In order to understand the failure mechanism of the host rock for the model excavations, the stress distribution is solved first. When the state of stress in rock around the opening is calculated based on the theory of elasticity, for the circular and elliptical openings subjected to uniaxial or biaxial stress states, the stress distributions in the host rock are provided by well- known analytical solutions. For the inverted U-shaped opening, the stress distribution is obtained though finite element analysis