Abstract
Earth dams are massive water-retaining structures that are used widely in the world for irrigation, water supply and hydroelectric energy generation. Many such dams are built every year and the International Committee on Large Dams (ICOLD) has gathered together experts from the world to work on preparing guidelines for design, construction and monitoring of such massive infrastructure. A potential failure of a large dam may potentially have significant effects on a huge area downstream, as the sudden release of the large volume of retained water can travel for large distances and destroy entire cities and even result in unfortunate fatalities.
It is therefore important to recognise the potential causes of failure of such dams and provide timely and effective measures to prevent any degradation or loss of stability. The main threats for dams are seismic activity, internal erosion, faulting and seasonal climate variations. The latter factor, i.e. climate changes, has not been studied widely and therefore there is a need for further understanding of the problem. In arid and tropical climates, e.g. the Mediterranean, Middle East, south Asia, large changes in the temperature and rainfall cause significant variations in the upstream reservoir level. This results in the dam rockfill undergoing cycles of wetting and drying which further causes permanent displacements and potentially cracking. Such structural response needs to be closely monitored, so that any potential leakage (and therefore erosion) is prevented.
This keynote paper presents an experimental study to investigate the effects of seasonal climate variations on the deformations of earth dams. A well-instrumented dam in Cyprus, the Kouris earth dam, which is the largest dam in the country is used as a case study. Long-term monitoring data from three-independent and different instrumentation sets are collected, processed and analysed. A periodic variation in the crest settlements is identified and thus relevant statistical analysis is performed to identify the dominant frequencies of fluctuations and to examine any relation between the dam crest settlements and the reservoir level changes. Subsequently, a nonlinear coupled hydro-mechanical finite element analysis is performed which models the entire stress history of the dam, i.e. layered construction, reservoir impoundment, consolidation and reservoir level changes. The latter finite element analysis attempts to identify the relative effects of soil consolidation and reservoir level changes on the induced dam displacements.
It is therefore important to recognise the potential causes of failure of such dams and provide timely and effective measures to prevent any degradation or loss of stability. The main threats for dams are seismic activity, internal erosion, faulting and seasonal climate variations. The latter factor, i.e. climate changes, has not been studied widely and therefore there is a need for further understanding of the problem. In arid and tropical climates, e.g. the Mediterranean, Middle East, south Asia, large changes in the temperature and rainfall cause significant variations in the upstream reservoir level. This results in the dam rockfill undergoing cycles of wetting and drying which further causes permanent displacements and potentially cracking. Such structural response needs to be closely monitored, so that any potential leakage (and therefore erosion) is prevented.
This keynote paper presents an experimental study to investigate the effects of seasonal climate variations on the deformations of earth dams. A well-instrumented dam in Cyprus, the Kouris earth dam, which is the largest dam in the country is used as a case study. Long-term monitoring data from three-independent and different instrumentation sets are collected, processed and analysed. A periodic variation in the crest settlements is identified and thus relevant statistical analysis is performed to identify the dominant frequencies of fluctuations and to examine any relation between the dam crest settlements and the reservoir level changes. Subsequently, a nonlinear coupled hydro-mechanical finite element analysis is performed which models the entire stress history of the dam, i.e. layered construction, reservoir impoundment, consolidation and reservoir level changes. The latter finite element analysis attempts to identify the relative effects of soil consolidation and reservoir level changes on the induced dam displacements.
Original language | English |
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Pages | 1-6 |
Publication status | Published - 6 Dec 2017 |
Event | 8th International Conference on Structural Engineering and Construction Management 2017 - Kandy, Sri Lanka Duration: 7 Dec 2017 → 10 Dec 2017 http://www.icsecm.org/2017/ |
Conference
Conference | 8th International Conference on Structural Engineering and Construction Management 2017 |
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Abbreviated title | ICSECM 2017 |
Country/Territory | Sri Lanka |
City | Kandy |
Period | 7/12/17 → 10/12/17 |
Internet address |