We can all learn by our mistakes and the experience of others. This paper seeks to look at three
incidents/accidents which recently occurred in the UK so that others can learn from them. The
paper then seeks to answer the question as to whether we are improving in looking after our dams
in the UK in respect of reservoir safety.
Now showing 1-12 of 59 2970:
As one of Australia’s largest dam owners, Hydro Tasmania maintains a comprehensive Dam Safety Program. The Program makes use of industry Guidelines in combination with complementary processes to form a decision framework. This framework drives dam improvement initiatives, one of which is the development and operation of survey and instrumentation programs. It is Hydro Tasmania’s belief that the ANCOLD Guidelines on Dam Safety Management currently provide adequate descriptive guidance with regards to survey and instrumentation and it is questionable if more prescriptive Guidelines are prudent or required. Hydro Tasmania believes that a Guideline presenting a decision framework from which targeted Survey, instrumentation and inspection programs and other initiatives can evolve would be a welcomed document to the Australian dams community.
R. Dawson, J. Grimston, R. Cole, D. Bouma
The authors have been involved in the design and construction of several embankment dams in New Zealand over the past decade, and have considerable corporate knowledge from dams designed by the company in its 47-year history. This paper examines four dams which are relatively small to medium, ranging in height from 10 to 19 m with moderate storage volumes. Three of the dams service landfills and the fourth a wood processing mill. Such dams may provide the designer with considerable challenges due to their relatively low capital cost resulting in limited investment in geotechnical investigation at the front end of the project, with varying levels of change often required during construction due to unforeseen conditions as a result of the limited investigations.
The general arrangement and conceptual design principles for each of the dams is described followed by the field investigation and laboratory testing undertaken for each dam, together with the interpreted ground conditions.
The experiences from construction have helped to develop techniques for a balance between preliminary design, investigation, and evolution of the design and specification during construction. It is imperative to develop a sufficiently detailed preliminary design, on the basis of readily available information such as visual and geological assessment, to allow the investigation to be thoughtfully designed to allow the major assumptions to be verified. This needs to be followed by a skilfully executed geotechnical investigation with the designer advising on findings and changing direction as necessary through the investigation. An investigation trench along the full alignment of the cutoff trench (if envisaged in the design) is warranted. Earthworks specifications should be evolved early in the construction phase through compaction trials using specific plant for the site, and backed up by insitu and laboratory testing.
Ridges Basin Dam is part of the Animas-La Plata Project. When topped out in approximately 2008, it will be Reclamation’s newest dam. It will have a structural height of 273 feet and impound 120,000 acre-feet of water. This paper will discuss the design of the embankment and will detail the site geology, the general design considerations for layout and zoning, and other technical considerations. The construction, which began in 2004, is ongoing. This paper will also discuss foundation treatment and cleanup, the placement of the embankment material, grouting, and the unusual material processing for filters and drains, along with general construction details. Also included in the paper are the challenging arrangements for contracting by the American Indian Self Determination and Education Assistance Law, an overview of the dam safety risk analyses conducted on the yet-to-be-constructed embankment, and modern construction techniques being utilized to build the embankment.
Lawrie Schmitt and Angus Paton
As the owner of most of the large dams in South Australia the South Australian Water Corporation (SA Water) is responsible for the safety of these structures and their designed function of water supply and flood control. In order to meet these responsibilities SA Water monitors the performance of the structures using engineering deformation surveys and various forms of instrumentation. This paper outlines the instrumentation and survey monitoring undertaken at SA Water large dams and discusses the issues arising.
Ensuring compliance with the Regulator’s requirements is a cornerstone consideration for any water corporation in planning its risk minimisation strategies against dam failure. With the increased focus on due diligence and corporate governance however, there are emerging themes that are of equal importance for a water corporation in planning protections against its core risks to dam safety.
These considerations include: