Experimental Investigations on the Spillway Section Shape of the Breaching Process of Landslide Dams

Abstract

Excavation of spillways at dam crest is one of the most commonly utilized and effective engineering practices to mitigate the risk of landslide dams. The influence of spillway section shape on the breaching process of landslide dams was examined in this research via the flume tests using dams with one triangle and two trapezoid spillways. A smart and green testing system was proposed to simulate the overtopping breach process of landslide dams. The experimental results showed that the triangle spillway had the best performance to reduce the peak breach discharge and delay the occurrence time of peak breach discharge. Due to the worst seepage erosion and the formation of scarp, the peak breach discharge of the wide trapezoid spillway was the largest and occurred most quickly. The performance of the deep trapezoid spillway was between those of the triangle and wide trapezoid spillways. Considering the inconvenience of triangular spillway excavation for rapid construction, the cross-section shape of a deep trapezoid was suggested in the excavation of spillways.