It is shown that elastoplastic stress field of circular roadway
which is given by the classic plasticity mechanics
is not correct. Therefore
it affects rationality of stability evaluation and support design of circular roadway. Based on the accurate analytic solution obtained by the new solving system of plastic mechanics
failure zone
relationship between stratum residual strength and support pressure of circular roadway are studied in isotropic and homogeneous stratum. The following results are obtained: (1) Failure zone increases as mining depth increase
which is basically a linear relation. (2) Relationship among support pressure
depth of roadway
strength and residual strength of surrounding rock
Poisson's ratio and bulk density is established. These results will be of great help to support design.