Natural Hazards and Earth System Science www.nat-hazards-earth-syst-sci.net 1561-8633 1684-9981 8 1 2008 10.5194/nhess-8-9-2008 http://www.nat-hazards-earth-syst-sci.net/8/9/2008/ http://www.nat-hazards-earth-syst-sci.net/8/9/2008/nhess-8-9-2008.html http://www.nat-hazards-earth-syst-sci.net/8/9/2008/nhess-8-9-2008.pdf 9 18 2008-01-10 Performance of heterogeneous earthfill dams under earthquakes: optimal location of the impervious core S. López-Querol mariasusana.lopez@uclm.es P. J. M. Moreta Lecturer, Department of Civil Engineering, University of Castilla La Mancha, Avda. Camilo José Cela s/n, 13071 – Ciudad Real, Spain MSc Civil Engineering, C/ San Gerardo, 6, 28035, Madrid, Spain now at: Academic Visitor, Dept. of Civil and Environmental Eng., Imperial College London, UK Earthfill dams are man-made geostructures which may be especially damaged by seismic loadings, because the soil skeleton they are made of suffers remarkable modifications in its mechanical properties, as well as changes of pore water pressure and flow of this water inside their pores, when subjected to vibrations. The most extreme situation is the dam failure due to soil liquefaction. Coupled finite element numerical codes are a useful tool to assess the safety of these dams. In this paper the application of a fully coupled numerical model, previously developed and validated by the authors, to a set of theoretical cross sections of earthfill dams with impervious core, is presented. All these dams are same height and have the same volume of impervious material at the core. The influence of the core location inside the dam on its response against seismic loading is numerically explored. The dams are designed as strictly stable under static loads. As a result of this research, a design recommendation on the location of the impervious core is obtained for this type of earth dams, on the basis of the criteria of minor liquefaction risk, minor soil degradation during the earthquake and minor crest settlement. Alarcón-Guzmán, A., Leonards, G A., and Chameau, J L.: Undrained monotonic and cyclic strength of sands, J. Geotech. Eng., 114, 1089–1109, 1988. Bardet, J P.: Scaled memory model for cyclic behavior of soils, J. Geotech. Eng., 121, 766–775, 1995. Bardet, J P. and Davis, C A.: Performance of San Fernando Dams during 1994 Northridge earthquake, J. Geotech. Eng., 122, 554–564, 1996. Biot, M A.: Theory of propagation of elastic waves in fluid-saturated porous solid. I, J. Acoust. Soc. Am., 28, 168–178, 1956. Blázquez, R. and López-Querol, S.: Generalized densification law for dry sand due to dynamic loading, Soil Dyn. Earthq. Eng., 26, 888–898, 2006. Blázquez, R. and López-Querol, S.: Endochronic-based approach to the failure of the Lower San Fernando Dam in 1971, J. Geotech. Geoenviron., 133, 1144–1153, 2007. Blázquez, R., Krizek, R J., and Ba\vzant, Z P.: Site factors controlling liquefaction, J. Geotech. Eng.-Asce, 106, 785–801, 1980. Byrne, P M.: Earthquake induced damage mitigation from soil liquefaction, available at:http://www.civil.ubc.ca/liquefaction/, 2005. Dafalias, Y F. and Popov, E P.: Plastic internal variable formalism of cyclic plasticity, J. Appl. Mech., 98, 645–650, 1976. Davis, C A. and Bardet, J P.: Performance of two reservoirs during 1994 \textscNorthridge earthquake, J. Geotech. Eng., 122, 613–622, 1996. Finn, W. D L. and Khanna, J.: Dynamic response of earth dams, in: Third Symposium on Earthquake Engineering, Sah Cement Company, New Delhi (India), 1966. Gajo, A. and Wood, D M.: A kinematic hardening constitutive model for sands: the multiaxial formulation, Int. J. Numer. Anal. Met., 23, 925–965, 1999. Ishihara, K., Tatsuoka, F., and Yasuda, S.: Undrained deformation and liquefaction of sand under cyclic stresses, Soils Found., 15, 29–44, 1975. López~Querol, S.: Modelización geomecánica de los procesos de densificación, licuefacción y movilidad c\'iclica de suelos granulares sometidos a solicitaciones dinámicas , E T S Ingenieros de Caminos, Canales y Puertos, Universidad de Castilla-La Mancha, Ciudad Real (Spain), Ph.D. thesis, 2005 in Spanish. López-Querol, S. and Blázquez, R.: Liquefaction