Abstract—The Great East Japan Earthquake, which occurred on March 11, 2011, inflicted serious damage on civil and architectural structures in northeastern Japan. The tsunami generated by the earthquake washed away the superstructures of road bridges. The damage caused by this disaster had a strong impact on the design of road bridges. Against this background, numerical simulation is expected to become an important tool to evaluate the tsunami force acting on bridge structures. This study aims to apply explicit moving particle simulation (E-MPS), which is one of the particle methods, to the three-dimensional (3D) simulation of fractures of a bridge superstructure. A dam break problem with a floating rigid body is solved by E-MPS, and the results are compared with those obtained by the corresponding experimental approach to verify the developed E-MPS code. The tsunami run-up and simulation of a bridge being washed away are implemented by the E-MPS, and their realistic visualization results are demonstrated by the help of marching cube method.