Laboratory full-scale rock bolt testing: Analysis of recent results

Abstract

Rock bolting is a method used for rock reinforcement in underground mining and tunnelling. There is a large variety of different types of rock bolts with different support functions. The behaviour of a rock bolt in a rock mass depends on the function and material of the bolt itself, combined with the mechanical properties of the rock mass, deformation capacity, strength and level of stress. Testing of rock bolts in full-scale laboratory-controlled conditions is therefore of great importance. At the rock mechanics laboratory of SINTEF and Norwegian University of Science and Technology (NTNU) in Trondheim, a rock bolt test rig has been developed for full-scale testing for pull, shear and combination pull-shear tests. This paper describes the principles behind this quasi-static full-scale testing and includes the results and analyses of recent tests performed on different types of rock bolts. It also discusses the applicability of the test rig for rock bolt selection and rock support design.