Fig. 21
The overall change trend diagram of surrounding rock energy. This picture shows the full-cycle evolution law of the energy-plasticity zone of the roadway surrounding rock, in which the influence range of the plasticity zone of the roadway surrounding rock is mainly concentrated in the area from 80m before the meeting of the back-mining face to 20m after the meeting, which is shown as the orange area in the picture; the influence range of the energy of the roadway surrounding rock is obviously larger than the plasticity zone, and the surrounding rock is accumulating energy under the action of the accumulated elastic strain energy, and according to the above picture of the trend of the energy change. According to the energy change trend graph above, the energy change is also obvious after 20m of meeting, and there is a potential plastic damage zone under the action of accumulated elastic strain energy of the tunnel surrounding rock, which is shown as blue area in the graph.
