Considering vertical cantilever sectionsm of unit width it is a simple matter to compute vertical stresses on horizontal planes for the cases of reservoir empty and reservoir full. In general, efforts are made to avoid tensile stresses in the concrete for normal loadings. Compressive stresses are not usually high in gravity dams.

The usual analysis stresses normal to horizontal planes are assumed to have a linear trapezoidal distribution. Finite element methods show the stress distribution to be as in the figure.

It is significant that the maximum stresses do not occur at the downstream toe, and there may be tension rather than compression at the upstream heel. However, there is similarity between the two methods. It is important to check the distribution and intensity of stress around galleries and other openings in the dam and to provide adequate reinforcement to prevent propagation of cracks from points of high stress concentration.

(C) Thomas, Henry H. The Engineering of Large Dams