列车交会下高铁隧道衬砌赋水裂缝气动效应OA

As a typical type of lining defect,water-filled cracks may experience a sudden increase in internal pressure due to the coupling effect of water-air two-phase media when pressure waves generated by train operation propagate within them,thereby exacerbating crack propagation.To investigate the variation in aerodynamic effects within water-filled cracks,the successive random accumulation method was employed to reconstruct the rough crack surface.Combined with the volume of fluid method and the RNG k-ε turbulence model,a multiphase flow coupling model of air,tunnel and water-filled crack was established.The variation in aerodynamic effects inside the crack under train meeting conditions was analyzed and the influence of the crack's longitudinal distribution position and train speed on these effects were explored.The results indicate that the aerodynamic effect is the most significant when the crack is located in the middle of the tunnel.Increasing vehicle speed makes both the peak pressure and the peak pressure gradient in the crack increase following a power function.The crack tip is identified as a pressure concentration zone,where the peak pressure and pressure gradient are higher than those at the crack entrance.Specifically,for a crack located in the middle of the tunnel,the positive and negative peak pressures at the crack tip can reach 1.26 and 1.33 times those at the entrance,respectively,while the positive and negative peak pressure gradients can reach 1.55 and 1.02 times,respectively.Water movement inside the crack is the main cause of pressure variation at the tip,showing a positive correlation with the pressure magnitude at the tip.This study clarifies the pressure response mechanism of water-filled cracks under aerodynamic loads during train meetings,providing a theoretical basis for defect assessment and maintenance design of high-speed railway tunnel lining cracks.