Deformation-Induced Stability of Earthen Embankment Dams Subjected to Explosive Airblast Loading

Abstract

The purpose of this study was to investigate the deformation-induced stability of earthen embankment dams to explosive airblast loading. This study specifically investigated the effects of close-in explosive airblast loads on the downstream toe of a homogeneous earthen embankment dam composed of cohesive soils. Small-scale explosive airblast experiments on cohesive soils from a previous study were compared with numerical analyses. Finite-element simulations of airblast loading on a cohesive soil embankment dam were performed using multimaterial arbitrary Lagrangian Eulerian (MM-ALE) methods. Blast effects on varying reservoir levels and engineered drainage were investigated to determine the impact on dam stability. The airblast simulations created craters on the downstream slope and reduced the toe length. Although larger explosive masses removed more material, crater dimensions did not significantly increase with explosive mass due to energy loss in air. Circular slip surfaces intersected the crater and reduced stability for dams with no engineered drainage. A horizontal toe drain effectively lowered the phreatic surface away from the blast crater and increased structural stability. It was concluded that explosive airblasts posed a possibility of slope failure only for dams with no engineered drainage that were close to full reservoir capacity.