Chainage | By relation proposed by Hoek and Brown [42] | By relation proposed by Grimstad and Barton [44] | ||||
σc/σΘ | For Roof | For walls | σc/σΘ | For Roof | For walls | |
0+876 - 1+000 | 7.67 | Stable | Stable | 12.97 | Medium stress, Favourable stress Condition | Medium stress, Favourable stress Condition |
1+000 - 1+600 | 2.41 | Severe spalling | Minor (Side wall) spalling | 5.00 | High Stress, Usually favourable to Stability | |
1+600 - 2+000 | 1.94 | Heavy Support Required | 3.62 | Moderate Slabbing after 1 hour | ||
2+000 - 2+400 | 1.82 | Severe spalling | 3.31 | |||
2+400 - 2+800 | 1.76 | 3.16 | ||||
2+800 - 3+200 | 2.24 | Severe spalling | Minor (Side wall) spalling | 4.48 | High Stress, Usually favourable to Stability | |
3+200 - 3+600 | 2.28 | 4.60 | ||||
3+600 - 4+000 | 8.97 | Stable | 5.84 | Medium stress, Favourable stress Condition | ||
4+000 - 4+400 | 8.32 | 5.07 | ||||
4+400 - 4+800 | 7.91 | 4.63 | ||||
4+800 - 5+200 | 8.16 | 4.88 | ||||
5+200 - 5+600 | 2.19 | Severe spalling | 4.31 | High Stress, Usually favourable to Stability | ||
5+600 - 6+000 | 6.96 | Minor (Side wall) spalling | 3.73 | Medium stress, Favourable stress Condition | ||
6+000 - 6+600 | 7.61 | Stable | 4.33 | |||
6+600 - 7+000 | 8.68 | 5.48 | ||||
7+000 - 7+200 | 11.80 | Stable | 10.96 | |||
7+200 - 7+506 | 3.91 | Minor (Side wall) spalling | Stable | 16.44 |