Ice layer bearing capacity improving method for on-ice construction of river-crossing bridge in severe cold area

The invention relates to an ice layer bearing capacity improving method for on-ice construction of a river-crossing bridge in a severe cold area, which comprises the following steps of: before river water is frozen, inserting and driving a row of steel pipe piles around a construction area in a river respectively, and welding flat connecting rods between parts of adjacent steel pipe piles, which are higher than the water level; after the river water is frozen and the detected thickness of an ice layer meets the construction passing requirement, water retaining clay bags are stacked on the outer sides of the steel pipe piles in each row, and a space with the periphery closed is defined by the construction area; and a stiffening net is bound on the natural ice surface in the construction area, the periphery of the stiffening net is fixedly connected with the steel pipe piles and the parallel connectors, then water is injected into the construction area for freezing, reinforced ice is formed, and construction is