Validation and Practical Application of a Data Reduction Software for the Analysis of Data from Stress Relief Tests

In his work "Rock Anisotropy and the Theory of Stress Measurements", Amadei (1983) highlights the importance of the correct geological-technical characterisation of the rocks involved in open pit or underground excavation works. At the laboratory of Geomechanics and Geotechnology (IGG-CNR, Polytechnic of Turin), a data reduction software has been developed which, based on the theory developed by Amadei, allows the estimation of the main stresses acting in selected volumes of rock, on the basis of strains resulting from over-coring, possibly taking into account the transverse isotropy of the material. This paper, after listing the most popular techniques for assessing the state of stress in on-site rocks, focuses on the stress relief method. In particular, the validation tests of the software, called BM2000, are presented, comparing the calculated results with those published by Amadei and with those provided by two software packages from the literature (Smith82, STRESsOUT). After having outlined the input data and the necessary adjustments for their application in the aforementioned software, the results obtained showed excellent correspondence, for the cases of both isotropic and transversely isotropic rock.