CALCULATION OF BASIC FRICTION ANGLE IN ROCK JOINT USING TILT TEST

• Main Author: Nikher Kilikily, Rio
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/44056
• Institution: Institut Teknologi Bandung

One of the most influential rock mechanical properties in stability of slopes on stranded rock is rock shear strength. In previous studies related to the shear strength of stranded rocks with the Barton and Choubey criteria , one of the tests that need to be carried out to determine the shear strength characteristics of stranded rocks is a large-scale tilt test in a field which requires large amounts of cost and material. In fact, most practitioners today prefer to estimate the shear strength of stranded rock from the residual data of direct shear test for intact rock using the Mohr-Coulomb (MC) criteria; because this test is relatively easier and faster. However, there is a risk that the results obtained will be under-representation. According to Barton and Choubey (1977), the important parameters for estimating the rock shear strength in stranded rocks are Joint Roughness Coefficient (JRC), Joint Compressive Strength (JCS) and basic friction angle (?b) or residual friction angle (?r). The value of basic friction angle can be obtained from tilt testing on the laboratory scale. Some researchers had indicated that this can be done (Barton and Choubey 1977; J. Ruiz and C.Li. 2014; J. González.dkk 2014; Hyun-Sic Jang. Et al 2017; L.R Alejano et al. 2018). In this study, Three tilt testing methods suggested by the ISRM Suggested Method will be used in this study, namely the saw-cut method, the two-core method and the three-core method. The research object used in the tilt test consisted of concrete-made material with 3 different compositions of cement : sand which are (i.e. 1:1, 1:2, and 1:3). After the tilt testing on laboratory scale to determine the value of basic friction angle (?b), we would get a comparison of basic friction angle (?b) starting from the smallest to the largest (?b saw-cut < ?b two-core < ?b three-core).