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| Stability level | Assignment | Influence factor |
| Rock mass structure () | Geological structure () | Underground visible water () | Influence of groundwater on surrounding rock () | Impact of surrounding mining () | Adjacent empty space () | Project layout () | Pillar size layout () | Specification and shape of goaf () |
|
| Level I | 1 | Complete block structure | No fault and fold | No drenching trace | No water impact | The mining area is not affected by blasting operation | There is no adjacent empty area within the affected area | Reasonable | Code for pillar layout | θ < 1 |
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| Level II | 2 | Layered structure | Small fold influence | Visible water trace of rainfall | Less impact on water body | The impact of blasting operation in the mining area is small | There is no adjacent empty area within the affected area | More reasonable | There are pillars but they are not standard | 1 ≤ θ < 2 |
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| Level III | 3 | Structural fragmentation | Partial cutting or folding of fault has great influence | Heavy rainfall and drenching | General impact on water body | Large impact of blasting operation in mining area | The area and quantity of empty areas within the scope of influence are large, but they are scattered | Partially reasonable | There is no pillar or the layout is not standard and starts to be damaged | 2 ≤ θ < 3 |
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| Level IV | 4 | Loose structure | Fault penetrates rock mass | Rain in rainy season | Great impact on water body | The mining area has a great impact on blasting operation | The area of empty areas within the influence range is large, the number is large, and the adjacent areas are close | Less reasonable | There is no pillar or the layout is very irregular and seriously damaged | 2 ≤ θ < 3 |
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