2007 – Upgrade of the Aviemore spillway and sluice gates for dam safety operation

Ken Ho, Robert Davey and Jim Walker

The Aviemore Dam appurtenant structures were upgraded for seismic performance in 2006. A comprehensive dam safety review programme conducted by Meridian Energy evaluated the performance of the dam and appurtenant works under extreme ground movements and rupture displacements of the Waitangi Fault, which passes through the embankment dam foundation. The spillway and sluice gates are key elements of the dam safety critical plant for the passage of floods to prevent overtopping or emergency dewatering of the reservoir after a major seismic event if there are concerns about damage to the dam. This paper outlines the assessment undertaken for the spillway and sluice gates for seismic performance and the upgrade necessary to safeguard their integrity for operation after the event.

The spillway and sluice gates are large steel radial gates operated by electrically powered wire rope winches and hydraulic actuation, respectively. Combined hydrostatic and the Safety Evaluation Earthquake (SEE) induced hydrodynamic loads would be expected to stress the gate structures beyond their yield capacity. The yield would be downstream only due to the influence of the hydrostatic load under the earthquake response cycle. The resulting deformations were predicted to fracture connecting bolts in the spillway gate arms and cause severe leakages past the top leaf of the sluice gates. The solutions developed for the spillway gates to reduce connection bolt damage and the strengthening of the sluice gates will ensure their post-earthquake operation.

Keywords: Aviemore Dam, spillway, sluice, radial gate, seismic performance, post-earthquake operation.

Buy this resource