Research Article
Effect of the Initial Support of the Tunnel on the Characteristics of Rockburst: Case Study and Mechanism Analysis
Table 1
Stiffness score of support and surrounding rock in Micangshan tunnel [
28].
| | Type | Basic value/ A | Construction parameter/ B | Score |
| | Steel arch | 10 | Spacing (m) | A × (1/B) | | Strengthened steel arch | 15 | Spacing (m) | A × (1/B) | | Anchor | 1 | Anchor number per steel arch | A × B | | Shotcrete | 2 | Thickness (cm) | A × (B/10) | | Pre-grouting | 3 | Volumes (m3) | A × B | | Pressure release blasting | 2 | Number of boreholes | –A × B | | Surrounding rock mass | – | Grades (I-V) | I- 50；II- 40；III- 30；IV- 20；V- 10 |
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