Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway

<div>Vertical stress distribution map of overburden structure before and after excavation when roadway is located in the fracture line of key block. (a) Before roadway excavation (unit: Pa). (b) After roadway excavation (unit: Pa).</div>

Advances in Civil Engineering

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Figure 5

Figure 5: Structural Mechanical Characteristics and Instability Law of Roof Key Block Breaking in Gob-Side Roadway 