Method for assembling and sinking hydraulic structure in place in moving water through block-assembled hydraulic structure

The invention discloses a method for assembling and sinking a hydraulic structure in place in moving water through a block-assembled hydraulic structure. Prefabricated components of the hydraulic structure are assembled and arranged on the downstream of an original structure through a horizontal installation platform. The horizontal installation platform comprises a door-shaped steel truss, a buoyancy base, a traction assembly and a hoisting assembly. During construction, (1) an electric hoist is used for hoisting the first prefabricated component, after the first prefabricated component is conveyed to the sinking position, the first prefabricated component is connected with a manual hoist, then connection between the electric hoist and the prefabricated components is released, and load transfer from the electric hoist to the manual hoist is completed; (2) the second prefabricated component is hoisted through the electric hoist and conveyed to the position over the first prefabricated component; (3) the secon