Investigation on the unconfined compression strength of rocks by experimental tests and advanced numerical modelling technique

The mechanical response of a middle strength rock, namely Pietra sandstone, is assessed both numerically and experimentally under unconfined compressive loading condition. Two experimental approaches, based on different specimens' arrangements, have been conducted on Pietra Serena sandstone to determine its unconfined compressive strength (UCS). This parameter greatly influences the boreability of rocks and a precise method for obtaining this parameter is thus always required. The experimental tests have been replicated in LS-DYNA in conjunction with an advanced material model, called the Karagozian and Case Concrete (KCC) model, to benchmark the results and, therefore, to conclude which experimental approaches yield the most reliable results.