Volume 33, Issue 6 (November 2010)

    Laboratory Performance Comparison of Stabilized Undercut Subgrade Under Cyclic Loading

    (Received 22 December 2009; accepted 29 July 2010)

    Published Online: 2010

    CODEN: GTJOAD

      Format Pages Price  
    PDF Version 10 $25   ADD TO CART


    Abstract

    This study evaluated the performance of undercut subgrade stabilization measures during construction traffic loading prior to final paving. Twenty-two simulated undercut sections with different stabilization configurations over a typically undercut Coastal Plain clay subgrade were built in a large-scale test pit. The subgrade was placed at a California Bearing Ratio of ∼2–3 % and stabilized with granular layers, granular layers reinforced with geosynthetics, and lime. Granular layers consisted of either aggregate base course (ABC), sandy select fill, or a multi-layer system with both soil types. The four geosynthetics tested were a woven reinforcement geotextile, a woven separation geotextile, and two biaxial polypropylene geogrids. The soft nature of the subgrade and its consequences on the ability to compact the ABC layer show the importance of carefully analyzing the results when viewed on a comparative basis. Cyclic plate loading simulating construction traffic showed that thicker granular layers produced less surface displacement, barring subgrade strength differences from remolding effects. Tests with lime stabilized subgrade showed the least magnitude of deformation over initial and post-rut repair cycles. ABC tests with geotextile showed improvement over unreinforced sections but only when placed at depths approximately equal to the loading plate diameter and after initial displacements mobilized the geosynthetic strength.


    Author Information:

    Cote, Benjamin
    E.I., GEI Consultants, Inc., Glastonbury, CT

    Robinson, Brent
    P.E., Dept. of Civil, Construction and Environmental Engineering, North Carolina State Univ., Raleigh, NC

    Pyo, Sangchul
    Dept. of Civil, Construction and Environmental Engineering, North Carolina State Univ., Raleigh, NC

    Park, Young Jin
    Dept. of Civil, Construction and Environmental Engineering, North Carolina State Univ., Raleigh, NC

    Gabr, Mohammed
    P.E., Dept. of Civil, Construction and Environmental Engineering, North Carolina State Univ., Raleigh, NC

    Borden, Roy
    P.E., Dept. of Civil, Construction and Environmental Engineering, North Carolina State Univ., Raleigh, NC


    Stock #: GTJ102935

    ISSN: 0149-6115

    DOI: 10.1520/GTJ102935

    ASTM International is a member of CrossRef.

    Author
    Title Laboratory Performance Comparison of Stabilized Undercut Subgrade Under Cyclic Loading
    Symposium , 0000-00-00
    Committee D18