Runup and inundation of non-decaying dam-break bores on rough uniform slopes

Abstract

The dam-break mechanism has been frequently utilized in laboratories to generate bores and investigate the associated swash flows. However, as the bore length depends on the length of the dam-break reservoir, most of the published data cannot be comparable because they were not on the same basis in terms of the bore length. This study investigated experimentally non-decaying dam-break bores on smooth and rough slopes. We first compared the measured free surface elevations, runup heights, and inundation depths against published experiments for a non-decaying bore with the same bore strength. The comparison revealed satisfactory agreements between the two experiments. Then, the present data with various bore strengths were utilized to develop empirical formulas for predicting maximum runup heights and inundation depths. The reduction factors were introduced to compare the measured runup heights and inundation depths for bores on rough and smooth slopes to assess the effects of slope roughness. The empirical runup and inundation formulas for smooth slopes were extended to rough slopes used in this study by incorporating corresponding reduction factors. The extended formulas showed the accuracy and applicability for predicting runup heights and inundation depths within an error of about 15 % and with correlation coefficients of around 0.99.