00625539

Component

http://onlinepubs.trb.org...trr/1992/1355/1355-001.pdf

https://scholar.google.co...e+II&publication_year=1992

The falling weight deflectometer (FWD) has been used in the evaluation of material properties of pavement systems for many years. The load amplitude and frequency content are intended to provide deformation levels similar to those induced by truck wheel loads. Interpretation of the in situ measured data is normally based on an elastic solution and therefore does not take into account the possible existence of localized nonlinearities. The objective of this work was to develop some understanding of the potential for nonlinear behavior in the FWD test. Analytical studies were conducted using both a linear iterative solution and a nonlinear solution with the generalized cap model to reproduce the nonlinear soil behavior. Three pavement sections in Texas were considered using the finite discrete model. By varying the level of loads FWD deflection basins, induced strains, and inelastic material properties were obtained. The results of this study indicate that material nonlinearities are localized and are important for FWD tests on flexible pavements where the subgrade is relatively soft or the pavement is thin. In these cases, nonlinear effects increase peak displacements by at least 50% under a 20,000-lb load but are negligible for receivers at 3 ft or more from the source. In general, a FWD test with a load of 2,000 lb or less would not result in any apparent nonlinear effects at any pavement site. For FWD tests on rigid pavements or flexible pavements with a relatively stiff subgrade, nonlinearities are also less pronounced.

This paper appears in Transportation Research Record No. 1355, Nondestructive Structural Evaluation of Pavements. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved

01405034

English

p. 1-7

1992

Transportation Research Record

030905219X

Figures (12) ; References (13) ; Tables (3)

Falling weight deflectometers; Flexible pavements; Nonlinear systems; Pavements; Properties of materials; Rigid pavements; Stiffness; Structural tests; Subgrade (Pavements)

Nonlinearity

Bridges and other structures; Design; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces

TRIS, TRB, ATRI

Dec 16 1993 12:00AM

• ALTERNATIVE METHOD FOR TEMPERATURE CORRECTION OF BACKCALCULATED EQUIVALENT PAVEMENT MODULI
• COMPREHENSIVE EVALUATION OF FIVE SENSORS USED TO MEASURE PAVEMENT DEFLECTION
• EFFECT OF DEPTH TO BEDROCK ON DEFLECTION BASINS OBTAINED WITH DYNAFLECT AND FALLING WEIGHT DEFLECTOMETER TESTS
• EFFECTS OF BUFFERS ON FALLING WEIGHT DEFLECTOMETER LOADINGS AND DEFLECTIONS (WITH DISCUSSION)
• ESTIMATING DAMAGE EFFECTS OF DUAL VERSUS WIDE BASE TIRES WITH MULTIDEPTH DEFLECTOMETERS
• EVALUATION OF A DUAL-LOAD NONDESTRUCTIVE TESTING SYSTEM TO BETTER DISCRIMINATE NEAR-SURFACE LAYER MODULI
• FIELD AND LABORATORY DETERMINATION OF ELASTIC PROPERTIES OF PORTLAND CEMENT CONCRETE USING SEISMIC TECHNIQUES
• MODELING OF GROUND-PENETRATING RADAR WAVE PROPAGATION IN PAVEMENT SYSTEMS
• RADAR PAVEMENT THICKNESS EVALUATIONS FOR VARYING BASE CONDITIONS
• SIMPLIFIED, RATIONAL APPROACH TO FALLING WEIGHT DEFLECTOMETER DATA INTERPRETATION
• VARIABILITY IN ESTIMATION OF STRUCTURAL CAPACITY OF EXISTING PAVEMENTS FROM FALLING WEIGHT DEFLECTOMETER DATA