Volume 37, Issue 4 (July 2014)

    Experimental Group Behavior of Grouted Deep Foundations

    (Received 25 August 2013; accepted 18 March 2014)

    Published Online: 2014

    CODEN: GTJOAD

      Format Pages Price  
    PDF 19 $25   ADD TO CART


    Abstract

    Post-grouting of deep foundations following installation is a proven technique for enhancing axial resistance. The grouting is performed either below the tip of the foundation only (e.g., post-tip-grouted drilled shafts) or at both the side and the tip (e.g., jetted, side, and tip-grouted precast piles). The interaction of such foundations in group placement is currently unknown. This research focused on the group behavior of post-tip-grouted drilled shafts and jetted, side, and tip-grouted piles at a center-to-center spacing of three times the pile/shaft diameter. The study revealed that the post-tip-grouted drilled shafts acted independently within the group (i.e., negligible group interaction), whereas jetted, side, and tip-grouted piles behaved as a block under axial loading. It was determined that side grouting of a foundation prior to tip grouting significantly increases the grout pressure developed during tip grouting and helps in the formation of a tip grout bulb via a spherical cavity expansion process. Thus, the side and tip grouting of adjacent foundations within a group increases the confining stress and relative density of the soil mass within the group, resulting in block behavior under top-down loading. In contrast, tip-only grouted foundations showed little if any increase in radial stress and radial soil displacement, resulting in minimal improvement of the soil stiffness between shafts; as a result there was no block behavior and a negligible group effect at the tip.


    Author Information:

    Thiyyakkandi, Sudheesh
    Post-doctoral Associate, Engineering School of Sustainable Infrastructure and Environment, Univ. of Florida, Gainesville, FL

    McVay, Michael
    Professor, Engineering School of Sustainable Infrastructure and Environment, Univ. of Florida, Gainesville, FL

    Lai, Peter
    Retired Assistant State Geotechnical Engineer, Florida Dept. of Transportation, Tallahassee, FL


    Stock #: GTJ20130144

    ISSN: 0149-6115

    DOI: 10.1520/GTJ20130144

    ASTM International is a member of CrossRef.

    Author
    Title Experimental Group Behavior of Grouted Deep Foundations
    Symposium , 0000-00-00
    Committee D18