Physical characteristics of the performance and increase of the reliability of functioning of overflow dams with a {open_quotes}second limit state{close_quotes} of the rock foundation
The main danger for the stability of high-head overflow dams having large safety factors is related to unfavorable processes in two zones of the foundation - near the upstream and downstream sides of the dam - due to fracturing of the rock foundation next to the dam by flood discharges. Fracturing of the toe of a dam, especially a gravity-arch dam, is accompanied by an increase of shear stresses in the rock under it to values exceeding the design values, and owing to fracturing of the rock below the dam foundation deformation movements of the dam toward the lower pool increase markedly, moreover, the greater amount, the more considerable the depth of fracturing below the dam foundation. As a result the tensile stresses in the rock in front of the dam increase to values exceeding the allowable, which intensifies cracking of this rock zone to a greater depth, the deeper the fracturing of the rock beyond the dam. Owing to this, the stress state of the foundation directly under the dam, accompanied by a decrease of the bearing capacity of the rock and increase of its deformation with loss of the required seepage strength, worsens.
- OSTI ID:
- 62926
- Journal Information:
- Hydrotechnical Construction, Vol. 28, Issue 2; Other Information: PBD: Aug 1994; TN: Translated from Gidrotekhnicheskoe Stroitel`stvo; No. 2, 27-34(Feb 1994)
- Country of Publication:
- United States
- Language:
- English
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