Okla. Admin. Code § 785:25-3-11
Current through Vol. 42, No. 8, January 2, 2025
As a guide for use by the Board and by engineers designing new dams, assessing the condition of existing dams or proposing modifications to existing dams, the following safety factors shall be utilized for:
| LOADING CONDITION | MINIMUM FACTOR OF SAFETY* |
| Steady seepage at emergency spillway crest | 1.5 |
| Rapid drawdown from principal spillway | 1.2 |
| Earthquake - reservoir at emergency spillway crest for downstream slope; reservoir at principal spillway for upstream slope | 1.0 |
| *The minimum factor of safety is calculated by the ratio of available shear strength to shear stress required for stable equilibrium. | |
| LOADING CONDITION | MINIMUM FACTOR OF SAFETY** (by hazard classification of dam) | |
| High and Significant | Low | |
| Principal spillway level | 2.25 | 2.0 |
| Inflow design flood at maximum pool level | 1.75 | 1.25 |
| Principal spillway level with earthquake | greater than 1.0 | greater than 1.0 |
| **These minimum factors of safety apply to the calculation of stress and the shear friction factor of safety within the structure of the rock/concrete interface and foundation. | ||
Okla. Admin. Code § 785:25-3-11