A state-of-the-art anisotropic rock deformation model incorporating the development of mobilised shear strength

• Main Authors: Jobli, A.F (Author), Md Noor, M.J (Author)
• Format: Article
• Language: English
• Published: Institute of Physics Publishing 2018
• Subjects: Anisotropic stress; Anisotropic stress conditions; Anisotropy; Compression testing; Confining pressures; Deformation; Deformation modulus; Forecasting; Intrinsic property; Rock pressure; Rocks; Strain; Stress-strain curves; Stress-strain relationships; Sustainable development; Unconfined compression tests; Weathered granites
• Online Access: View Fulltext in Publisher; View in Scopus

 Currently rock deformation is estimated using the relationship between the deformation modulus Em and the stress-strain curve. There have been many studies conducted to estimate the value of Em. This Em is basically derived from conducting unconfined compression test, UCS. However, the actual stress condition of the rock in the ground is anisotropic stress condition where the rock mass is subjected to different confining and vertical pressures. In addition, there is still no empirical or semi-empirical framework that has been developed for the prediction of rock stress-strain response under anisotropic stress condition. Arock triaxial machine GCTS Triaxial RTX-3000 has been deployed to obtain the anisotropic stress-strain relationship for weathered granite grade II from Rawang, Selangor sampled at depth of 20 m and subjected to confining pressure of 2 MPa, 7.5 MPa and 14 MPa. The developed mobilised shear strength envelope within the specimen of 50 mm diameter and 100 mm height during the application of the deviator stress is interpreted from the stress-strain curves. These mobilised shear strength envelopes at various axial strains are the intrinsic property and unique for the rock. Once this property has been established then it is being used to predict the stress-strain relationship at any confining pressure. The predicted stress-strain curves are compared against the curves obtained from the tests. A very close prediction is achieved to substantiate the applicability of this rock deformation model. This is a state-of-the art rock deformation theory which characterise the deformation base on the applied load and the developed mobilised shear strength within the rock body. © 2018 Published under licence by IOP Publishing Ltd.