Effect of the intermediate principal stress on the fracture of brittle rock.
Rock Mechanics--theory and Practice Proc 11th Symp on Rock Mechanics Univ of California :13 pages
The primary conclusion of the study is that the effect of the intermediate principal stress on the fracture strength of brittle rock (when the failure initiation models are specified by equations given) is not large enough to warrant its consideration in engineering calculations involving the behavior of brittle rock under multiaxial stress conditions. This conclusion is justified without qualification when all the principal stresses are compressive.
OP; Conference/Symposia Proceedings
Rock Mechanics--theory and Practice Proc 11th Symp on Rock Mechanics Univ of California