Experimental Study on Air- and Water-Inflated Double-Rubber Dams

A double rubber dam with the upper dam inflated by air and lower dam inflated by water is proposed in this paper. Large-scale physical hydraulic model tests are carried out to investigate the influence of the inflated air and water pressures, external water levels, anchoring distances, and cross-sectional perimeter ratios on the static response of the proposed structure. This study reveals that the optimum inflated air pressure in the upper dam is 0.25γwL1 and that in the lower dam is 0.45γwL1, where γw and L1 are the unit weight of water and perimeter of the upper dam. The optimum anchoring distance is 0.06L1, and the optimum perimeter ratio of the lower to upper dams is 0.9. Under the same external water depth, the material requirements of the proposed rubber dam are 105.8%–126% of the traditional rubber dam, and the tensile strength is 29.6%–48.8%. Considering the perimeter and tensile strength requirements, the total material costs of the air- and water-inflated double rubber dams are only 11.5%–24.2% of the traditional rubber dam.