Open-cut river-crossing tunnel constructed by cofferdam method in segmented manner and construction method thereof

The invention is applicable to the technical field of municipal engineering, and provides an open-cut river-crossing tunnel constructed by a cofferdam method in a segmented manner and a construction method thereof. The open-cut river-crossing tunnel comprises a conventional section tunnel, a post-pouring section tunnel and a closure section tunnel, wherein the closure section tunnel is positionedin the center of a river; the conventional section tunnel and the post-pouring section tunnel are sequentially arranged on two sides of the closure section tunnel at intervals; and the open-cut river-crossing tunnel is not provided with any deformation joint below the river. By the post-pouring section tunnel and the closure section tunnel, the problem of water resistance of the river-crossing tunnel is solved. Moreover, according to the construction method of the open-cut river-crossing tunnel, the open-cut river-crossing tunnel is constructed in two dry seasons by the cofferdam method in twostages, about half of a r