Optimization and Practice for Partition Pressure Relief of Deep Mining Roadway Using Empty-Hole and Deep-Hole Blasting to Weaken Coal

Table 2

Division of stress segment and risk.

Name	Critical value		Stress relief
Region ()			None
General-risk region ()		28.8 MPa	Stress relief
Medium-risk region ()		34.56 MPa	Stress relief
High-risk region ()		38.4 MPa	Stress relief