Strength of Models of Rock with Intermittent Joints

The problem of predicting the strength of an in situ rock mass containing a complex pattern of jointing is one commonly met in engineering practice. Although simplified analytical approaches to the problem exist, e.g., Bray (2), John (13), Jaeger (12), and Lajtai (17), further progress in its study is hampered by the impracticability of carrying out large numbers of in situ tests on rock masses to failure. It seems that one means by which this difficulty may be partly overcome is to test simulated rock masses in the laboratory.