00641444

Component

http://onlinepubs.trb.org...trr/1993/1406/1406-015.pdf

https://scholar.google.co...ddin&publication_year=1993

The characterization of soils in terms of resilient behavior is gaining support because of its immediate application in the mechanistic analysis of pavements. This report investigates an alternative procedure of resilient testing using the U.S. Army Corps of Engineers gyratory testing machine (GTM). The development of the GTM test procedure, focusing on the simulating conditions of a moving load, is summarized. With consideration to specimen confinement in the mold, a revised equation for kneading resilient modulus (M sub rk) is presented. The primary objective is to validate the GTM test procedure. For that purpose, six subgrade soils and three subbase materials are investigated using the GTM and the repeated load triaxial test, AASHTO T274-82. For in situ determination of resilient modulus of some of those soils (five samples only), Dynaflect and falling weight deflectometer deflections are obtained on finished pavements as well. Two computer programs--MODULUS and FPEDD1--were used to backcalculate the moduli of all of the layers. The GTM moduli compare poorly with the triaxial moduli in this nine-soil comparative study, nor was there any correlation between M sub rk and the backcalculated moduli when the latter was not corrected for nonlinear effects. However, the in situ modulus values (only five sites tested) agree with the GTM moduli with appropriate nonlinear correction, as programmed in FPEDD1. On the basis of the successful comparison with the in situ backcalculated moduli, it is concluded that GTM has the potential for resilient modulus characterization of subgrade soils.

This paper appears in Transportation Research Record No. 1406, Construction Robotics and Automation, and Foundations Engineering. 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

01403255

English

p. 116-123

1993

Transportation Research Record

0309055539

Figures (5) ; References (14) ; Tables (4)

Accelerated tests; Alternatives analysis; Backcalculation; Computer programs; Deflection; Dynaflect; Falling weight deflectometers; Gyratory testing machines; Modulus of resilience; Repeated loads; Soils; Subbase materials; Subgrade (Pavements); Test procedures; Triaxial shear tests; Validation

Nonlinear effects; Triaxial tests

Data and Information Technology; Geotechnology; Highways; I42: Soil Mechanics

TRIS, TRB, ATRI

Jan 25 1994 12:00AM

• APPLICABILITY OF RESILIENT CONSTITUTIVE MODELS OF GRANULAR MATERIAL FOR UNBOUND BASE LAYERS
• COLORADO'S KNOWLEDGE SYSTEM FOR RETAINING WALL SELECTION
• COSTS AND BENEFITS OF AUTOMATED ROAD MAINTENANCE
• DEFORMATION CHARACTERISTICS OF SUBGRADE SOILS IN KUWAIT
• DISPERSIVE CLAY EMBANKMENT EROSION: A CASE HISTORY
• EFFECTS OF COMPACTOR FOOTPRINTS ON THE RESPONSE OF SUBGRADE SOIL
• EXPERT SYSTEM FOR DRILLED SHAFT CONSTRUCTION
• FIELD AND LABORATORY EVALUATION OF THE MECHANICAL BEHAVIOR OF UNBOUND GRANULAR MATERIALS IN PAVEMENTS
• GEOTECHNICAL CHARACTERISTICS OF SALT-BEARING SOILS IN KUWAIT
• INTERFERENCE EFFECTS BETWEEN TWO SURFACE FOOTINGS ON LAYERED SOIL
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• PREDICTED AND OBSERVED BEHAVIOR OF A DEEP-SOIL-MIXING BRACED WALL
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• TOWARD AN ADAPTIVE CONTROL MODEL FOR ROBOTIC BACKHOE EXCAVATION