Development of Large Direct Shear Test Apparatus for Passive Bolt Reinforced Mass

Shear testing of large size rock mass in the laboratory is a tedious and challenging task. Difficulties further arise when testing is done with rock bolts. Complex interaction between intact blocks of mass, joint and bolts creates problems during shear testing. Hence, for testing of large rock mass with bolts, special technique and facilities are required. The present paper summarized the details of the development of a large sized direct shear testing facility for passive bolt-reinforced rock masses. A specially designed servo-controlled direct shear test apparatus having shear box of size 750 mm x 750 mm x 1000 mm has been fabricated in the Geotechnical engineering laboratory of IIT Roorkee. The normal loading capacity of the apparatus is 1500 kN while shear loading capacity is 2000 kN. To evaluate the performance of the apparatus, specimens of blocky mass were prepared and tested without and with bolts. The present paper discusses the details about the large direct shear apparatus and testing methodology.