Analysis of geological factors of surrounding rock deformation of abandoned roadway under high internal pressure.

Abandoned coal mine roadways are used to construct compressed air energy storage (CAES) caverns. However, the surrounding rock of the roadway is subjected to high internal pressure, which changes the stress state of the surrounding rock and causes rock deformation that directly affects the roadway stability. In this study, numerical simulation software FLAC3D was used to calculate the displacement and plastic zone volume of surrounding rock under 5–10 MPa internal pressures. Effects of buried depth, surrounding rock grade, and in situ stress state on surrounding rock deformation under high internal pressure were analyzed. Results show that the displacement and plastic zone volume of the surrounding rock decrease with the increase in buried depth, and the deformation of shallow surrounding rock is greater than that of the deep surrounding rock. The deformation of grades IV and V surrounding rocks is greater than that of grades I, II, and III surrounding rocks. The surrounding rock deformation is the largest under σ_v > σ_H > σ_h, followed by σ_H > σ_v > σ_h, and the smallest under σ_H > σ_h > σ_v. The research results play an important role in the safe construction of CAES caverns on abandoned roadways. [ABSTRACT FROM AUTHOR]