ABSTRACT

Hydraulic structures, like other civil engineering structures, are built on construction ground, i.e. on the topmost formations of the earth’s crust. The well-known dam builder and French engineer, André Coyne,writes: “There is no structure that is so firmly bonded to the foundation as the dam is . . . In other words, the dam consists of two parts: an artificial dam, made by the man, and a natural dam – the foundation upon which it is founded and which, at the same time, also represents its continuation and surrounding. The more significant part, of these two, is the latter, even though it is invisible.’’ (André Coyne, Cours de Barrages, l’Ecole Nationale des Ponts et Chaussées, Paris, l939). Dam builders, of course, have always been aware of this fact; however, the variety of features of the foundation, until not long ago, has dictated the experiences, together with some empirical rules, to be used mainly in the calculations of dams.