Design of Arch Dams

Arch Dam Design Arch dam design is in fact the design of a spatial shell that is curved in plan and transfers the load to the abutments and the foundation. In arch dam design, the majority of the loads caused by water are usually transferred horizontally to the side abutments of the dam, which results from the arch action. Its design is one of the most complex schemes, as the shape of the dam makes its calculations difficult, while the remainder of the load is transferred by cantilever action (similar to gravity dams) to the foundation at the base. Therefore, the behavior of this type of dam is an interaction between the arch behavior of the horizontal strips and the cantilever behavior of the vertical strips. The internal stresses in an arch dam are divided into two categories: stresses perpendicular to the radial vertical section of the dam (i.e., arch stresses), and stresses perpendicular to the horizontal section of the dam (cantilever stresses). By changing the flexibility and stiffness of the foundation and the walls, the load-bearing capacity of both the arch and cantilever actions changes. As a result of these changes in the stiffness and flexibility of the walls and the foundation, the location where tensile stresses form, and consequently where cracks occur in arch dams, changes. Since the construction of the first concrete arch dam in the world (Zola Dam) in France in 1854, and the first high concrete arch dam in the world (Hoover Dam, with a height of 221 m and a crest length of 372 m) in the United States in 1936, arch dams have received abundant attention from dam engineers thanks to their unique extra load-bearing capacity and self-regulating characteristic. In the field of dam construction throughout the world, more than half of the massive dams built worldwide with a height exceeding 200 m are of the arch dam type. In the western regions of China, a group of world-class arch dams with a height exceeding 300 m is under construction.