Seepage-proofing connection structure of deep and thick covering layer dam foundation and gravelly soil core wall

The invention provides a seepage-proofing connection structure of a deep and thick covering layer dam foundation and a gravelly soil core wall. The covering layer dam foundation adopts two concrete seepage-proofing walls, and seepage-proofing of an upper portion rolling type rockfill dam adopts the gravelly soil core wall; connection of the gravelly soil core wall and the concrete seepage-proofingwalls is combination of a single-wall gallery mode and a single-wall inserting mode, and one pass of copper sheet waterstop is arranged at the connection position of the bottom of a concrete galleryand the top of a lower portion concrete seepage-proofing wall; the part, inserted in the gravelly soil core wall, of the upstream concrete seepage-proofing wall and the surrounding area of the concrete gallery are contact clay filling areas; and seepage-proofing geomembranes are arranged on the upstream side of the upstream side concrete seepage-proofing wall and the downstream side of the concrete gallery to reinforce see