Investigation on the Effects of Different Incident Angle of Sarpol-e Zahab Earthquake Ground Motions on an Embankment Dam

Document Type : Geotechnical Earthquake Engineering


International Institute of Earthquake Engineering and Seismology


One of the most important challenges in analysis of non-ordinary structures is the critical angle of incidence of earthquake ground motions. To accommodate these directional effects, several procedures and combination rules have been proposed. The major limitations of these methods are that they are restricted to elastic analyses, rarely considered near-fault earthquakes and are almost related to the building structures or bridges. The main objective of this work is to assess the influence of incident angle of ground motions on several engineering demand parameters (EDPs) of an embankment dam under Sarpol-e Zahab earthquake. To achieve this goal, after selecting proper ground motions, the as-recorded horizontal components (two orthogonal) were rotated to: fault-normal/parallel direction, principal direction, direction related to GMrotIpp (NGA relationships) and maximum direction of response history analysis of two degree of freedom system (MSD). In the next step, a typical embankment dam in the earthquakeaffected areas was modeled using the shear beam method. The model was excited by as-recorded motions with various directions in the range of 0-360 degrees with a step of 10 degrees and all four above-mentioned reference axes directions. Numerous equivalent linear analyses were carried out to obtain the critical angles of excitation that leads to maximum responses. The analyses results showed that the critical orientations of ground motions depend on: input motions, structure characteristics and EDPs.


