Scaling the failure of concrete gravity dam subjected to underwater explosion shock loading

Abstract

The small-scale model test is the major affordable approach to experimentally investigate concrete gravity dams against underwater explosions. However, results of the small-scale model should be properly converted to the prototype, which requires the knowledge of scaling law. This study presented the scaling of failures of concrete gravity dams against underwater explosion shock loadings through small-scale centrifuge tests and numerical simulations. The dimensional analysis-based scaling law, which was essentially the geometrical scaling law for dams and the well-known Hopkinson scaling law for underwater explosion shock loadings, was employed. According to the scaling law, a numerical scheme comprising six numerical simulations with geometrical scaling factors β = 1, 1/10, 1/30, 1/50, 1/80, and 1/100 was devised. Results demonstrated that dams with different scaling factors exhibited essentially the same failure mode, i.e., the structural bending-induced tensile failure mode. On this basis, it was discovered that most dam dynamic responses followed the scaling law. It was also found that when the strain-rate effect was pronounced, such as in dam tensile stresses and tensile failures, the scaling law was violated. Despite the incomplete scaling law, the small-scale model tests can be used to identify the most vulnerable positions of the dam prototype.