Stability Correction Calculation of New Debris Flow Grille Dam Considering Permeation

Abstract

In current studies, when calculating the stability of a permeable dam under half-full or full reservoir conditions, seepage force has not been considered. Based on the stability calculation equation of a new debris flow grille dam structure, combined with the accumulation seepage model and the Bernoulli principle, the simplified expression of seepage force was derived, and its effect on the dam body was found to be equivalent to the overturning moment; thus, the original calculation equation was corrected. The effect of changing the internal friction angle on the stability was analyzed, making the corrected equation universal and applicable. The verification results showed that the overturning stability coefficient of the blocking dam was positively correlated with the internal friction angle. Compared to the original calculation equation, the anti-overturning stability coefficient of the blocking dam was reduced by about 44.5% on average after considering the seepage force; the attenuation amplitude increased with the increase of the friction angle in the accumulation, which was closer to the actual stress situation.