Investigation of the True Triaxial Failure Mechanism for a Medium Strength Sandstone Report 3: Classic Triaxial testing result and model calibration

Abstract

This technical report was prepared following a request from SCT Operations Pty Ltd for a geomechanical study on a medium strength sandstone. This study investigated the behaviour of Hawkesbury sandstone under true triaxial stress conditions, including 15 tests on 50 mm cubic samples. Report 1&2 were already submitted and this report summarises the classic triaxial testing on 4 samples, two of which were cored in horizontal and the rest in vertical directions. Table one summarises testing conditions. Rock mechanical parameters were taken from Gu (2001, Page 81) and estimated ultimate strength was calculated based on Mohr-Coulomb failure criteria. Figure 1 shows the UCS test on the sample ID 18 with the strain gauges being attached to the sample. Also, the whole loading setup for a single stage confined test is shown in this figure.