In Rajpura Dariba mine, the presence of ancient workings posed problems for mining the orebody at shallow depth. Under this condition, it was not possible to continue with the existing cut and fill method. In view of these, sub-level caving method was proposed for mining the orebody. The mining would be done above the existing cut and fill stopes, without leaving any crown pillar. As the extractable height of the orebody was 40 m, it was proposed to devide the orebody in four blocks, each 10 m in height.
The numerical model analysis has revealed that the stoping can be done safely, if the lag between each block is kept 4 m and a diagonal line of face extraction is maintained. But if the lag is increased to 8 m, the stability of the bottom-most block may be endangered. Under this condition, the tensile stress that would develop near the contact of the bottom-most block and the block immediately above this may lead to failure
