The dynamic-instability of radial gate was always due to the instability of arm under dynamic loading action, the security of gate spillway was dominated by the dynamic stability of arms.

• 摘要弧形闸门的动力失稳往往是由于支臂在动力荷载作用下丧失动力稳定的，支臂的动力稳定与否控制着整个水闸的泄洪安全。