Effect of the Adjacent Topographies on Seismic Site Response

Document Type : Articles

Authors

1 Shahid Rajaee Teacher Training University, Tehran, Iran

2 , Shahid Rajaee Teacher Training University, Tehran, Iran

Abstract

Topography can have significant effects on the seismic ground response during an earthquake. Fortunately, the topography effect on the seismic motion is considered more in recent years and seismic design regulations and guides include this factor; however, study about many aspects of this complicated factor is essential to reduce unforeseen damages caused by earthquakes or any seismic motion in topographical areas. A single topographic irregularity (a canyon or a hill) has been studied by many researchers, and many realistic applications are also found. Nevertheless, to the best of our knowledge, few studies deal with the interaction of topographic irregularities. The aim of this study is to determine how a series of irregularities interact as compared to a single irregularity. When a seismic motion happens in a topographical area, seismic waves are trapped and reflected between the topographic features because of the surrounding topography. Therefore, the interaction between topographies can amplify the seismic ground response. In order to reveal how the interaction between topographies influence on seismic response, several numerical finite element studies have been performed by ABAQUS program, the results of which are presented in the form of the time history and dimensionless graphs. Due to the evaluate effect of geometry type, height, length and angle of slope on the seismic response; rectangular, trapezoidal and triangular topographies are studied with different heights (20-100 m) and different angles (15-75 degrees). As the result of these simulations, although seismic ground motion amplification of the various geometries (rectangular, trapezoidal and triangular topography) is different, the total trend is similar. It means that increasing slope height, length and angle of all types of geometry has agreatereffect on seismic response amplification. In order to study the interaction of topographic irregularities, several models with different numbers of topographies are evaluated. Models are series of triangular topographies with the height of 100m and slope angle of 30°. Distance between each of the topographies is 10 m, and the total length of topographic irregularities is about 1079.2 m. Shear Wave Velocity (VS) is 560 m/s. In this study, different numbers of topography in different distance of seismic source are evaluated. Applied Seismic motion is the record of Manjil earthquake in horizontal direction. Besides, models are two-dimensional and flexible. In many studies, different kinds of energy absorbing boundaries have been investigated and results show that the best boundary conditions is infinite element method. ABAQUS infinite elements can be used to define infinite boundaries in the dynamic problems. These elements have Elastic behavior and absorb the wave energy so that they act as absorbent boundaries. Researchers such as Nielsen, Preisig and Jeremic Have examined the performance of these elements. Modal analysis in Abaqus software has been done to determine the natural frequencies of the soil site. Soil damping is related to strain and differs in the diverse strain levels. Therefore,average of the soil critical dampingratio is assumed 5%. Application of the critical dampingratio is depreciation of the seismic waves reflected from the model boundaries. When the natural frequencies of the soil site are determined,๐›ผ๐‘…and ๐›ฝ๐‘…(Riley damping coefficients) can be calculated. The results show that site seismic response is very different when there is no topographic irregularity between the seismic source and the site; in comparison with several topographic irregularities exist between them. Further topographic features between the seismic source and the site would cause further seismic motion amplification and is so tangible for the hills far away from the source and the ridges. Importance of this issue is because the greater number of topographic irregularities are caused the greater value of seismic motion amplification and in reality, there is a series of topographic irregularities together. Although changes rate of the acceleration dimensionless graphs is greater than velocity and both are greater than displacement dimensionless graphs, their trend changes are similar to each other. It means that surroundings topography (topographies interaction) have effects on site acceleration more than site velocity and displacement. Finally, it is concluded that topographies interaction factor (surrounding topography) should be considered as an effective and independent parameter of a single topography, while the seismic regulations has not paid enough attention to this problem.

