Curtain Grouting for the Antamina Dam, Peru: Part 1—Design and Performance

A deep grouted cut-off was constructed as part of the 140 m high, concrete-faced rockfill dam at Antamina in the high Andes of Peru. Foundation conditions comprised upstream-dipping, contorted argillaceous rocks in the left abutment, varying to limestone with karstic solutioning in the right abutment. This potential for karst was of concern for ensuring the integrity of the dam cut-off and governed much of the rationale for defining curtain depths and for ensuring flexibility of grouting procedures. This, the first of two papers on the dam, concentrates on the design aspects of the curtain and foundation grouting philosophy. Curtain performance on impoundment to full height is then reviewed. The accompanying paper ("Curtain Grouting for the Antamina Dam, Peru: Part 2 — Implementation and Field Modifications") describes the curtain construction.