Assessment of Effect of Anisotropy On Failure Mode and Shear Parameters of Chamoli Rock Using Triaxial System

The Chamoli district of Uttarakhand (India) due to its spiritual significance attracts more and more people every year which demands rapid development of infrastructure in terms of highways, railways, tunnels, hydropower, and tourism facilities. Chamoli region has been witnessing heavy landslides/rockslides for the last many years and the frequency of such disasters is rapidly increasing drawing major loss of human lives and the economy. The objective of this research paper is to examine the effect of natural foliation and the anisotropic behavior of metamorphic rock (Chamoli, Uttarakhand) on shear characteristics and failure patterns through different orientation angles of natural schistosity using an automated triaxial system. Further, the effect on dynamic properties of the natural foliation of rock using ultrasonic pules velocity test based on longitudinal and shear wave velocity is estimated using co-relations. A cylindrical specimen of diameter 50mm and length of 100mm is cored from collected chunk at different orientation angles of natural schistosity (0°, 15°, 30°, 45°, 60°, 75°and 90°). The strength of the different anisotropic rocks was estimated using the Mohr-Coulomb strength theory (1900) and modified Hoek- Brown strength theory (2016). Simulation of foliation at different degrees reveals how the failure planes propagate under natural formations and the effect of bonding under confining pressures.