCOMP3, Version 3.2, CLRP Report Number 91-4. Cornell University Local Roads Program, Ithaca, N.Y., 1991.

Witczak

M. W.

, and Uzan

. The Universal Airport Pavement Design System. Report I of IV: Granular Material Characterization. University of Maryland, Department of Civil Engineering, Sept. 1988.

Pellinen

K. T.

Investigation of the Use of Dynamic Modulus as an Indicator of Hot-Mix Asphalt Performance. Ph.D. thesis. Arizona State University, May 2001, p. 532.

10.

Uzan

Characterization of Asphalt Concrete Materials for Permanent Deformation. Internal Journal of Pavement Engineering, Vol. 4, No. 2, 2003, pp. 77–86.

Linear and Nonlinear Backcalculation for Site 1 in Hanover,New Hampshire

Abstract

Get full access to this article

References