|
|
|
Title: ANALYSIS OF PROCEDURES FOR ESTABLISHING IN SITU SUBGRADE MODULI
Accession Number: 00677584
Record Type: Component
Availability: Find a library where document is available Abstract: Through the efforts of the Strategic Highway Research Program Long-Term Pavement Performance study, a vast amount of data has been collected on hundreds of pavement test sections across North America. As part of this effort, extensive subgrade data have been collected, including Atterberg limits, gradations, moisture contents, deflection data, laboratory resilient moduli, and subgrade profiles. With this wealth of information on the subgrade and its associated properties, it becomes possible to evaluate previously proposed methods for determining the subgrade resilient moduli and possibly to develop new models to improve the ability to estimate soil support conditions for pavement design purposes. Three methods for determining the subgrade resilient moduli are considered: laboratory testing, backcalculation using deflections measured from nondestructive testing (NDT), and an estimation equation contained in the 1986 AASHTO Guide. There is currently no consensus as to which moduli value should be used for pavement design. An attempt is made to develop relationships between the various sources for moduli prediction. Based on the data currently available, there appears to be little if any relationship between these various methods for determining the resilient modulus of a subgrade. Efforts were made to develop moduli prediction equations based on various subgrade properties and NDT. The subgrades were separated into basic soil classifications (clay, sand, and silt) and models were developed for each subgrade type. Each model contains the load and sensor 7 reading from falling weight deflectometer test results. Other properties that proved to be significant were the thicknesses of the pavement layers, percent saturation of the subgrade, dry densities, and specific gravities.
Supplemental Notes: This paper appears in Transportation Research Record No. 1462, Compaction of Difficult Soils and Resilient Modulus Testing. 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
Monograph Title: Monograph Accession #: 01495760
Language: English
Authors: Daleiden, Jerome FKillingsworth, Brian MSimpson, Amy LZamora, Richard APagination: p. 102-107
Publication Date: 1994
Serial: ISBN: 0309060680
Features: Figures
(2)
; References
(4)
; Tables
(5)
TRT Terms:
Backcalculation; Databases; Deflection tests; Dry density; Equations; Falling weight deflectometers; Forecasting; Laboratory tests; Mathematical models; Modulus of resilience; Nondestructive tests; Pavement layers; Pavement performance; Percent saturation; Soil types; Specific gravity; Subgrade (Pavements); Thickness
Identifier Terms: Old TRIS Terms: Subject Areas: Data and Information Technology; Geotechnology; Highways; I42: Soil Mechanics
Files: TRIS, TRB
Created Date: May 3 1995 12:00AM
More Articles from this Serial Issue:
|
