Overall construction method for belt straining beam dumbbell-shaped pile cap steel hoisting box cofferdam under complex sea conditions

The invention discloses an overall construction method for a belt straining beam dumbbell-shaped pile cap steel hoisting box cofferdam under complex sea conditions and belongs to the technical field of bridge cushion cap construction. The device comprises two symmetrically arranged steel hoisting boxes, wherein the steel hoisting boxes comprise wall plates, bottom plates, inner supports and bottoming concrete layers; two fish-bellied type truss girders are arranged between two steel hoisting boxes; a height difference adjusting cushion block is respectively arranged below two ends of the fish-bellied type truss girders; a pair of two-way brackets is arranged below the height difference adjusting cushion block; the two-way brackets are welded on the wall plates; front ends of the two-way brackets stretch into the bottoming concrete; straining beam bottom plates are arranged above the fish-bellied type truss girders. A combination of the fish-bellied type truss girders and bottoming two-way brackets embedded in