Earthquakes and Structures

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Effect of biaxial stress state on seismic fragility of concrete gravity dams

  • Sen, Ufuk (General Directorate of State Hydraulic Works) ;
  • Okeil, Ayman M. (Department of Civil and Environmental Engineering, Louisiana State University)
  • Received : 2019.02.22
  • Accepted : 2019.12.26
  • Published : 2020.03.25
⟨ Previous Next ⟩

Abstract

Dams are important structures for management of water supply for irrigation or drinking, flood control, and electricity generation. In seismic regions, the structural safety of concrete gravity dams is important due to the high potential of life and economic loss if they fail. Therefore, the seismic analysis of existing dams in seismically active regions is crucial for predicting responses of dams to ground motions. In this paper, earthquake response of concrete gravity dams is investigated using the finite element (FE) method. The FE model accounts for dam-water-foundation rock interaction by considering compressible water, flexible foundation effects, and absorptive reservoir bottom materials. Several uncertainties regarding structural attributes of the dam and external actions are considered to obtain the fragility curves of the dam-water-foundation rock system. The structural uncertainties are sampled using the Latin Hypercube Sampling method. The Pine Flat Dam in the Central Valley of Fresno County, California, is selected to demonstrate the methodology for several limit states. The fragility curves for base sliding, and excessive deformation limit states are obtained by performing non-linear time history analyses. Tensile cracking including the complex state of stress that occurs in dams was also considered. Normal, Log-Normal and Weibull distribution types are considered as possible fits for fragility curves. It was found that the effect of the minimum principal stress on tensile strength is insignificant. It is also found that the probability of failure of tensile cracking is higher than that for base sliding of the dam. Furthermore, the loss of reservoir control is unlikely for a moderate earthquake.

Keywords

Acknowledgement

The authors would like to acknowledge the financial support provided to the first author by the General Directorate of State Hydraulic Works, The Republic of Turkey, to pursue his graduate studies in the United States. Additional support from the Department of Civil and Environmental Engineering at Louisiana State University is also acknowledged. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsoring agencies.

