LAUSR

The criteria of failure and limiting state, widely used in strength assessment of rocks and building materials, are considered. The two-dimensional computer model is presented for deformation of cement lining in a cemented cased hole in rock mass under the action of internal pressure from the casing and external pressure from rock mass. The model has a number of science-based and experimentally proved strength criteria for determination of failure behavior and potential damaged zones in cement lining. A series of stress-strain analyses of cement lining is performed with varied geometrical parameters and stresses. The criticality of local and nonlocal failure criteria is analyzed. By comparing equivalent stresses, six failure criteria are selected and recommended for estimation and prediction of load resistance of cement lining.