Vortex-induced vibration analysis of submerged floating tunnel tension legs

Abstract

Considering the influence of axial and transverse vibration of tension legs of submerged floating tunnel, the non-linear vibration equation of the tension leg under the action of vortex-induced excitation is derived and solved numerically by Galerkin and Runge–Kutta methods. The results show that the vibration amplitude and frequency of tension legs under the action of vortex-induced excitation are related to the natural frequency of tension legs. Due to water damping, the vortex-induced vibration response of tension legs in submerged floating tunnel is lower than that of the tension leg in air; the shorter the length of the tension leg, the higher will be the current velocity needed to produce vortex-induced resonance; the larger the initial tension of the tension leg, the faster will be the current velocity needed to generate vortex-induced resonance; the transverse pulse force increases with an increase of the initial tension and the outside diameter of the tension leg, and decreases with an increase of the length of the tension leg.