The comparative analysis of the stress-strain state in the circuit and in the vicinity of a single generation of circular and arched curves of elastic and non-linear strain diagram types of rocks. Graphic dependences were obtained by the finite element method, reflecting the nature of the stress-strain state. The actual values of the tangential stress concentration factor on the circuit were obtained using non-linear functions.
Method of excavation support and tunnel lining design is worked out. Stiffness of soil strata is considered as nonlinear elastic. The problem is solved in plane strain condition according to elastic theory. The distribution of average load on excavation support is given.