Damage behavior of concrete members subjected to underwater contact explosion

Abstract

In order to investigate the damage mechanism of dams subjected to underwater contact explosion, firstly, an experimental program was conducted with six concrete slabs and two explosive quantities. The test results showed that the diameter and depth of the crater on the front and back surface of the concrete slab increased with increasing explosive quantity with radial and circular cracks generated. Three different concrete material models were tested and it was found the CDP model was most suitable in simulating concrete subjected to underwater explosion. The calibrated models were used to conduct parametric studies to study the effect of explosive quantity, slab thickness, and transferring medium (water or air). Numerical analysis results showed that the diameter and depth of the crater on both the front and back surface of the concrete slab decreased with increasing slab thickness and decreasing explosive quantity. In addition, the damage caused by the air contact explosion was smaller and more concentrated in the detonation center compared with underwater contact explosion. Finally, a gravity dam and an arch dam were modeled to study the effect of detonation depth and water level on the damage distribution pattern of the dams. Based on the results, recommendations were provided for the anti-explosion protection design of hydraulic structures.