Effects of Water Saturation on the Dynamic Compression and Fragmentation Response of Gabbroic Rock

This study investigates the water saturation effects on the dynamic compressive strength and fragmentation behavior of Indian gabbronorite. A selection of gabbronorite was divided into specimens that were either saturated in distilled water for 120 days or dried in a vacuum oven at 105 ^∘ C. The specimens were then compressed to failure at a strain rate on the order of 10^2 s^-1 using a Kolsky (split-Hopkinson) bar and compared with quasi-static results. The dynamically compressed oven-dried gabbronorite exhibited a 64% increase in ultimate compressive strength compared to identical specimens compressed quasi-statically, while dynamically loaded saturated specimens exhibited a 77% increase compared with those tested quasi-statically. Under dynamic conditions, saturated specimens exhibited a 27% reduction in ultimate compressive strength compared to dried gabbronorite under the same loading conditions. Under quasi-static conditions, saturated gabbronorite exhibited 32% lower compressive strength than equivalently loaded dry specimens. After compression, the resulting fragments were collected and measured for their characteristic length and size distributions. Saturated gabbronorite produced fewer fragments smaller than 200 m when compared to dry specimens under equivalent dynamic loading conditions. Finally, fragments of both saturated and dried specimens were found to follow log-normal size distributions.