Protection structure for existing upper-layer high-speed bridge pile foundation in subgrade filling of bottom layer road

The utility model discloses a bottom layer road subgrade filling protection structure for an existing upper layer high-speed bridge pile foundation, which comprises a thick steel plate, filling sand gravel, a concrete foundation, a connecting steel bar, a pile foundation and a straining beam, the thick steel plate is arranged on the periphery of the pile foundation to form a steel casing, and a reserved space between the thick steel plate and the pile foundation is filled with the sand gravel; the concrete foundation is arranged below the ground before roadbed filling along the periphery of the pile foundation, and connecting steel bars are pre-buried in the concrete foundation and used for erecting thick steel plates; the top of the structure is sealed by concrete, and the top surface is locally reinforced by steel plates; a distance is reserved between the top of the protection structure and the road surface. The device has the advantages of being simple in structure, easy to operate, wide in building mater