Time-Frequency Characteristics and the Influence Mechanism of the EMR from Coal with Different Joint Angles

Figure 14

Analysis of the main stress change of the district pillar caused by mining factors in Xinzhou Yao mine. (a) Numerical simulation model of Xinzhou Yao mine. (b) The district pillar at section I-I is subjected to vertical stress to produce plastic failure. (c) Roadway failure diagram.

(a)

(b)

(c)