Construction method for constructing road on dredger fill soil foundation and subgrade strengthening structure formed by adopting construction method

The invention discloses a construction method for constructing a road on a dredger fill soil foundation and a subgrade strengthening structure formed by adopting the construction method. A subgrade structure is preliminarily formed by combining sludge filled film bags with a three-dimensional compound drainage network and water drainage of a water-collecting well and forming a hard shell structure on an upper dredger fill soil layer; then, deep plastic drainage plates are driven, a sand layer is laid, a pressure is exerted to a film bag layer and the dredger fill soil foundation by presetting an excessive pre-load so as to further promote drainage of filled sludge soil moisture in the film bags and drainage of moisture of the dredger fill soil foundation, and reinforcement of the sludge filled bags and deep foundation soil is achieved simultaneously. After the foundation deforming conditions meet the engineering requirements, the load is released, an upper-portion subgrade and a pavement are constructed. 本发明公