definition
strict definition
gravity dam
A dam that relies primarily on its own substantial mass to resist pressure from the water behind it.
A gravity dam is a barrier in a moving channel of water which depends on its own great mass to resist the pressure of water behind it. Unlike an arch dam, it does not rely primarily on upstream curvature to transfer water loads to the abutments through arch compression.
The weight and mass of the barrier provide its principal resistance to the water load. An arch dam instead derives substantial resistance from its curved form.
An arch-gravity dam combines arch action with substantial mass. The relative structural action distinguishes these dam forms.