Retrieving "Borehole Drilling" from the archives

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  1. Rock Mass

    Linked via "borehole"

    The five primary input parameters are:
    Strength of intact rock material ($R_1$): Rated from 1 (very low strength, e.g., soft shales [1]) to 15 (extremely high strength, e.g., quartzite).
    Rock Quality Designation (RQD) ($R_2$): A measure of the percentage of core running 10 cm or longer in a borehole. Low values indicate high fracture density.
    Spacing of discontinuities ($R_3$): B…