00627244

Component

http://onlinepubs.trb.org...trr/1992/1377/1377-013.pdf

https://scholar.google.co...EIDA&publication_year=1992

The development of improved procedures for the computation of effective stiffnesses of pavement layers from deflection bowls measured using the falling weight deflectometer (FWD) with particular emphasis give to the behavior of granular materials and subgrades is described. So far, the interpretation of FWD data at the University of Nottingham has been carried out using the computer program PADAL. In this program the pavement is represented by a series of linear elastic layers. The nonlinear properties of the subgrade are incorporated by dividing the subgrade into a series of sublayers, each having a different stiffness based on a stress-dependent elastic model derived from the results of laboratory repeated load triaxial tests. PADAL 2, an updated version of PADAL in which the nonlinearity of the subgrade is approximately modeled in the horizontal direction, has been developed. This modification allows for a more realistic description of the variability of elastic stiffnesses throughout the pavement. A comparison is made between two models incorporated in the back-analysis program to simulate the resilient behavior of fine-grained soils. FENLAP, a new finite element code for the structural analysis of pavements has been developed. The program includes a number of different nonlinear constitutive relationships. The finite element analysis may serve for calibrating the simpler layered elastic analysis approach. A pavement section is analyzed using the two computer programs, PADAL 2 and FENLAP.

This paper appears in Transportation Research Record No. 1377, Nondestructive Deflection Testing and Backcalculation for Pavements, Proceedings of a Symposium, August 19-21, 1991, Nashville, Tennessee. 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

01404955

English

p. 99-106

1992

Transportation Research Record

0309054206

Figures (3) ; References (8) ; Tables (2)

Accelerated tests; Backcalculation; Computer programs; Deflection; Elastic analysis; Falling weight deflectometers; Fine grained soils; Finite element method; Granular materials; Laboratory tests; Nonlinear systems; Pavement layers; Pavements; Repeated loads; Resilience (Materials); Stiffness; Structural analysis; Subgrade (Pavements); Triaxial shear tests

Layered elastic analysis; Nonlinearity; Triaxial tests

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

TRIS, TRB, ATRI

Apr 5 1993 12:00AM

• ASPHALT THICKNESS VARIATION ON TEXAS STRATEGIC HIGHWAY RESEARCH PROGRAM SECTIONS AND EFFECT ON BACKCALCULATED MODULI
• BACKCALCULATION OF DESIGN PARAMETERS FOR RIGID PAVEMENTS
• COMPARISON OF BACKCALCULATED MODULI FROM FALLING WEIGHT DEFLECTOMETER AND TRUCK LOADING
• COMPARISON OF PAVEMENT DEFLECTION ANALYSIS METHODS USING OVERLAY DESIGN
• COMPARISON OF THEORETICAL AND IN SITU BEHAVIORS OF A FLEXIBLE PAVEMENT SECTION
• CONCRETE PAVEMENT BACKCALCULATION RESULTS FROM FIELD STUDIES
• CORRELATION BETWEEN BACKCALCULATED AND LABORATORY-DETERMINED ASPHALT CONCRETE MODULI
• EFFECT OF THICKNESS AND TEMPERATURE CORRECTIONS ON PREDICTION OF PAVEMENT STRUCTURAL CAPACITY USING FALLING WEIGHT DEFLECTOMETER DATA
• IMPLEMENTATION OF BACKCALCULATION IN PAVEMENT EVALUATION AND OVERLAY DESIGN IN OREGON
• IMPLEMENTATION OF FALLING WEIGHT DEFLECTOMETER LOAD-ZONING PROCEDURE IN TEXAS
• INFLUENCE OF STATISTICAL VARIATION IN FALLING WEIGHT DEFLECTOMETERS ON PAVEMENT ANALYSIS
• INTERPRETATION OF BACKCALCULATED LAYER MODULI OF CRACK-AND-SEAT PAVEMENT FROM FALLING WEIGHT DEFLECTOMETER DATA
• LAYER MODULI DETERMINATION DURING FREEZE-THAW PERIODS
• LAYER MODULI FROM DEFLECTION MEASUREMENTS: SOFTWARE SELECTION AND DEVELOPMENT OF STRATEGIC HIGHWAY RESEARCH PROGRAM'S PROCEDURE FOR FLEXIBLE PAVEMENTS
• NONDESTRUCTIVE TESTING WITH FALLING WEIGHT DEFLECTOMETER ON WHOLE AND BROKEN ASPHALT CONCRETE PAVEMENTS
• RAPID DETERMINATION OF LAYER PROPERTIES OF PAVEMENTS FROM SURFACE WAVE METHOD
• REPORT OF THE DISCUSSION GROUP ON BACKCALCULATION LIMITATIONS AND FUTURE IMPROVEMENTS
• REPORT OF THE DISCUSSION GROUP ON CURRENT AND FUTURE APPLICATIONS OF NONDESTRUCTIVE DEFLECTION MEASUREMENTS
• REPORT OF THE DISCUSSION GROUP ON PRACTICAL LIMITATIONS AND WHAT CAN BE DONE TO OVERCOME THEM
• STRATEGIC HIGHWAY RESEARCH PROGRAM FALLING WEIGHT DEFLECTOMETER QUALITY ASSURANCE SOFTWARE
• VALIDATION OF MODULI BACKCALCULATION PROCEDURE USING MULTIDEPTH DEFLECTOMETERS INSTALLED IN VARIOUS FLEXIBLE PAVEMENT STRUCTURES
• VARIABILITY IN MEASURED DEFLECTIONS AND BACKCALCULATED MODULI FOR THE STRATEGIC HIGHWAY RESEARCH PROGRAM SOUTHERN REGION