Dynamic Interpretation of Falling Weight Deflectometer Test Results: Spectral Element Method

Abstract

The use of spectral analysis as a means of analyzing the dynamic impact of falling weight deflectometer (FWD) load pulses on pavements is covered. The spectral element technique is utilized. Only forward analyses of pavement dynamics are presented, with the emphasis on the suitability of the method for solving inverse problems. LAMDA (layered media dynamic analysis), a newly developed spectral element program, is utilized for the simulation of the interaction between the FWD load pulse and the pavement structure. In LAMDA, the formulation of the wave propagation, reflection, and refraction in a layer is done in a closed form. The assembling of the elements (in the multilayer system) is carried out in a manner similar to that in the finite element method. Consequently, the size of the mesh of a pavement structure is as large as the number of the layers involved. This reduces the computational requirements substantially and hence enables utilization of LAMDA in iterative algorithms for backcalculation purposes.

Get full access to this article

View all access options for this article.

References

van Gurp

Characterization of Seasonal Influences on Asphalt Pavements with the Use of Falling Weight Deflectometers. CIP, Delft, Netherlands, 1995.

Haskell

N. A.

The Dispersion of Surface Waves on Multilayered Media. Bulletin of the Seismological Society of America, Vol. 43, 1953. pp. 17–34.

Thomson

W. T.

Transmission of Elastic Waves Through a Stratified Solid Media. Journal of Applied Physics, Vol. 21, 1950. pp. 89–93.

Kausel

, and Roesset

J. M.

. Stiffness Matrices for Layered Soils. Bulletin of the Seismological Society of America, Vol. 71, 1981. pp. 1743–1761.

Lysmer

Lumped Mass Method for Rayleigh Waves. Bulletin of the Seismological Society of America, Vol. 60, 1970. pp. 89–104.

Tassoulas

J. L.

, and Kausel

. Elements for the Numerical Analysis of Wave Motion in Layered Strata. International Journal for Numerical Methods in Engineering, Vol. 19, 1983. pp. 1005–1032.

Doyle

J. F.

Wave Propagation in Structures: Spectral Analysis Using Fast Discrete Fourier Transforms. Springer-Verlag, Inc., New York, 1997.

Al-Khoury

, Scarpas

, Kasbergen

, and Blaauwendraad

. Spectral Element Technique for Efficient Parameter Identification of Layered Media, Part I: Forward Calculation. International Journal of Solids and Structures (recommended for publication).

Kreyszig

Advanced Engineering Mathematics. John Wiley and Sons, Inc., New York, 1993.

10.

Brigham

E. O.

The Fast Fourier Transform and Its Applications. Prentice-Hall, Inc., Englewood Cliffs, N.J., 1988.

11.

Scarpas

CAPA-3D Finite Elements System—User’s Manual, Parts I, II, and III. Department of Structural Mechanics, Faculty of Civil Engineering, Delft University of Technology, Netherlands, 1993.

12.

Foinquinos

, Roesset

J. M.

, and Stokoe

K. H.

II . Response of Pavement Systems to Dynamic Loads Imposed by Nondestructive Tests. In Transportation Research Record 1504, TRB, National Research Council, Washington, D.C., 1995. pp. 57–67.