ABSTRACT
The analysis of the stability of the surrounding strata, therefore, aims at seeing if the stress has reached and exceeded the limiting strength, in other words, if there is a plastic break in rock. The plastic stress point and value are given when a certain point in the rock meets Druck-prage-cap criterial in the analysis in the numerical simulation, then the process and the scope of the deformation and break of the surrounding strata can be identitied. At the beginning period of the solid coal way heading, the plastic zone of the surrounding strata is symmetrical to the vertical axis of the way. The plastic zone of the way bottom resembles that of the roof. The plastic zone distribution of the surrounding strata of the gate way is completely different from ordinary tunnels such as the homogeneous surrounding rock tunnels under the in-situ stress.
