Arch–gravity dam

Overview

Arch–gravity dams are dams that resist the thrust of water by their weight using the force of gravity and the arch action.

An arch–gravity dam incorporates the arch's curved design which is effective in supporting the water in narrow, rocky locations where the gorge's sides are of hard rock and the water is forced into a narrow channel. Therefore, the span needed for the dam is also relatively narrow, and the dam's curved design effectively holds the water back while using less construction material than a pure arch dam or pure gravity dam. These dams are more reliable than arch dams. Typically, arch–gravity dams are built in canyon-like terrain, with the surrounding cliffs serving as supporting walls. An arch-shaped bank-fill design reduces the overall mass of the structure and the cost of construction compared to pure gravity dams. Arch dams and arch–gravity dams are most commonly used in hydraulic structures of more than 100 m in height.