Passage of flows through rock-earth dams during construction

Abstract

1. The experience with design, model investigations, and construction of rock-earth dams confirms the feasibility of their temporary flooding during construction, provided that general stability of the downstream slope in the flooded portion is ensured and that the overflow surface is protected against scour. 2. The most rational types of protection of flooded overflow surfaces, depending on the hydraulic flooding conditions, are the following revetments: a) with large selected stones; b) with large gabions having a stone porosity of not less than 45%, tied together into a single unit. The type and constructional features of the revetment should be selected by considering the need for discharging ice over the dam. 3. The success in the operation of each type of revetment depends on the degree and uniformity of compaction of the dam fill. 4. The effects of flooding of the dam during construction should be substantiated by means of model investigations carried out in order to discover the hydraulic conditions of the dam in all its flooding stages and to check the adopted types of revetments, and should be confirmed in accordance with the projected time for organization and execution of the construction work, to ensure the readiness of the dam by the time of flooding.