PURPOSE: To improve the antiseismic feature of a vertical-shaft pump by making a ratio between the length from the fixed end of a pumping pipe to the fitting section of a bracing device and the length from the fixed end to the free end of the pumping pipe within a range of 0.6W0.8.

CONSTITUTION: In order to suppress the deflection of a pumping pipe 5, a bracing device is provided in the middle of the pumping pipe 5 and a resonant phenomenon is avoided. That is, a bracket plate 9 of the bracing device is provided on the wall surface of a water tank 6, and a pumping pipe 4 penetrates the hole 9a of the bracket plate 9 and a damping plate 10 is fixed on the bracket plate 9 so that the hole wall of the hole 10a of the damping plate 10 is brought into contact with the surface of the pumping pipe 4 to suppress the vibration. Furthermore, a ratio between the length from a cantilever support section to the fitting section of said bracing device and the length from said cantilever support section to the lower free end of the pumping pipe is set within a range of 0.6W0.8, thus the effect on the vertical-shaft pump during an earthquake can be prevented.