Triaxial Compression Test Characteristics of Limestone from Gunung Lang, Malaysia

Abstract

The shear characteristics of rock materials are input parameters for reservoir geomechanics, wellbore stability, subsidence prediction, and underground structure numerical modeling. One of the most important shear characteristics of rock material is the significant increase in rock material strength with increasing confining pressure. This can be described from the triaxial compression test where rock material samples were subjected to increasing confining pressure in order to investigate the stress–strain relationship that the rock experienced and thus the failure strength envelope. For many years, multistage triaxial compressive strength has been increasingly used by rock mechanics engineers to determine the Mohr–Coulomb failure envelope of rock material. The literature study revealed that there was less publication emphasizing on shear strength of Malaysian limestone using triaxial compression test. With that, this paper presents the result of four sets of multistage triaxial testing with confining pressures ranging from 1 to 15 MPa, conducted on limestone sample from Gunung Lang, Malaysia. From the Mohr–Coulomb failure envelope, the range and mean of friction angle, ϕ, and cohesion, C, range from 46° to 54.2° with mean of 49.6° and 12–28 MPa and with mean of 14.5 MPa, respectively. With regard to the information presented in this paper, it was anticipated that the presented result will provide important rock strength characteristics for subsequent use in rock strength analysis in Malaysia.