ABSTRACT
Gravity dams on a soil (non-rock) foundation differ from those that are founded on rock by their expanded form of cross-section. In that way a greater weight of the dam has been provided, which should compensate for a 2-4 times smaller resistance of the foundation against sliding in relation to a rock foundation. Such an expanded form is also required due to the weaker strength characteristics of the soil foundation. For these reasons, the height of these dams is limited and usually does not exceed 40 m. This type of dams serves for slowing down of the watercourse aimed at creating conditions for water tapping, most often for the needs of amelioration and energetics, or else for increasing the depth of the river for the sake of providing conditions for navigation. They are usually built on rivers which are rich in water and are regularly carried out either as purely overflow dams, or else as combined dams – with an overflow and a non-overflow part. The overflow part can consist of one span or two or more individual spans if it is necessary to provide greater length for overflowing. Overflowing can take place freely, but more often there is a controlled overflow, when the overflowing spans are provided with gates, which open in case of need.
