STP1198: A Comparison of Laboratory and Field Sdbgrade Moduli at the Minnesota Road Research Project

    Van Deusen, DA
    Research Fellow, University of Minnesota, Minneapolis, MN

    Lenngren, CA
    Post-Doctoral Research Associate, University of Minnesota, Minneapolis, MN

    Newcomb, DE
    Assistant Professor, University of Minnesota, Minneapolis, MN

    Pages: 19    Published: Jan 1994


    Abstract

    A soil sampling and testing program was conducted on the pavement embankment at the Minnesota Road Research Project. Both destructive and nondestructive approaches were taken. Nondestructive load tests were conducted both before and after base construction using a falling-weight deflectometer; both disturbed and undisturbed soil samples were retrieved. Falling-weight deflectometer tests were conducted at regular intervals along three different offsets directly on the soil embankment. A large diameter plate was used with modest load levels. Other data obtained during the testing program included jar, bag, and thin-wall soil samples, and dynamic cone penetrometer soundings. The falling-weight deflectometer load and deflection data were used to backcalculate the elastic moduli for a multi-layered system. Due to the variability in the surface conditions special backcalculation techniques had to be employed. The variability of the deflections and estimated moduli were addressed using both general statistics and geostatistical analyses. The backcalculated moduli for the near-surface layers were softer and more variable than the deeper layer. Laboratory resilient modulus tests conducted on the thin-wall samples yielded values that compared well with the backcalculated values from the deeper layer.

    Keywords:

    non-destructive testing, falling-weight deflectometer, moduli backcalculation, subgrade testing, subgrade variability


    Paper ID: STP18159S

    Committee/Subcommittee: D04.39

    DOI: 10.1520/STP18159S


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