Scrivener Dam physical model
Scrivener Dam is a critical piece of Canberra’s infrastructure, maintaining water levels of the iconic Lake Burley Griffin. Like all dams in Australia, it requires regular maintenance and assessment to ensure ongoing safe operation. A recent inspection identified potential for undesirable uplift forces under the stilling basin slab, triggering a more detailed assessment of dam stability.
UNSW Sydney’s Water Research Laboratory was commissioned by the National Capital Authority to construct and test a 1:40 scale physical model of the dam in WRL’s hydraulics laboratory at Manly Vale.
Despite advances in numerical (computer) modelling, physical modelling remains the most trusted method for determining complex hydraulic behaviours found in dams, particularly in the energy dissipation basins. Modelling provides critical data on flow behaviours, pressures and forces that impact the dam structure, and allows engineers to design the structure appropriately.
Dam models generally need to be constructed at large scales to minimise scale effects. WRL’s purpose built hydraulic facilities were ideal for the model which measured 25 x 9 m. Large pumps precisely delivered over 1,000 L/s to the model. While the model is large, it also needed to be constructed to a high level of accuracy, with WRL’s specialist engineers and craftsmen ensuring an accuracy of <1 mm across the dam structure.
The results of the physical model testing will be used to form part of the overall risk assessment for the dam; ensuring the ongoing safe operation of Scrivener Dam into the future.