Multiple Arch Dam
A multiple arch dam is a variation of an arch dam, except the structure features repeated or contiguous arches that slope at about 45 degrees to the horizontal with the arches being carried on a parallel buttress wall. Structurally, therefore, it integrates the design of both a buttress dam and an arch dam.
A few advantages of a multiple arch dam over an arch dam are that multiple arch dam is typically more lightweight and requires less material to build. The foundation of a multiple arch dam does not have to be as solid as that of an arch dam and the design is suitable for a wide range of canyon types.
The multiple arch dam design is not as widely used as it once was. This is evidenced by the fact that none have been built in the U.S. since 1962.