Heightening structure of gravity dam with limited combination of rear upper

The utility model discloses a gravity dam heightening structure with limited combination of a rear upper. According to the structure, an old dam body and a new dam body reach a certain combination proportion through interface treatment measures, structure measures, temperature control measures and the like, so that the effect of joint stress between the old dam body and the new dam body is guaranteed. Wherein the interface treatment measures mainly aim at an old dam body and are arranged on the old dam body; the structural measures are arranged on the combined surface of the old dam body and the new dam body; and the temperature control measure is arranged on the new dam body. The problem that the new dam body and the old dam body are difficult to connect into a whole or completely separate when the dam is heightened is solved; the method has the advantages that the old dam body and the new dam body are combined in a certain proportion, and the effect of combined stress between the old dam body and the new da