Rock Resistant Factor "K" in Circular Pressure Tunnel by the Plastic Harding Theory

This paper presents a formular of rock resistant factor "K" in a pressure tunnel with circular cross section, whether the rock masses is situated in elastic or plastic states. The authors derived this formular by a model of linear strain-harding material of plastic theory on the bases of test results of rock masses. For this formular may be derived either in elastic or plastic theory, and it is widely useful and considerably economic value for application.