United States Department of Transportation
i
Development of Testing Protocol and Correlations for Resilient Modulus of Subgrade Soils
-
2005-01-01
[PDF-2.93 MB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Resource Type:
-
Geographical Coverage:
-
TRIS Online Accession Number:01030728
-
Edition:Final Report July 1, 2002 - June 30, 2005
-
Corporate Publisher:
-
Abstract:This study provides a description of the theoretical aspects of Spectral Analysis of Surface Waves (SASW) method for determining the thickness and resilient moduli of pavement systems, and presents the results of testing performed using an SASW system assembled as part of this research. The SASW method is based on the dispersive behavior of surface waves in a layered medium. Dispersion is the term used to describe the fact that the rate at which seismic surface waves (Rayleigh waves) travel through a medium depends upon the frequency of the waves, and this dependency can be used to determine mechanical properties of the medium through which the waves travel. Plotting Rayleigh wave velocity versus frequency (or wavelength) produces a graph called a dispersion curve. This dispersion curve can be used to develop a modulus versus depth profile through the use of a backcalculation procedure. Once the modulus versus depth profile is known, the resilient modulus and thickness of individual layers can be directly obtained. The results obtained from SASW testing at ten flexible pavement sites throughout the state of Arkansas are presented as part of this report. The thickness and resilient modulus of each layer of each pavement section are estimated from the SASW data using two methods of analysis; simple inversion, and software provided by the University of Texas at El Paso. The thickness results obtained from SASW analyses are compared to known thicknesses measured from cores taken at each of the test sites. The resilient moduli predicted by SASW analysis are compared to the resilient moduli predicted by laboratory resilient modulus testing, to the resilient moduli predicted by Falling Weight Deflectometer (FWD) analysis, and to Standard Penetration test N-values. The simple inversion procedure provided the most consistent results for SASW testing. SASW methods proved to be very accurate in predicting the thickness of various layers in a pavement system and correlated well with the results from laboratory resilient modulus testing.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
