High-strength anti-seepage structure for expansion joint on surface of dam body

The utility model relates to the technical field of dam body expansion joint engineering, in particular to a high-strength anti-seepage structure for an expansion joint on the surface of a dam body, and solves the technical problem that the configuration of the expansion joint of the dam body in the prior art does not have a more suitable technical scheme for stress balance and waterproof effect. The method specifically comprises the steps that a telescopic groove with the T-shaped section is formed in a dam face concrete layer; the telescopic groove comprises a longitudinal gap section and a transverse gap section; the main body structure of the telescopic piece can be arranged in the telescopic groove; the part, located on the longitudinal gap section, of the telescopic piece body structure can be filled with polyurethane foam. Two groups of dowel bars can be prefabricated on the part, located on the transverse gap section, of the telescopic piece main body structure, and a polyethylene rod is filled betwee