Experimental study on hydrodynamic interaction between dam-break waves and circular pier

Abstract

This paper focuses on the hydrodynamic interaction between dam-break waves and circular pier. Firstly, a series of dam-break waves under dry-bed and wet-bed conditions were conducted, the evolution of wave front profiles are obtained experimentally. Then, experimental studies on hydrodynamic interaction between these dam-break waves and a circular pier were carried out systematically. After that, the pressures and their vertical distributions on the front, back and lateral side of the circular pier are obtained and analyzed in detail. In which, sudden rise of pressures on the front side, obviously oscillatory pressures on the back side, and negative pressures on the lateral side are observed. Furthermore, the forces and moments on the circular pier are presented, and their characteristics are explored. Among which, the maximum force and moment occur in the impulse stage when there are fluctuations upstream of the wave front, otherwise they occur in the quasi-stationary stage. In addition, the corresponding dimensionless coefficients are obtained and their evolutions are revealed elaborately. Finally, the calculation formulas for maximum force and moment on circular pier, considering the variation of wave front profile, are proposed, and related coefficients are suggested. This study could provide reference for the improvement of calculation method.