Open caisson shear key structure and construction method thereof

The invention discloses an open caisson shear key structure which comprises a plurality of shear key structure units arranged on the inner side of a first section of steel shell open caisson, and the shear key structure units are in lap joint with one another to form the open caisson shear key structure. Each shear key structure unit comprises an inclined face steel plate, a vertical face steel plate and a steel shell plate shaped like a Chinese character'ji ', the inner side of the first section of steel shell open caisson is concaved inwards to form a step-shaped notch with the small upper portion and the large lower portion, and the steel shell plates shaped like the Chinese character'ji' are fixed to the top and the upper portion of the step-shaped notch. The inclined surface steel plate is connected with the inner side of the first section of steel shell open caisson and the vertical surface steel plate through connecting rotating shafts, the upper end of the vertical surface steel plate is connected wit