References

  1. ACI (2014). "Building Code Requirements for Structural Concrete and Commentary (ACI 318-14)", 317.
  2. ANSYS (2018), Theory Reference Manual, version 18.2, Canonsburg, P.A. U.S.A.
  3. ASCE (2017), "2017 Report Card for America's Infrastucture: Dams", American Society of Civil Engineers.
  4. Bernier, C., Padgett, J.E., Proulx, J., and Paultre, P. (2016), "Seismic fragility of concrete gravity dams with spatial variation of angle of friction: case study", J. Struct. Eng., 142(5), 05015002. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001441.
  5. Chavez, J.W., and Fenves, G.L. (1995). "Earthquake analysis of concrete gravity dams including base sliding", Earthq. Eng. Struct. Dyn., 24(5), 673-686. https://doi.org/10.1002/eqe.4290240505.
  6. Cho, I.H. and Hall, J.F. (2014), "General confinement model based on nonlocal information", J. Eng. Mech., 140(6), 17. https://doi.org/10.1002/eqe.4290240505.
  7. De Araujo, J.M. and Awruch, A.M. (1998), "Probabilistic finite element analysis of concrete gravity dams", Advan. Eng. Soft., 29(2), 97-104. https://doi.org/10.1016/S0965-9978(98)00052-0.
  8. De Biasio, M., Grange, S., Dufour, F., Allain, F. and Petre-Lazar, I. (2015), "Intensity measures for probabilistic assessment of non-structural components acceleration demand", Earthq. Eng. Struct. Dyn., 44(13), 2261-2280. https://doi.org/10.1002/eqe.2582.
  9. Ellingwood, B. and Tekie, P.B. (2001), "Fragility analysis of concrete gravity dams", J. Infr. Sys., 7(2), 41-48. https://doi.org/10.1061/(ASCE)1076-0342(2001)7:2(41).
  10. Fenves, G., and Chopra, A.K. (1984), "Earthquake analysis of concrete gravity dams including reservoir bottom absorption and dam water foundation rock interaction", Earthq. Eng. Struct. Dyn., 12(5), 663-680. https://doi.org/10.1002/eqe.4290120507.
  11. Fenves, G., and Chopra, A.K. (1987), "Simplified earthquake analysis of concrete gravity dams", J. Struct. Eng., 113(8), 1688-1708. https://doi.org/10.1061/(ASCE)0733-9445(1987)113:8(1688).
  12. Ghanaat, Y., Patev, R.C. and Chudgar, A.K. (2012), "Seismic fragility analysis of concrete gravity dams", 15th World Conference on Earthquake Engineering, Sociedade Portuguesa de Engenharia Sismica (SPES), Lisbon, Portugal.
  13. Goldgruber, M., Shahriari, S. and Zenz, G. (2015). "Dynamic sliding analysis of a gravity dam with fluid - structure-foundation interaction using finite elements and newmark's sliding block analysis", Rock Mech. Rock Eng., 48(6), 2405-2419. https://doi.org/10.1007/s00603-015-0714-1.
  14. Haldar, A. and Mahadevan, S. (2000), Probability, reliability and statistical methods in engineering design, John Wiley, New Jersey. U.S.A.
  15. Hariri-Ardebili, M.A., and Saouma, V.E. (2016a), "Collapse fragility curves for concrete dams: comprehensive study", J. Struct. Eng., 142(10), 04016075. https://doi.org/10.1061/(ASCE)ST.1943-541X.0001541.
  16. Hariri-Ardebili, M.A., and Saouma, V.E. (2016b), "Seismic fragility analysis of concrete dams: A state-of-the-art review", Eng. Struct., 128(1), 374-399. https://doi.org/10.1016/j.engstruct.2016.09.034.
  17. Hoek, E. and Brown, E.T. (1997), "Practical estimates of rock mass strength", Int. J. Rock Mech. Min., 34(8), 1165-1186. https://doi.org/10.1016/S1365-1609(97)80069-X.
  18. Kupfer, H.B., Hilsdorf, H.K. and Rusch, H. (1969), "Behavior of concrete under biaxial stresses", ACI J. Proceedings, 6(8), 656-666.
  19. Leger, P. and Boughoufalah, M. (1989), "Earthquake input mechanisms for time-domain analysis of dam-foundation systems", Eng. Struct., 11(1), 37-46. https://doi.org/10.1016/0141-0296(89)90031-X.
  20. Li, L.X. Li, H.N. and Li, C. (2018), "Seismic fragility assessment of self-centering RC frame structures considering maximum and residual deformations", Struct. Eng. Mech., 68(6), 677-689. https://doi.org/10.12989/sem.2018.68.6.677.
  21. Liang, X. and Sritharan, S. (2018), "Effects of confinement in circular hollow concrete columns", J. Struct. Eng., 144(9), 13, 04018159.
  22. Lokke, A., and Chopra, A. K. (2015). "Response Spectrum Analysis of Concrete Gravity Dams Including Dam-Water-Foundation Interaction." J Struct Eng, 141(8), 04014202. https://doi.org/10.1061/(ASCE)ST.1943-541X.0002151.
  23. Lupoi, A. and Callari, C. (2011), "A probabilistic method for the seismic assessment of existing concrete gravity dams", Struct. Infr. Eng., 8(10), 985-998. https://doi.org/10.1080/15732479.2011.574819.
  24. Moradloo, J., Naserasadi, K. and Zamani, H. (2018), "Seismic fragility evaluation of arch concrete dams through nonlinear incremental analysis using smeared crack model", Struct. Eng. Mech., 68(6), 747-760. https://doi.org/10.12989/sem.2018.68.6.747.
  25. Morales-Torres, A., Escuder-Bueno, I., Altarejos-Garcia, L. and Serrano-Lombillo, A. (2016), "Building fragility curves of sliding failure of concrete gravity dams integrating natural and epistemic uncertainties", Eng. Struct., 125(15), 227-235. https://doi.org/10.1016/j.engstruct.2016.07.006.
  26. Nielson, B.G. and DesRoches, R. (2007), "Seismic fragility methodology for highway bridges using a component level approach", Earthq. Eng. Struct. Dyn., 36(6), 823-839. https://doi.org/10.1002/eqe.655.
  27. Nowak, A.S. and Collins, K.R. (2000), Reliability of Structures, McGraw Hill, U.S.A.
  28. Nowak, A.S. and Szerszen, M.M. (2003), "Calibration of design code for buildings (ACI 318): Part 1 - Statistical models for resistance", ACI Struct. J., 100(3), 377-382.
  29. Okeil, A. M. (2006). "Allowable tensile stress for webs of prestressed segmental concrete bridges." ACI Struct J, 103(4), 488-495.
  30. PEER (2018), "PEER Strong Ground Motion Database."Pacific Earthquake Engineering Research Center.
  31. Salimi, M.R. and Yazdani, A. (2018), "Reliability-based fragility analysis of nonlinear structures under the actions of random earthquake loads", Struct. Eng. Mech., 66(1), 75-84. https://doi.org/10.12989/sem.2018.66.1.075.
  32. Sen, U. (2018), "Risk Assessment of Concrete Gravity Dams under Earthquake Loads." M.S. Thesis, Department of Civil and Environmental Engineering, Louisiana State University. Louisiana. U.S.A.
  33. Tekie, B.P., and Ellingwood, B.R. (2003), "Seismic fragility assessment of concrete gravity dams", Earthq. Eng. Struct. Dyn., 32, 2221-2240. https://doi.org/10.1002/eqe.325.
  34. USACE (1995), Gravity Dam Design, US Army Corps of Engineers, Washington, D.C. U.S.A.
  35. USGS (2018), "Unified Hazard Tool", United States Geological Survey, Unified Hazard Tool.
  36. Vu, X.H., Malecot, Y., Daudeville, L. and Buzaud, E. (2009), "Experimental analysis of concrete behavior under high confinement: Effect of the saturation ratio", Int. J. Solids Struct., 46(5), 1105-1120. https://doi.org/10.1016/j.ijsolstr.2008.10.015.