Question

Write short note on the following Galleries in gravity dams

Answer 1

The normal function of a gallery is to provide access for inspection purposes, to monitor the behaviour of the dam, and to carry out remedial work if required. It must therefore be of sufficient height to permit easy movement of personnel and minor equipment, commonly 2.13m but varied to suit construction methods. The width is usually 1.5m but should be related to the function of the gallery. Wide opennings induce quite high local stresses with consequent cracking of the concrete. Spiral staircases can link other galleries, ventillation and pipes in quite a small shaft.

Circular shafts are the most desirable, with a removable floor covering drainage, but it is harder and more expensive to form. Rectangular galleries require greater amounts of reinforcement. Galleries also should be well lit and ventillated.