Table 2 Neutral axis position of composite key strata model in drill hole 16 − 7.
From: Rock burst mechanisms induced by dynamic and static loading under composite key strata: a case study
Key stratum | Lithology | Thickness (m) | Overburden load (MPa) | Initial fracture length(m) | The overburden thickness controlled by the key stratum (m) |
|---|---|---|---|---|---|
Lower key stratum | Medium-grained sandstone | 36.8 | 0.83 | 72.3 | 36.8 |
Upper key stratum | Fine-grained sandstone | 34.6 | 1.00 | 72.4 | 57.2 |
Neutral axis position | ha=36.7 m, hb=34.7 m | ||||