Keywords


  1. Buech, F., Davies, T.R., and Pettinga, J.R. (2010) The Little Red Hill seismic experimental study: topographic effects on ground motion at a bedrock-dominated mountain edifice. Bulletin of the Seismological Society of America, 100(5A), 2219-2229.
  2. Pagliaroli, A., Lanzo, G., and Dâย€ย™Elia, B. (2011) Numerical evaluation of topographic effects at the Nicastro ridge in Southern Italy. Journal of Earthquake Engineering, 15(3), 404âย€ย“32.
  3. Kaiser, A., Holden, C., and Massey, C. (2011) Determination of site amplification, polarization and topographic effects in the seismic response of the Port Hills following the 2011 Christchurch earthquake. NZSEE Conference GNS Science, Avalon, and Lower Hutt.
  4. Del Gaudio, V. and Wasowski, J. (2011) Advances and problems in understanding the seismic response of potentially unstable slopes. Engineering Geology, 122(1-2), 73âย€ย“83.
  5. The U.S. Geological Survey and the National Oceanic and Atmospheric Administration. (1971) The San Fernando, California, Earthquake of February 9, United States. U.S. Govt. Print. Off. 254p.
  6. Douglas, H., Christense, L., and Ruf, J. (1986) Rupture process of the March 3, 1985 Chilean earthquake. Geophysical Research Letter, 13(8), 721âย€ย“724.
  7. Messaoudi, A., Laouami, N., and Mezouer, N. (2012) Topographic effects on the seismic responses of slopes. 15th World Conference on Earthquake Engineering, Lisbon.
  8. Assimaki, D., Kausel, E., and Gazetas, G. (2005) Soil-dependent topographic effects: a case study from the 1999 Athens earthquake. Earthquake Spectra, 21(4), 929âย€ย“966.
  9. Gazetas, G., Kallou, P.V., and Psarpopoulos, P.N. (2002) Topography and soil effects in the MS 5.9 Parnitha (Athens) earthquake: the case of Adames. Natural Hazards, 27, 133âย€ย“169.
  10. Uttekar, S.D. and Nayak, C.R. (2016) A review on seismic response of RC building on sloping ground. International Journal of Engineering Research, 5, 701-704.
  11. Hartzell, S.H., Carver, D.L., and King, K.W. (1994) Initial investigation of site and topographic effects at Robinwood Ridge, California. Bulletin of the Seismological Society of America, 84, 1336âย€ย“1349.
  12. Geli, L., Bard, P., and Jullien, B. (1988) The effect of topography on earthquake ground motion: a review and new result. Bulletin of the Seismological Society of America, 78(1), 42-63.
  13. Sanchez-Sesma, F.J. (1987) Site effect on strong ground motion. Soil Dynamics and Earth Engineering, 6(2), 124-132.
  14. Ghayamghamian, M.R. (2005) Segmental cross-spectrum as a new technique in site response estimation using spectral ratio analysis. Journal of Earthquake Engineering, 9(2), 247-261.
  15. Kramer, S.L. (1996) Geotechnical Earthquake Engineering. Prentice Hall, New Jersey
  16. Vidale, J., Bonamassa, O., and Houston, H. (1991) Directional site resonance observed from the 1 October 1987 Whittier Narrows, California, earthquake and the 4 October aftershock. Earthquake Spectra, 7(1), 107-125.
  17. Bonamassa, O. and Vidale, J. (1991) Directional site resonances observed from aftershocks of the 18 October 1989 Loma Prieta earthquake. Bulletin of the Seismological Society of America, 81(5), 1945-1957.
  18. Seed, H.B., and Idriss, I.M. (1970) Soil Moduli and Damping Factors for Dynamic Response Analyses. Report No. ERRC 70-10, Earthquake Engineering Research Center, University of California, Berkeley, California.
  19. Boore, D. (1972) A note on the effect of simple topography on seismic SH wave. Bulletin of the Seismological Society of America, 62(1), 275-284.
  20. Boore, D. (1973) The effect of simple topography on seismic waves: implications for the accelerations recorded at Pacoima Dam, San Fernando Valley, California. Bulletin of the Seismological Society of America, 63(5), 1903-1973.
  21. Davis, L. and West, L. (1973) Observed effects of topography on ground motion. Bulletin of the Seismological Society of America, 63(1), 283-208.
  22. Bouchon, M. (1973) Effect of topography on surface motion. Bulletin of the Seismological Society of America, 63, 615-632.
  23. Sitar, N. and Clough, G.W. (1983) Seismic response of steep slopes in cemented soils. J.
  24. Geotech. Eng., ASCE, 109, 210-227.
  25. Jibson, R.W. (1987) Summary of Research on the Effects of Topographic Amplification of Earthquake Shaking on Slope Stability. US Geological Survey Open-File Report, Menlo Park, CA, 87âย€ย“268.
