Research Article
Rock Mass Classification for Columnar Jointed Basalt: A Case Study of Baihetan Hydropower Station
Table 5
Weak plane tightness classification.
| Weak plane tightness | Tight | Relatively tight | Moderate tight | Relatively loose | Loose | Weak plane opening (mm) | <0.5 | 0.5~3 | 3~5 | 5~10 | >10 | Columnar joints opening (mm) | 0 | <0.5 | 0.5~1 | 1~3 | >3 | Geological condition | Unweathering | Slightly weathering~unweathering | Weak weathering~slightly weathering | Weak weathering | Weathering |
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