https://mega.nz/file/1nFEnDRK#rVAoXLSQ7lFK7ydwrwM9TuleC_2JQmDZeTsW1nKKJYc
Rock cores drilled under high in situ stress environments are inevitably permanently damaged due to the stress relief, which significantly affects the evaluation of the physical and mechanical properties of deep rocks. Quantitatively correlating this sampling damage with in situ stress
distribution is challenging because of the complexity of the geological environment and the diversity of rock materials. To address this challenge, a laboratory test apparatus has been developed that can apply specific pressure to shallow rock materials to simulate high in situ
stress environments and drilling–coring to simulate the sampling process of deep rock masses. The results of verification tests demonstrate that the integrity of cores gradually deteriorated
as the sampling confining pressure increased. Moreover, simultaneous increases in the density and size of microcracks were observed within the cores, where these microcracks propagate through grain boundaries, generate intragrain and transgranular microcracks, extend outwardly
to form macroscopic cracks, and enhance porosity.