EXPERIMENTAL STUDY ON PIPING FAILURE OF NATURAL DAM

Abstract

The failure of natural dam may occur with a variety of failure modes which includes overtopping, seepage or piping, sudden sliding etc. Natural dams may fail due to seepage or piping because they have not undergone systematic compaction and they may have high porosities. In-depth knowledge of the mechanism of the dam failures by seepage or piping and measured data are still lacking. Extensive laboratory experiments are carried out to study enlargement of the pipe due to internal erosion and resulting outflow hydrographs by varying size of initial pipe, lake water level, lake water volume, slope and location of the pipe. This paper highlights limitations of simplified models used to predict outflow hydrograph due to piping failure of the dam based on experimental results and provides data set for the validation of numerical model. Experimental results show that the initial size, slope and location of pipes have significant effects on magnitude and occurrence time of peak discharge.