The effect of water saturation in sandstone and limestone samples on disc cutting performance

A study was undertaken to quantify the changes in disc cutter performance between dry and saturated rock. The tests were conducted using samples of limestone and sandstone to determine whether changes in performance are consistent across rock types. A linear rock cutting machine was used to conduct the tests with a rolling disc cutter. The tests were performed at varying depths with fixed disc spacing. Cutting forces were measured in the different rocks and cutting depths with rock yield determined and specific energy calculated. Comparing the results between cutting in dry and saturated rock showed reductions in cutting forces of 52% and 7% respectively for sandstone and limestone. That is the magnitude of the reduction in forces when cutting saturated rock was not consistent with a significant difference between the two rock types. The changes in specific energy were similar with a 43% and 9% reduction in sandstone and limestone. This difference in behaviour between the two rocks was also reflected in rock strength. A comparison of the strength between dry and saturated rock found the change was non-uniform with a 64% and 17% reduction in uniaxial compressive strength in the saturated sandstone and limestone samples respectively. When using a rolling disc cutter, rock cutting performance and rock strength were found to alter between dry and saturated conditions. In the case of a sandstone sample there were significant reductions in cutting forces, specific energy and strength whereas in limestone there were only marginal reductions in these parameters