LAUSR

The basic friction angle is a basic parameter for estimating the shear strength of rock discontinuities. The value of the basic friction angle can be determined using the tilt test. There are still no standard methods for such a test. Thus, the values from different researchers usually differ significantly for the same rock type. In this work, a number of tilt tests were conducted on core-based samples under different conditions. In this study, 33 different rock types and 53 groups of samples were collected, and more than 6,600 valid tilt tests were conducted. Based on the test results, some issues that may affect the value of the basic friction angle are discussed. This work may contribute to the present studies on the basic friction angle by tilt test.