Correlation of Deformation Modulus by PMT with RMR and Rock Mass Condition

摘要

In this paper, the applicability of available correlations that estimate the deformation modulus fromrnRock Mass Rating (RMR) and Pressuremeter Test (PMT) to the Korean rock mass is evaluated. Therncorrelations between deformation modulus and other rock properties were also analyzed. It appearsrnthat the existing correlations using RMR overestimate the deformation moduli and wide variation wasrnfound between predicted moduli and the measured values. Rock Quality Designation (RQD) andrnunconfined compressive strength (UCS) were found to correlate to deformation modulus reasonablyrnwell, but joint spacing and joint conditions appear to correlate poorly to RQD and UCS. Groundwaterrncould not be correlated to the modulus. The measurement depth was found to have very littlerncontribution to deformation modulus. However, it is estimated that poor correlation result from thernfact that measurement depth is coupled with not only with the deformation modulus, but with otherrnfactors including strength, joint condition, and degree of weathering. The inappropriateness of therncorrelations clearly demonstrate that more in depth analysis techniques such as multivariaterncorrelations is needed to better estimate deformation modulus of rock mass from available rockrnproperties.