Andrew Pattle and Bram Knoop
This paper provides an outline of a process that can be used to optimise regular dam surveillance and monitoring activities. The process is applicable for a wide range of dam types that an owner/operator may be responsible for. Basic assessments are made of inherent reliability and potential consequences of failure using key factors such as construction features, foundation conditions and observed performance. The key factors are combined to give a relative risk ranking for each dam. These rankings are used to determine specific dam monitoring schedules. The process focuses the monitoring effort on those dams that are perceived to constitute the greatest portion of the overall risk. The methodology is simple and provides a cost-effective framework for setting appropriate resourcing levels for dam monitoring.
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Now showing 1-12 of 31 2948:
M Scuero and Gabriella L Vaschetti
The use of watertight synthetic geomembranes as waterproofing and protection elements for all types of dams started in Europe in the late 1950s and has since been widely applied all over the world as long term repair measure, or as the only element providing watertightness since the design and construction stage.
I A Howley, G S Smith and D J A Stewart
Over the past decade the role of dam ownership in Victoria, and indeed Australia, has changed from one of owners, constructors and operators of large civil assets, to managers of structures on behalf of owners of the entitlements to water. This is part of the key business focus to dams management in Victoria.
This position has been heavily influenced by regional water reform policies, such as the Murray Darling Cap, and its effects in Northern Victoria, and COAG Agreements.
Dam owners now run service driven businesses, with a clear separation of roles and responsibilities from the traditional, engineering focused organisations which were established in an environment of resource development. The environment is now one of maintenance, service delivery, structure maintenance and long term business viability for ultimate community benefit.
By using Goulburn-Murray Water as an example, the current model of dams management in Victoria is outlined, together with possible future directions for the rural water industry in Victoria.
Gary Gibson, Wayne Peck, Ian Landon-Jones and Kumara Arachchi
One of the first seismograph networks designed specifically to record local earthquakes was installed about Sydney in 1958. This network was converted to telemetry in 1983. In 1992, Sydney Water Corporation upgraded the network, integrating the functions of earthquake location and magnitude, measurement of the response of structures to earthquake motion, and provision of information for emergency response. The response function has been developed over the past six years, and is now an “Earthquake Preparation, Alarm and Response” system that provides customised information very soon after any significant event.
Leonard A McDonald and Chi Fai Wan
A risk assessment has been undertaken as part of a comprehensive review of the safety of Hume Dam. Use of risk assessment techniques, to assist in evaluating the safety of existing dams, is a relatively recent trend. Hume Dam was a particularly challenging subject for the application of risk assessment techniques at their present stage of development. The challenge lay in the number and diversity of dam elements to be analysed, in the number and complexity of the potential failure modes and in the fact that there were significant safety issues under normal operating conditions.
This paper outlines some of the key lessons learned from that phase of the risk assessment that was concerned with estimating the chance of dam failure. Some of the issues discussed have not previously been addressed in the literature and some demonstrate a clear need for improved analysis procedures.
Richard I Herweynen
For concrete gravity dams, when the foundation’s value of cohesion is low, it is very difficult to meet the sliding criteria proposed by ANCOLD. Low cohesion is generally associated with serious foundation defects. This was the case for Meadowbank Dam, with a foundation having persistent horizontal seams containing material of a clayey silt size classification. By adopting the ANCOLD strength reduction factors, it was found that a large number of ground anchors would be required to meet the ANCOLD sliding criteria. During original design, extensive laboratory and insitu testing was performed on the seam material. This paper proposes a methodology for arriving at less severe strength reduction factors based upon a statistical analysis of the strength parameters measured in the Meadowbank Dam foundation.
Additionally, a probabilistic approach using a Monte Carlo simulation is used to give further weight to this argument. This paper concludes that the probability of Meadowbank Dam failing due to sliding is very low and within acceptable limits.