  26. Kamalian, M., Jafari, M.K., Sohrabi-bidar, A., and Gatmiri, B. (2003) On time-domain two-dimensional site response analysis of topographic structures by BEM. Journal of Seismology and Earthquake Engineering, 5, 2-35.
  27. Kamalian, M., Jafari, M.K., Sohrabi-bidar, A., Razmkhah, A., and Gatmiri, B. (2006) Time-domain two-dimensional site response analysis of non-homogeneous topographic structures by a hybrid BE/FE method. Journal of Soil Dynamics and Earthquake Engineering, 26, 753-765.
  28. Kamalian, M., Jafari, M.K., and Sohrabi-Bidar, A. (2007) Seismic behavior of 2D semi-sine shaped hills against vertically propagating incident waves. Journal of Computational Methods in Engineering (JCME), 26(1), 109-130 (In Persian).
  29. Kamalian, M., Mohazzab, K., Sohrabi Bidar, A., and Haghshenas, E. (2012) Seismic behavior of 2D semi-sine shaped hills against vertical SV waves. Journal of Computational Methods in Engineering (JCME), 31(1), 25-45 (in Persian).
  30. Ducellier, A. and Hideo, A. (2012) Interactions between topographic irregularities and seismic ground motion investigated using a hybrid FD-FE method. Bull. Earthquake Engineering, 18,773-792.
  31. Jafarzadeh, F., Shahrabi, Mohammad Mahdi, and Farahi Jahromi, H. (2015) On the role of topographic amplification in seismic slope instabilities. Rock Mechanics and Geotechnical Engineering, 7(2), 163-170.
  32. Building and Housing Research Center (2015) Iran National Standard No. 2800 (in Persian).
  33. Eurocode 8 (2004) Design of Structures for Earthquake Resistance. The European Union per Regulation.
  34. Jalil, W. (1992) New French seismic code orientation. 10th Word Conference, Earthquake Engineering, Madrid.
  35. Field, E.H. and SCEC Phase III Working Group (2000) Accounting for site effects in probabilistic seismic hazard analyses of southern California: Overview of the SCEC Phase III. Bulletin of the Seismological Society of America, 90, 6B, S1- S31.
  36. Foccioli, E. (1996) Site effect in the Eurocode 8. Eleventh World Conference on Earthquake Engineering, ACAPULCO.
  37. Hrennikoff, A. (1941) Solution of problems of elasticity by the framework method. Journal of Applied Mechanics, 8(4), 169âย€ย“175.
  38. Courant, R. (1943) Variational methods for the solution of problems of equilibrium and vibrations. Bulletin of the American Mathematical Society, 49, 1âย€ย“23.
  39. Parakash, S. (1981) Soil Dynamics. McGraw-Hill Book Company, USA.
  40. Reddy, J. (1993) An introduction to the finite element method. McGraw- Hill, New York.
  41. Ducellier, A. and Hideo, A. (2012) Interactions between topographic irregularities and seismic ground motion investigated using a hybrid FD-FE method. Bull. Earthquake Engineering, 18,773-792.
  42. Rizzitano, S., Ernesto, C., and Giovanni, B. (2014) Coupling of topographic and stratigraphic effects on seismic response of slopes through 2D linear and equivalent linear analyses. Soil Dynamics and Earthquake Engineering, 67, 66âย€ย“84.
  43. Lysmer, J. and Kuhlemeyer, RL. (1969) Finite dynamic model for infinite media. Journal of Engineering Mechanic Division ASCE 95, 859âย€ย“77.
  44. Nielsen, A.H. (2013) Towards a complete framework for seismic analysis in Abaqus. Engineering and Computational Mechanics, 167(1), 3-12.
  45. Preisig, M. and Jeremic, B. (2005) Nonlinear Finite Element Analysis of Dynamic Soil-Foundation-Structure Interaction. SFSI Report, University of California, Davis.
  46. Thomas, O., Touze, C., and Luminais, Ãย‰. (2007) Nonlinear vibrations of free-edge thin spherical shells: Experiments on a 1:1:2 internal resonance. Nonlinear Dynamics, 49(1-2), 259-284.
  47. Chiu, J.K., Cermak, J.E., and Chou, L.S. (2007) Random decrement based method for modal parameter identification of a dynamic system using acceleration responses. Journal of Wind Engineering and Industrial Aerodynamics, 95(6), 389-410.
  48. Bolton, M.D. and Wilson, J.M.R. (1990) âย€ย˜Soil stiffness and dampingâย€ย™. In: Structural Dynamics, Rotterdam Balkema, 209-216.
  49. Safuan A.R., Ahmad, F.K., Kalatehjari, R., and Nazir, R. (2013) Assessment of soil nailing performance by using finite element and finite difference methods. EJGE, 18, 5881-5894.
  50. Ashford, S.A. and Sitar, N. (1997) Analysis of topographic amplification of inclined shear waves in a steep coastal bluff. Journal of Bulletin of the Seismological Society of America, 87(3), 692âย€ย“700.
  51. Stewart, J.P. and Sholtis, SH.E. (2005) Case study of strong ground motion variations across cut slope. Journal of Soil Dynamics and Earthquake Engineering, 25, 539âย€ย“545.
  52. