Second dam structure without pump drainage during operation period and for temporary pump drainage during maintenance period and applying method of second dam structure

The invention relates to the field of water conservancy and hydropower project flood discharge and energy dissipation design, and discloses a second dam structure without pump drainage during the operation period and for temporary pump drainage during the maintenance period. The second dam structure comprises a second dam body, a plurality of drainage holes are formed in the upstream dam surface and the downstream dam surface of the second dam body from top to bottom correspondingly, a horizontal foundation drainage gallery is arranged at the bottom in the second dam body, the drainage holes all communicate with the foundation drainage gallery, a water collecting well is arranged on the position, on the lower part of the foundation drainage gallery, in the second dam body, the water collecting well communicates with the foundation drainage gallery, a vertical pumping well is arranged between the water collecting well and the top of the second dam body, and a reserved pit for installinga water pump base is for