00615730

Component

http://onlinepubs.trb.org...trr/1991/1293/1293-007.pdf

https://scholar.google.co...iggs&publication_year=1991

The extraction of engineering properties of pavement layers by dynamic analysis of falling weight deflectometer (FWD) data is demonstrated. FWD data from two in-service highway sections were analyzed. The FWD data consist of time records of surface loading and surface deflections at a range of distances. A Texas Transportation Institute pavement dynamics computer program, SCALPOT, was used to generate predicted responses. Physical properties of the pavement were generated by a trial-and-error backcalculation and a Systems Identification computer program. The pavement surface vertical deflections were characterized by using frequency response functions in the form of magnitude and phase angle plots as a function of frequency. The magnitude plots represent vertical pavement surface deformations resulting from a steady-state sinusoidal surface loading. The phase angle data represent the lag angle between the loading and the surface deflections. The asphaltic concrete surface layer was represented as a three-parameter viscoelastic medium. The base course, subgrade layers, and bedrock layers, if any, were treated as damped elastic solids. These physical properties were backcalculated by matching approximately the frequency-analyzed field data with computed values by varying the SCALPOT input data set. Good agreement between experimental and computer-predicted responses was obtained using the backcalculated pavement layer properties. One site with near-surface bedrock was analyzed and good agreement was obtained.

This paper appears in Transportation Research Record No. 1293, Backcalculation of Pavement Moduli 1991. 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

01411133

p. 61-71

1991

Transportation Research Record

0309051010

Figures (9) ; References (17) ; Tables (4)

Alternatives analysis; Asphalt concrete; Backcalculation; Computer programs; Deflection; Dynamic tests; Falling weight deflectometers; Field studies; Forecasting; Frequency response; Functions (Mathematics); Measurement; Pavements

Dynamic analysis; Field data

Data and Information Technology; Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces

TRIS, TRB, ATRI

Sep 30 1991 12:00AM

• ACCURACY AND CONSISTENCY OF BACKCALCULATED PAVEMENT LAYER MODULI
• ADVANCED BACKCALCULATION USING A NONLINEAR LEAST SQUARES OPTIMIZATION TECHNIQUE
• BACKCALCULATION OF ASPHALT CONCRETE-OVERLAID PORTLAND CEMENT CONCRETE PAVEMENT LAYER MODULI
• CALCULATING PAVEMENT DEFLECTIONS WITH VELOCITY TRANSDUCERS
• CHARACTERIZATION OF FALLING WEIGHT DEFLECTOMETER DEFLECTION BASIN
• COMPARISON OF DYNAMIC AND STATIC BACKCALCULATION MODULI FOR THREE-LAYER PAVEMENTS
• DETECTION AND DETERMINATION OF DEPTH OF RIGID BOTTOM IN BACKCALCULATION OF LAYER MODULI FROM FALLING WEIGHT DEFLECTOMETER DATA
• DEVELOPMENT OF AN ABSOLUTE CALIBRATION SYSTEM FOR NONDESTRUCTIVE TESTING DEVICES
• EFFECT OF VARIOUS LOAD DISTRIBUTIONS ON BACKCALCULATED MODULI VALUES IN FLEXIBLE PAVEMENTS
• ESTIMATION OF PAVING MATERIALS DESIGN MODULI FROM FALLING WEIGHT DEFLECTOMETER MEASUREMENTS
• FULL-SCALE ACCELERATED PAVEMENT TESTING FOR THE TEXAS STATE DEPARTMENT OF HIGHWAYS AND PUBLIC TRANSPORTATION
• RELATING DEFLECTION DATA TO PAVEMENT STRAIN