Table 8 Comprehensive assessment of rock burst risk in the tunnel.
Route mileage | Tunnel length (m) | Buried depth (m)/the maximum stress of the surrounding rock (MPa) | Lithology | Development status of structural planes | Energy method | The stress-strength ratio method | Comprehensive analysis |
|---|---|---|---|---|---|---|---|
DK243 + 255–DK246 + 255 | 0–3000 | 3–390/1–21 | Granite, biotite granite, faults | Fault, development of Level III and IV structural planes | No rock burst | No–weak rockburst | No–weak rockburst |
DK246 + 255–DK246 + 755 | 3000–3500 | 390–580/18.3–29.5 | Sandstone and slate | Fault, development of Level III and IV structural planes | No–moderate rockburst | No–weak rockburst | No–weak rockburst |
DK246 + 755–DK247 + 255 | 3500–4000 | 580–808/29.5–35.9 | Sandstone, quartz sandstone | Development of Level II and III structural planes | Weak–moderate rockburst | Weak–moderate rockburst | Weak–moderate rockburst |
DK247 + 255–DK247 + 755 | 4000–4500 | 650–750/27.5–34.5 | Sandy slate, Calcareous slate | Development of Level II and III structural planes | Weak–strong rock burst | Moderate–strong rock burst | Moderate–strong rock burst |
DK247 + 755–DK248 + 155 | 4500–4900 | 577–585/26–27.5 | Granite, sandy slate | Development of Level III and IV structural planes | No–moderate rockburst | Weak–moderate rockburst | Weak–moderate rockburst |
DK248 + 155–DK249 + 005 | 4900–5750 | 585–685/26.5–27.5 | Granite and slate | Development of Level II and III structural planes | Weak–strong rockburst | Moderate rockburst | Moderate rockburst |
DK249 + 005–DK252 + 255 | 5750–9000 | 600–750/24–35 | Slate, calcareous slate, sandy slate | Development of Level II and III structural planes | Weak–strong rockburst | Moderate rockburst | Moderate rockburst |
DK252 + 255–DK253 + 005 | 9000–9750 | 380–585/17.5–25.5 | Sandy slate, slate | Development of Level III and IV structural planes | No–weak rockburst | Weak rockburst | Weak rockburst |
DK253 + 005–Dk254 + 925 | 9750–11,670 | 80–380/2.7–18 | Slate, quartz sandstone | Development of Level III and IV structural planes | No rockburst | No rockburst | No rockburst |