Newmark, N.M. (1975) Seismic design criteria for structures and facilities, Trans-Alaska pipeline system. Proceedings of the US National Conference on Earthquake Engineering.
Rosenblueth, E. and Contreras, H. (1977) Approximate design for multicomponent earthquakes. Journal of the Engineering Mechanics Division, 103(5), 881-893.
Wilson, E.L., Suharwardy, I., and Habibullah, A. (1995) A clarification of the orthogonal effects in a three-dimensional seismic analysis. Earthquake Spectra , 11(4), 659-666.
Menun, C. and Kiureghian, A.D. (1998) A replacement for the 30%, 40%, and SRSS rules for multicomponent seismic analysis. Earthquake Spectra, 14(1), 153-163.
Lopez, O.A., Chopra, A.K., and Hernandez, J.J. (2001) Evaluation of combination rules for maximum response calculation in multicomponent seismic analysis. Earthquake Engineering & Structural Dynamics, 30(9), 1379-1398.
Marinilli, A. and Lopez, O.A. (2008) Evaluation of critical responses and critical incidence angles obtained with RSA and RHA. The 14th World Conference on Earthquake Engineering, Beijing, China.
Athanatopoulou, A. (2005) Critical orientation of three correlated seismic components. Engineering Structures, 27(2), 301-312.
Rigato, A.B. and Medina, R.A. (2007) Influence of angle of incidence on seismic demands for inelastic single-storey structures subjected to bi-directional ground motions. Engineering Structures, 29(10), 2593-2601.
Hariri-Ardebili, M. and Saouma, V. (2014) Impact of near-fault vs. far-field ground motions on the seismic response of an arch dam with respect to foundation type. Dam Eng., 24(1), 19-52.
Fontara, I.K.M., Kostinakis, K.G., Manoukas, G.E., and Athanatopoulou, A.M. (2015) Parameters affecting the seismic response of buildings under bi-directional excitation. Struct. Eng. Mech., 53(5), 957-979.
Mitropoulou, C.C. and Lagaros, N. (2016) Critical incident angle for the minimum cost design of low, mid and high-rise steel and reinforced concrete-composite buildings. Int. J. Optim. Civil Eng., 6(1), 135-158.
Kostinakis, K.G., Manoukas, G.E., and Athanatopoulou, A.M. (2017) Influence of seismic incident angle on response of symmetric in plan buildings. KSCE Journal of Civil Engineering, 1-11.
Roy, A., Santra, A., and Roy, R. (2018) Estimating seismic response under bi-directional shaking per uni-directional analysis: Identification of preferred angle of incidence. Soil Dynamics and Earthquake Engineering, 106, 163-181.
Bozorgnia, Y., Abrahamson, N.A., Atik, L.A., Ancheta, T.D., Atkinson, G.M., Baker, J.W., ... and Darragh, R. (2014) NGA-West2 research project. Earthquake Spectra , 30(3), 973-987.
ASCE/SEI (2016) Minimum Design Loads for Buildings and other Structures. ASCE/SEI 7-16, Reston, VA. 16. Penzien, J. and Watabe, M. (1974) Characteristics of 3-dimensional earthquake ground motions.
Earthquake Engineering and Structural Dynamics, 3(4), 365-373.
Kubo, T. and Penzien, J. (1979) Analysis of three-dimensional strong ground motions along principal axes, San Fernando earthquake. Earthquake Engineering and Structural Dynamics, 7(3), 265-278.
Kubo, T. and Penzien, J. (1979) Simulation of three-dimensional strong ground motions along principal axes, San Fernando earthquake. Earthquake Engineering and Structural Dynamics, 7(3), 279-294.
Reyes, J. and Kalkan, E. (2012) Relevance of fault-normal/parallel and maximum direction rotated ground motions on nonlinear behavior of multi-story buildings. Proceedings of the 15th World Conference on Earthquake Engineering.
Stewart, J.P., Chiou, S.J., Bray, J.D., Graves, R.W., Somerville, P.G., and Abrahamson, N.A. (2002) Ground Motion Evaluation Procedures for Performance-Based Design, in PEER Report 2001/09. University of California, Berkeley: Pacific Earthquake Engineering Research Center.
Mavroeidis, G.P. and Papageorgiou, A.S. (2003) A mathematical representation of near-fault ground motions. Bulletin of the Seismological Society of America , 93(3), 1099-1131.
Maniatakis, C.A., Taflampas, I., and Spyrakos, C. (2008) Identification of near-fault earthquake record characteristics. The 14th World Conference on Earthquake Engineering, Beijing, China.
Somerville, P.G. (2005) Engineering characterization of near fault ground motions. Proc., NZSEE 2005 Conference.
Somerville, P. and Graves, R. (1993) Conditions that give rise to unusually large long period ground motions. The Structural Design of Tall Buildings, 2(3), 211-232.
Somerville, P.G. (2002) Characterizing near fault ground motion for the design and evaluation of bridges. Third National Conference and Workshop on Bridges and Highways, Portland, Oregon.
Bray, J.D. and Rodriguez-Marek, A. (2004) Characterization of forward-directivity ground motions in the near-fault region. Soil Dynamics and Earthquake Engineering, 24(11), 815-828.
Lu, Y. and Panagiotou, M. (2014) Characterization and Representation of Pulse-like Ground Motions Using Wavelet-Based Cumulative Pulse Extraction.
Kalkan, E. and Kwong, N.S. (2013) Pros and cons of rotating ground motion records to fault normal/ parallel directions for response history analysis of buildings. Journal of Structural Engineering, 140(3), 04013062.
Davoodi, M., Jafari, M.K., and Hadiani, N. (2013) Seismic response of embankment dams under near-fault and far-field ground motion excitation. Engineering Geology, 158, 66-76.
Hadiani, N., Davoodi, M., and Jafari, M. (2013) Correlation between settlement of embankment dams and ground motion intensity indices of pulse-like records. Iranian Journal of Science and Technology. Transactions of Civil Engineering, 37(C1), 111.
Boore, D.M., Watson-Lamprey, J., and Abrahamson, N.A. (2006). Orientation-independent measures of ground motion. Bulletin of the seismological Society of America, 96(4A), 1502-1511.
Baker, J.W., and Cornell, C.A. (2006). Which spectral acceleration are you using? Earthquake Spectra , 22(2), 293-312.
Huang, Y.-N., Whittaker, A.S., and Luco, N. (2008) Maximum spectral demands in the near-fault region. Earthquake Spectra , 24(1), 319-341.
Huang, Y.-N., Whittaker, A.S., and Luco, N. (2009) Orientation of maximum spectral demand in the near-fault region. Earthquake Spectra, 25(3), 707-717.
IIEES (2017) Preliminary Report of Mw7.3 Sarpol-e Zahab Earthquake on November 12, 2017. 5th Edition, Tehran, Iran. Road, Housing and Urban Research Center (BHRC), (2017).
Lee, G., Wasilewski, F., Gommers, R., Wohlfahrt, K., O’Leary, A., and Nahrstaedt, H. (2006) PyWavelets - Wavelet Transforms in Python, [Online; accessed 2018-MM-DD].
Das, B. and Ramana, G. (2010) Principles of Soil Dynamics, 2nd Edn. Cengage Learning. Inc, Boston.
Darendeli, M.B. (2001) Development of a New Family of Normalized Modulus Reduction and Material Damping Curves.
Gunturi, V.R. and Elgamal, A.-W. (1998) A class of inhomogeneous shear models for seismic analysis of landfills. Soil Dynamics and Earthquake Engineering, 17(3), 197-209.
Gazetas, G. (1987) Seismic response of earth dams: some recent developments. Soil Dynamics and Earthquake Engineering, 6(1), 2-47.
Dakoulas, P. and Gazetas, G. (1985) A class of inhomogeneous shear models for seismic response of dams and embankments. International Journal of Soil Dynamics and Earthquake Engineering, 4(4), 166-182.
BHRC (2014) Iranian Code of Practice for Seismic Resistant Design of Buildings. 4th Edition, Road, Housing and Urban Research Center, Tehran, Iran.