165137 20251212165958.0 doi 10.1016/j.jrmge.2024.11.024 sideral 146579 ART-2025-146579 eng Úcar, Roberto Estimating rock strength parameters across varied failure criteria: Application of spreadsheet and R-based orthogonal regression to triaxial test data 2025 Triaxial tests, a staple in rock engineering, are labor-intensive, sample-demanding, and costly, making their optimization highly advantageous. These tests are essential for characterizing rock strength, and by adopting a failure criterion, they allow for the derivation of criterion parameters through regression, facilitating their integration into modeling programs. In this study, we introduce the application of an underutilized statistical techniquedorthogonal regressiond well-suited for analyzing triaxial test data. Additionally, we present an innovation in this technique by minimizing the Euclidean distance while incorporating orthogonality between vectors as a constraint, for the case of orthogonal linear regression. Also, we consider the Modified Least Squares method. We exemplify this approach by developing the necessary equations to apply the Mohr-Coulomb, Murrell, Hoek-Brown, and Úcar criteria, and implement these equations in both spreadsheet calculations and R scripts. Finally, we demonstrate the technique's application using five datasets of varied lithologies from specialized literature, showcasing its versatility and effectiveness. Access copy available to the general public Unrestricted info:eu-repo/grantAgreement/ES/DGA/E32-23R info:eu-repo/semantics/openAccess by-nc-nd https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Arlegui, Luis Universidad de Zaragoza (orcid)0000-0001-5091-9398 Belandria, Norly Torrijo, Francisco 2000 428 Universidad de Zaragoza Dpto. Ciencias de la Tierra Área Geodinámica Interna 17, 8 (2025), 4685-4699 Journal of Rock Mechanics and Geotechnical Engineering 1674-7755 1770128 http://zaguan.unizar.es/record/165137/files/texto_completo.pdf Versión publicada 2634799 http://zaguan.unizar.es/record/165137/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:165137 articulos driver 2025-12-12-14:43:30 ARTICLE