The invention discloses an installation method of a steel
cofferdam for reinforcing a bridge
underwater structure. The method is characterized in that by cleaning a stand column, arranging an anti-skid
washer, installing a hoop, assembling a
counterforce frame, fixing
counterforce chain blocks, lowering the steel
cofferdam, arranging cross beams and longitudinal beams, installing jacks and performing symmetrical pressing, rapid pressing installation of the steel
cofferdam for reinforcing the bridge
underwater structure is completed; the hoop and the
counterforce frame are assembled into a whole through buckles, the counterforce chain blocks are connected with the stand column to form an inverted-triangle counterforce
system, and the positions of the jacks are determined according to the specification of the steel cofferdam. The method has the advantages that construction is fast and convenient, steel cofferdams with different diameters can be pressed in place in one step, the operationis simple and easy to control, the self-counterforce
system and hoisting equipment are integrated, large hoisting equipment is not needed, installation and detachment are easy, the space requirementis low, and the problem that as tie beams exist between a
pier and a
pile foundation, operation is difficult is solved; hoisting chain blocks can be used for lowering and adjusting the steel cofferdamand can also be used for lowering materials and formworks in the later stage, and the construction efficiency is greatly improved.