Research on Plastic Zone Evolution Law of Surrounding Rock of Gob-Side Entry Retaining under Typical Roof Conditions in Deep Mine

Table 1

Classification standard of gob-side entry retaining under typical roof conditions in deep mine.

Number	Type	Lithologic	Thickness (m)
1	Thin immediate roof	Shale, mudstone, sandstone, and so on	0.5–3.0 m
2	Thick immediate roof	Shale, mudstone sandstone, and so on	>3.0 m
3	Thick-hard roof	Sandstone, limestone, glutenite, and so on	>5.0 m
4	Compound roof	Shale, mudstone, siltstone, and so on	The thickness of a single rock layer is less than the mining height, and there is no thick-hard rock layer in the range of 5.0–8.0 m and above