Overtopping breach peak outflow approximation of embankment dam by using Monte Carlo method

摘要

The main goal of this paper is to develop an empirical relationship for estimating the peak outflow discharge of embankment dam breach due to overtopping flow. The main controlling parameter in the previously developed relationships is the reservoir volume behind the embankment dam. These relationships assumed that the whole reservoir volume becomes empty during the failure process and the area under the outflow hydrograph curve is equal to this volume. Conducted large scale physical models recorded that a remaining vertical head-cut in the upstream side of the embankment dam maintained even after the final breach formation. That means, the previously depended upon assumption is not true especially for embankments constructed from cohesive soils. The newly developed relationship accounts for the remaining vertical head-cut and the spelled overtopping flow. The Monte Carlo method was employed to calculate the area under the flow duration curve and consequently the development of the new formula. The new relationship gave more accurate results and reasonable outcomes as compared to actual previous case sttudies measured breach peak outflow discharges and the results obtained using previously developed formulae.