SEISMIC ANALYIS OF CONCRETE ARCH DAMS - TWO CASE STUDIES

SEISMIC ANALYIS OF CONCRETE ARCH DAMS - TWO CASE STUDIES

Azevedo, N. Monteiro; Lemos, J.V.; Matos, D. Silva; Paixão, José

Full Article:

In the framework of the Portuguese National Programme for Dams with High Hy-droelectric Potential (PNBEPH), a set of large concrete dams is currently under design or construction, including several 100 m high arch dams. Earthquake loading is one of the im-portant aspects to be considered in the design of these structures. A variety of numerical methods have been developed over the years by various researchers and are presently availa-ble for seismic analysis of concrete dams. The methods in use by the dam engineering com-munity have different approaches, for example, in the representation of the seismic action, the dam-water interaction or the structural nonlinear behavior. In the paper, the models applied in the study of new Portuguese dams are presented, and their fundamental assumptions dis-cussed. In particular, the analysis of the response of arch dams to the Maximum Design Earthquake is examined, considering the non-elastic behavior of the contraction joints and the dam foundation. An explicit time integration algorithm was used in these simulations, allowing a detailed representation of the slip and separation events along the discontinuities. The boundary conditions appropriate for seismic analysis are discussed, namely the type of free-field boundaries employed. In the paper, the application of this modeling methodology to two new dams is presented and discussed. Foz Tua dam, that is already under construction, is a concrete arch dam, 108 m high and 275 m long at the crest. Fridão dam is also a concrete arch dam, 98 m high and with a crest length of 300 m. Design criteria and the results of the numerical analyses are discussed.

In the framework of the Portuguese National Programme for Dams with High Hy-droelectric Potential (PNBEPH), a set of large concrete dams is currently under design or construction, including several 100 m high arch dams. Earthquake loading is one of the im-portant aspects to be considered in the design of these structures. A variety of numerical methods have been developed over the years by various researchers and are presently availa-ble for seismic analysis of concrete dams. The methods in use by the dam engineering com-munity have different approaches, for example, in the representation of the seismic action, the dam-water interaction or the structural nonlinear behavior. In the paper, the models applied in the study of new Portuguese dams are presented, and their fundamental assumptions dis-cussed. In particular, the analysis of the response of arch dams to the Maximum Design Earthquake is examined, considering the non-elastic behavior of the contraction joints and the dam foundation. An explicit time integration algorithm was used in these simulations, allowing a detailed representation of the slip and separation events along the discontinuities. The boundary conditions appropriate for seismic analysis are discussed, namely the type of free-field boundaries employed. In the paper, the application of this modeling methodology to two new dams is presented and discussed. Foz Tua dam, that is already under construction, is a concrete arch dam, 108 m high and 275 m long at the crest. Fridão dam is also a concrete arch dam, 98 m high and with a crest length of 300 m. Design criteria and the results of the numerical analyses are discussed.

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DOI: 10.5151/meceng-wccm2012-19851

Referências bibliográficas

• [1] Lemos J.V., “Discrete element analysis of dam foundations”, in Distinct Element Modelling in Geomechanics (eds. Sharma, Saxena Andamp; Woods), Balkema, 89-115, 1999.
• [2] Câmara R.C., “A method for coupled arch-dam-foundation-reservoir seismic behaviour analysis”, Earthquake Engineering and Structural Dynamics, 29(4):441-460, 2000.
• [3] EDP, Gestão da Produção de Energia, S. A., Foz Tua Hydroelectric Project - Design, 2010. (in Portuguese)
• [4] EDP, Gestão da Produção de Energia, S. A., Fridão Hydroelectric Project - Design, 2011. (in Portuguese)
• [5] Portuguese Regulations for Safety of Dams, Decreto Lei nº198 de 15 de Outubro, 2007. (in Portuguese)
• [6] Portuguese Dam Design Recommendations (PDDR), Anexo à Portaria nº 846/93, 1993. (in Portuguese)
• [7] ICOLD, Bulletin 72. Selecting Seismic Parameters for Large Dams, 1989.
• [8] LNEC, Foz Tua Hydroelectric Project. Seismic studies. Characterization of the seismic action, Report 205/2010, LNEC, Lisbon, 2010. (in Portuguese)
• [9] LNEC, Fridão Hydroelectric Project. Seismic studies. Characterization of the seismic action, Report 269/2009, LNEC, Lisbon, 2009. (in Portuguese)
• [10] Itasca, 3DEC Three-Dimensional Distinct Element Code, Version 4.0, Itasca Consulting Group, Minneapolis, USA, 2006.
• [11] LNEC, Analysis of the dynamic behaviour of Foz Tua dam for the Maximum Design Earthquake, Report 189/2010, LNEC, Lisbon, 2010. (in Portuguese)
• [12] LNEC, Analysis of the dynamic behaviour of the main dam of Fridão Hydroelectric Project for the Maximum Design Earthquake, Report 140/2011, LNEC, Lisbon, 2011. (in Portuguese)

Como citar:

Azevedo, N. Monteiro; Lemos, J.V.; Matos, D. Silva; Paixão, José; "SEISMIC ANALYIS OF CONCRETE ARCH DAMS - TWO CASE STUDIES", p-4381-4393. In: In Proceedings of the 10th World Congress on Computational Mechanics [= Blucher Mechanical Engineering Proceedings, v. 1, n. 1]. São Paulo: Blucher, 2014.
ISSN 23580828, DOI 10.5151/meceng-wccm2012-19851