Design and Maintenance of Earth Dams [with Discussion]

THIS paper is intended to describe primarily the basic principles involved in the maintenance of earth dams. However, the executives and operators to whom such maintenance is intrusted, must be conversant with the underlying principles of design in order to guard against, interpret properly, and correct efficiently the misbehavior of any part of the structure. For this reason the paper will cover also the basic principles of design, at least to the extent necessary to describe the destructive forces acting on earth dams and the general provisions in the design and appurtenances provided to control them. With this information in mind, the operator will be in a better position to know just what steps to take should any feature of the structure prove inadequate. Unfortunately, to make a complete story, it will be necessary to review some principles which may be considered rather elementary to many. However, these will be passed over as quickly as possible. The first impression the writer desires to convey to you is that earth dams, properly designed and constructed, are safe structures, adequately adapted to the use to which they are put. However, in common with other types of important engineering works, earth dams have been known to have defects, ranging from minor faults to complete failure. In the following discussion, the writer will call attention to many possible defects in earth dams of varying degrees of importance. To line up these defects for simultaneous review gives a rather pessimistic color to earth dams and it is necessary therefore to state at the start that, in most cases, practically no defects of any nature appear and that the history of earth dams discloses that the percentage of serious defects is negligible. However, in spite of the good record which dams of this type have,