Dr.-Ing. K. Broich

1. Determination of initial conditions for dam erosion due to overtopping and possible integration into a probabilistic design concept Dr.-Ing. K. Broich University of the Federal Armed Forces Munich

2. Initial conditions • Case study • Monte Carlo simulation University of the Federal Armed Forces Munich

3. dH/dt dz/dt Q Initial period depletion t University of the Federal Armed Forces Munich

4. Flood wave • Initial breach • Initial water depth • Outlet • Overtopping • Dam coverage University of the Federal Armed Forces Munich

5. University of the Federal Armed Forces Munich

6. Proposal : Safety factor for Overtoping failure of earthen dams = Scaling factor on design flood wave needed to start erosion University of the Federal Armed Forces Munich

7. Initial conditions • Case study • Monte Carlo simulation University of the Federal Armed Forces Munich

8. Test case : 1 . Calculation with scaled design flood wave HQ1000 and initial water depth at flood water level 2 . Calculation with unscaled PMF flood wave and initial water depth at dam crest University of the Federal Armed Forces Munich

9. H V University of the Federal Armed Forces Munich

10. University of the Federal Armed Forces Munich

11. University of the Federal Armed Forces Munich

12. Initial conditions • Case study • Monte Carlo simulation University of the Federal Armed Forces Munich

13. University of the Federal Armed Forces Munich

14. Load variables for overtopping • Failure mode • Flood wave *) • Initial water depth *) bivariate variable -> volume University of the Federal Armed Forces Munich

15. (Hable,2001) University of the Federal Armed Forces Munich

16. The probabilistic method using a Monte Carlo simulation (Hable, 2001) can be extended to calculate the probability of an overtopping failure. The failure condition has to be substituted by the mentioned „CIRIA-condition“. University of the Federal Armed Forces Munich