An experimental determination of the true uniaxial stress-strain behavior of brittle rock.
Brady-BT; Duvall-WI; Horino-FG
Rock Mech Rock Eng 1973 Aug; 5(2):107-120
Results are presented of an experimental study of the behavior of six rock types deformed under uniaxial compression into their respective post-failure regions. Based on the observation that a rock sample in a post-failure state can be considered to be composed of broken and unbroken rock and assuming that the reduction in load-bearing capability of rock in the post-failure region is due to a reduction of the effective cross-sectional area of the specimen resulting from the growth of large cracks within the rock sample, the authors show that there is a maximum true stress that the unfractured solid rock can sustain without inelastic deformation. This stress is constant and is defined to be the true failure strength of the rock. The value of this stress is calculated by dividing the force on the rock sample at any point along the postfailure curve by the true load-bearing cross-sectional area of the rock sample at that point. Theoretical and experimental techniques are developed which allow an estimate of the true load- bearing area of the rock sample at any point along the postfailure curve of the sample. For the rock types used in the study, which were deformed to preselected positions along their respective post-failure curves and with the assumption that the fractured rock carried none of the applied load, the two techniques of measuring the effective load-bearing area give results which are equivalent.
Mining-industry; Underground-mining; Rock-mechanics; Geology
OP; Journal Article
Rock Mechanics and Rock Engineering