Abstract: By using independent researched and developed CM60/10 plane strain test-bed, combining with the triaxial servo test machine which playing the servo regulator performance, utilizing similar material simulation and numerical simulation, the characteristics of deformation and failure process of roadways with no support under high stress of  <1 state was analyzed. The results show that: 1) The destruction develops first from the center line of both sidewalls of roadway, after the local failure, there gradually formed a pair of “wedge” failure zone. In the stress relief area, surrounding rocks are destroyed in the form of zonal disintegration. Deep slip-line takes place from the tip point of the “wedge” destruction zone, which conforms to the logarithmic spiral line roughly; 2) In the process of roadway destruction, it is followed successively by three partitions of “wedge-shaped destruction zone,” “second destruction zone,” “transfixion instability zone”. The related studys show that during the different deformation period in this kind of ground stress, the failure control should focus on the sidewalls, the skewback and the roof except the control of the initial deformation of roof and floor; 3) Through the numerical simulation of the rock mass failure in  <1 state, the following results can be found: the vertical stress of the sidewalls is the “wave-like” distribution; the plastic damage zone is “partition evolution”; the vertical displacement is “jaggies-like” distribution. All of these are consistent with the physical experiments.

Key words: high stress; , <1 state, characteristics of deformation and failure, experimental research