and cyclic mobility model for saturated granular media, Int. J. Numer. Anal. Met., 30, 413–439, 2006. López-Querol, S. and Blázquez, R.: Validation of a new endochronic liquefaction model for granular soil by using centrifuge test data, Soil Dyn. Earthq. Eng., 27, 920–937, 2007. Manzari, M T. and Dafalias, Y F.: A critical state two-surface plasticity model for sands, Geotechnique, 47, 255–272, 1997. Martin, G R., Finn, W. D L., and Seed, H B.: Fundamentals of Liquefaction under Cyclic Loading, J. Geotech. Eng., 101, 423–438, 1975. Mejia, L H., Sun, J I., and Leung, K K.: Seismic upgrade of hydraulic fill dam buttressing, Soil Dyn. Earthq. Eng., 25, 571–579, 2005. Ming, H Y. and Li, X S.: Fully coupled analysis of failure and remediation of Lower San Fernando Dam, J. Geotech. Geoenviron., 129, 336–349, 2003. Mira, P., Pastor, M., Li, T., and Liu, X.: A new stabilized enhanced strain element with equal order of interpolation for soil consolidation problems, Comput. Method. Appl. M., 192, 4257–4277, 2003. Olson, S.: Liquefaction analysis of level and sloping ground using field case histories and penetration resistance, Ph.D. thesis, University of Illinois at Urbana-Champaign, Urbana, Illinois, (available at:http://pgi-tp.ce.uiuc.edu/olsonwebfiles/olsonweb/index.htm), 2001. Olson, S M. and Stark, T D.: Liquefied strength ratio from liquefaction flow case histories, Can. Geotech. J., 39, 329–347, 2002. Papadimitriou, A G., Bouckovalas, G D., and Dafalias, Y F.: Plasticity model for sand under small and large cyclic strains, J. Geotech. Geoenviron., 127, 973–983, 2001. Pastor, M., Zienkiewicz, O., and Chan, A.: Generalized plasticity and the modelling of soil behaviour, Int. J. Numer. Anal. Met., 14, 151–190, 1990. Prevost, J H.: A simple plasticity theory for frictional cohesionless soils, Soil Dyn. Earthq. Eng., 4, 9–17, 1985. Seed, H B.: 19TH Rankine Lecture – Considerations in the earthquake resistant design of earth and rock fill dams, Géotechnique, 98, 213–263, 1979. Seed, H B., Lee, K L., Idriss, I M., and Makdisi, F I.: Analysis of the slides in the San Fernando Dams during the earthquake on 9 February 1971, Tech. Rep. EERC 73-2, Earthquake Engineering Research Center, University of California, Berkeley, CA, 1973. Seed, H B., Seed, R B., Harder, L F., and Jong, H L.: Re-evaluation for the lower San Fernando dam, Report 2, Examination of the post-earthquake slide of 9 February 1971, H Bolton Seed, Inc., Department of the Army, US Army Corps of Engineers, 1989. Sherard, J L.: Earthquake considerations in earth dam design, J. Soil Mech. Found. Div. – ASCE, 93, 377–401, 1967. Vallarino, E.: Tratado básico de presas, Colegio de Ingenieros de Caminos, Canales y Puertos, Colección Seinor, 2001 in Spanish. Wieland, M. and Malla, S.: Seismic safety evaluation of a 117 m high embankment dam resting on a thick soil layer, Paper 128, in: 12th European Conference on Earthquake Engineering, edited by Ltd., E S., 2002. Wijewickreme, D., Sriskandakumar, S., and Byrne, P.: Cyclic loading response of loose air-pluviated Fraser River sand for validation of numerical models simulating centrifuge tests, Can. Geotech. J., 42, 550–561, 2005. Wu, G.: Earthquake-induced deformation analyses of the Upper San Fernando Dam under the 1971 San Fernando Earthquake, Can. Geotech. J., 38, 1–15, 2001. Wylie, E B., Streeter, V L., Papadakis, C N., and Richart~Jr., F E.: Earthquake resistance of earth and rock-fill dams. Repor 4: Transient two-dimensional analysis of soils by Latticework method, Lopez dam case study, Tech. rep., Department of Civil Engineering. The University of Michigan, Ann Arbor, Mich., 48104, 1975. Zienkiewicz, O C. and Xie, Y M.: Analysis of Lower San Fernando dam failure under earthquake, Dam Engineering, 2, 307–322, 1991. Zienkiewicz, O C., Chang, C T., and Bettes, P.: Drained, undrained, consolidating and dynamic behaviour assumptions in soils, Géotechnique, 30, 385–395, 1980. Zienkiewicz, O C., Chan, A. H C., Pastor, M., Scherefler, B A., and Shiomi, T.: Computational Geomechanics with Special Reference to Earthquake Engineering, John Wiley & Sons Ltd, Chichester, England, 1999.