Block model tests simulating the arching effect in the rock mass under the pull load of a rock anchor

Block model tests were conducted on a large-scale 2D test rig in the laboratory. The objectives of the tests were to demonstrate the arching effect in the block models and also the failure pattern of the models under the load of a rock anchor. The test results of two models with continuous horizontal joints and discontinuous vertical joints are presented in this paper. The digital image correlation (DIC) cloud images showed that load arches were formed in each layer of the blocks during testing. Solid confinement is extremely important to form the load arches. The load capacity of a rock anchor is much higher than the weight force of the failed rock mass body as long as the confinement is solid. The final failure of the model was in the shape of a crater and the failure surfaces follows a zig-zag path comprised of the horizontal and vertical joints.