A good report for research?10 August 1998
A I B Moffat* considers the best way of ensuring that research is of maximum usefulness
The purist defines research as being systematic investigation designed to add to the span of human knowledge. Viewed in such direct terms research can fairly be justified as an end in itself. To the pragmatist, on the other hand, the measure of the value of research may depend on its impact on society, and the engineering profession is by its nature strongly sympathetic to this viewpoint. To many dam engineers the value of research will be measured through its influence on designer confidence.
Most construction-related research falls into the ‘applied’ category, and only part of it — although embracing disparate sub-disciplines ranging from engineering geology to hydrology — is of immediate interest to the dam engineer.
In addition, much published research in the subject could be viewed as ad hoc problem-solving rather than true research. In some instances this might be fair comment, but it should not be allowed to demean the importance of the work.
As far as dam engineering is concerned the results of quality research — fundamental or applied — all too frequently fail to be assimilated into practice as widely or as rapidly as is desirable.
It can be argued that a reappraisal is required of how research relating to dams is best commissioned and developed. Underpinning such reappraisal, four major points must be considered:
•A limited core of dam-related research can be considered to be universal in its importance. A major proportion of the research will, in contrast, be of immediate relevance at the national (or regional) level.
•Research funding available to the dam engineer will always be modest by comparison with that available in other fields, such as environmental engineering and water resource development. There are few votes to be won from the vigorous promotion of extensive research programmes in dam engineering. This stands in stark contrast with political gains from responding to the demands of vociferous lobby groups for more and more research on high profile issues of the day.
•Much research in dam engineering will continue to be of a highly project-specific nature. The ad hoc nature of applied research is inescapable in the context of dam design and construction. Dams are arguably the most individualistic and unique of heavy structures, but research can nevertheless have a more general and far-reaching impact.
Reviewed on the basis of general applicability and global impact, the most significant research-led developments in dam engineering over recent decades must include:
•The evolution of the roller compacted concrete dam in its several variants.
•The contribution of finite element methods to the rational analysis of dams and to our understanding of dam behaviour.
•The development of graded, compacted rockfill.
•An enhanced understanding of flood hydrology leading to more rational procedures for design flood estimation.
•An improved understanding of the nature and behaviour of compacted earthfill in dams (including hydraulic fracture and the erosion characteristics of fill).
•The development and utilisation of advanced ground engineering and grouting procedures.
•Improved understanding of seismicity and of the seismic response of dams.
•Enhanced monitoring and surveillance capability achieved through the ready availability of reliable instrumentation, together with the development of associated assessment procedures.
The importance of reports
The considerations which drive the identification of research priorities can be illustrated through a brief review of the UK, where the research programme conducted over recent years has proved most productive in a national context. The UK has distinctive features which have had an immediate bearing upon the selection of research priorities:
•A population of some 2500 reservoirs is subject to statutory legislation covering safety (The Reservoir Act (1975): this embraces the design, construction and inspection of dams and applies to all raised reservoirs with a storage capacity in excess of 25,000m3).
•Some 85% of dams are earthfill embankments, of homogeneous or central slim clay core cross-section (cohesive soils suitable for embankments predominate over much of the UK land surface).
•Median age is of the order of 100-110 years, with all that it implies in relation to the original design and construction standards.
•The UK has had a relatively satisfactory record in relation to the safety of dams; no fatalities have resulted from dam failure since 1925.
•There is no auth-oritative and detailed central register of dams; operation and enforce-ment of legislation is delegated.
•UK safety legislation vests responsibility for safety in the appro-priate individual engineer (the ‘Panel Engineer’) to a quite unique degree.
What should be the way ahead?
The writer would suggest the following:
•The national committees of the International Committee on Large Dams (icold) should adopt a more strongly pro-active approach to co-ordinating national research activity.
•There is a place for greater encouragement of co-operative research at a regional level, through selected national groupings (the effective work of the several European Working
Groups operating under the national committees).
•ICOLD’s central co-ordinating function should be predominantly one of formulating strategic aims and objectives.
•The resources devoted to timely dissemination of the results of research, whether strategic or project-specific, should be commensurate with the considerable effort put into such research.
•Dissemination of research and ‘best practice’ guidance is truly effective only when reports are of high quality, are readily accessed, are well publicised and are easy to use (ICOLD Bulletins).
The timely dissemination of research-led understanding is the key to progress in our profession as dam engineers.
It is also fundamental to our ability to develop the increasingly difficult and complex dam sites, to which we are now compelled to turn in many countries, safely and at an acceptable cost.