leismic Stability Analyses on Elderberry Forebay Dam

摘要

Elderberry Forebay Dam is a zoned earthfill embankment dam. This paper presents results of seismic stability analyses on the dam using the recently developed design response spectrum. In the analyses, the Bray-Travasarou method was used to estimate earthquake-induced embankment slope displacements. For comparison purpose, earthquake-induced embankment slope displacements were also calculated with the Makdisi-Seed method. To represent the dynamic resistance of the dam, the yield accelerations determined from the pseudo-static analyses were used. The results of the analyses indicate that the dam is expected to deform under the maximum credible earthquake. The estimated earthquake-induced displacement for the most critical full reservoir condition is approximately 13.34 to 49.57 cm (0.44 to 1.63 ft). The sliding displacement may result in minor settlement and cracking of the crest and in surface raveling of the embankment slopes, but are not expected to compromise the integrity of the dam. The displacements are not expected to adversely affect the outlet conduit. The dam is likely to survive the potential earthquakes with only minor damage, and thus does not pose a significant safety hazard.