**Author details**

**ML Sigma 1 Sigma 2 Sigma 3**

ML - 184

ML - 124

orientation

**Magnitude Dip Direction Magnitude Dip Direction Magnitude Dip Direction**

21.15 7.32 272.59 10.9 30 178 6.99 58.25 14.59

23.33 2.32 92.52 11.48 10.29 182.94 6.36 79.43 349.94

**Numerical modelling**

0.0069 Z + 20.924 R² = 0.5943

0.0055 Z + 10.158 R² = 0.9188

ML- 64 24.66 6.3 90.43 13.07 12.28 181.81 10.47 76.14 333.81

The modeling studies reveal that the measured value of the stresses agree reasonably with the

**(184 mL to 0 mL)**

R² = 0.7627

R² = 0.9862

The availability of stress results during pre - mining stage and subsequent measurement of stresses at the post mining stage has refined our understanding of the in-situ stress vis a vis mining. The change in the orientation of the major compression from a favourable N10-20 0 (Strike of ore body N 300 and crown pillar oriented parallel to ore body) during pre- mining stage to unfavourable N85-90 0 at the post mining stage has prompted to redesign the stopes

We are thankful to the Director National Institute of Rock Mechanics, India for the permission to publish the work. The authorities and staffs of Hindustan Copper limited are also thankfully

N 850 to N 900 N 900 to N 920

**Table 4.** Stress magnitude and orientation as revealed by numerical model

computation values which is compared in Table 5

**Stresses Post Mining Stage**

Stress gradient (σH) 0.0048 Z + 21.379

Stress gradient (σh) 0.01437 Z + 8.412

**Table 5.** Stress magnitude and orientation as revealed by numerical model

Maximum Horizontal principal Stress (σH)

924 Effective and Sustainable Hydraulic Fracturing

**8. Discussion and conclusion**

**Acknowledgements**

acknowledged.

and support systems below the mined out area.

Smarajit Sengupta, Dhubburi S. Subrahmanyam, Rabindra Kumar Sinha and Govinda Shyam

National Institute of Rock Mechanics, Bengaluru, India
