Retarding Basin Fundamentals (April 2013) – MODULE 1 TO 4
Retarding basins are becoming increasingly important elements in urban flood planning throughout Australia but it is evident that many basins have not been implemented in line with modern day “risk management” approaches. Accordingly, as part of its Professional Development program, and in advance of its proposed Guideline on Retarding Basins due out in 2014, the Australian National Committee on Large Dams (ANCOLD) is planning a series of seminars across Australia on Retarding Basin Fundamentals. The seminars are being provided to assist basin owners, and their professional staff and advisors, to plan, implement and operate their basins in a safe and effective manner consistent with various Government and “duty of care” obligations.
The one day seminars are being presented by leading dam safety and risk management professionals including:
Richard Rodd- dams consultant with over 40 years experience in dam and basin design, construction, operation and maintenance.
Kelly Maslin – dams consultant with over 15 years experience in dams and risk management.
Norm Himsley – dams consultant and member of NSW Dam Safety Committee with over 40 years experience in dam and basin design, construction, operation and maintenance.
Includes access to the following videos:
$60.00 - $80.00
David Guest, George Samios, Richard Rodd
Tenterfield Creek Dam is a 15m high concrete gravity structure that was constructed in 1930 and raised by 1.83m and stabilised using 97 post-tensioned ground anchors in 1974.Recent stability assessments concluded that the dam does not satisfy the ANCOLD Guidelines for Stability of Gravity Dams and that the situation is likely to deteriorate given the questionable performance of the post-tensioning cables and on the grounds of continuing corrosion and demonstrated loss of load.Tenterfield Shire Council is committed to improving the stability of the dam to meet the requirements of the NSW Dam sSafety Committee and engaged Public Works Advisory to assist them achieve this outcome.
Public Works Advisory prepared a dam upgrade options study which selected two options for further consideration. The estimated costs of the two preferred options were found to be potentially close;therefore Tenterfield Shire Council requested that both options be taken to detail design and tender stage to allow the market to indicate which option was in-fact better value.Factors other than construction costs were also considered in the options evaluation process and these factors influenced the selection outcome. The two upgrade options of lowest cost were the conventional gravity dam strengthen solutions i.e. installation of new post-tensioned ground anchors and downstream mass concrete buttressing. The decision to proceed to tender with two options was supported by the other key funding stakeholder, DPI Water.
This paper provides some unique insight on the comparison of conventional upgrade options for concrete gravity dams and also examines some interesting design aspects encounter edduring the design development process
Ben Ross, Jason Brown, Richard Rodd
Goulburn Weir was constructed in 1891 forming Lake Nagambie on the Goulburn River, approximately 8km north of Nagambie in Victoria. It is a key asset in the irrigation network diverting water to 352,000ha in Northern Victoria. The weir was remodelled between 1983 and 1987, replacing 21 overshot gates with nine radial gates. A series of 28 post tensioned bar ground anchors were installed to secure the radial gate concrete support piers to the weir’s mudstone foundations. On 8 March 2006 during routine testing of the pier bar ground anchors, failure of one anchor occurred. It posed a possible risk to pier stability. Subsequently investigations into the cause of failure and its implications was undertaken consisting of a program of data review, site investigations, metallurgical testing, geotechnical investigation, design reviews and stability assessments. It was recommended to replace the failed anchor and 10 other under performing anchors with 8 cable strand anchors at the cost of approximately $1million.
Key words: Risk, bar anchor failure, stability assessment, anchor construction.
Dam Types, Foundation & Construction (November 2014) – MODULES 1 to 5 (Full Seminar)
COURSE OBJECTIVES AND OUTLINE
This short course is designed to provide sound basic understanding into dam types, foundations and construction, their key issues and considerations including investigations and design and addressing new and existing dams and associated upgrades.
It will begin with looking at all the various types of embankment and concrete dams, their issues and considerations as a lead into choosing or reviewing dam type and associated upgrade including risk assessment, historical performance and basic monitoring for dam safety.
Next foundations types and associated investigations, design and construction key aspects will be covered in view of the importance of this component for both new and existing dams.
To round off basic dam understanding the final sessions will concentrate on preliminary and common construction considerations and in particular construction of embankment and concrete dam walls.
Technical Seminar: Safety Evaluation of Existing Dams Day 3 – MODULE 1- 4
This seminar emphasizes the importance of periodic evaluation of the safety of existing dams, and provides specific information and guidance on the visual and instrumented monitoring of the various types of dams and their appurtenant structures. Failure modes analysis is stressed as the basis for an effective and efficient monitoring program. At the conclusion of the course, attendees will have a thorough understanding of the procedures and techniques essential to carrying out meaningful dam safety evaluations and monitoring, and should be able to apply these principles to improve their own effectiveness and the effectiveness of their dam safety programs.
Hydrometeorology and Hydrology (September 2013) – MODULES 1 TO 5
Guidance for design flood estimation is provided in Australian Rainfall and Runoff. Since the last edition in 1987 there has been development and increasing application of stochastic simulation approaches for design flood estimation. There has been associated improved information and more sophisticated treatment of inputs such as design rainfalls, areal reduction factors, losses, baseflow and initial contents of reservoirs. A significant development has been the recent release of the new IFD estimates from the Bureau of Meteorology. The session will cover improved approaches to design flood estimation such as Mont-Carlo analysis and the characterisation of inputs.