ABSTRACT
The magnitude and direction of in-situ stresses are very important input parameters for any numerical modeling of underground structures. The Central Soil and Materials Research Station (CSMRS) conducted hydro-fracturing tests using Minifrac System in the drift located on the crown of proposed underground De-silting Chamber. The rock mass at the location of the drift is quartz biotite gneiss. In the present investigation, 28 hydro-fracturing tests were conducted inside three drill holes. Based on these tests results, the magnitude and direction of principal stresses have been determined. The vertical stress based on overburden is less than the vertical stress determined from hydro fracturing test. In general, the orientation of maximum horizontal stress is approximately in Easterly direction.
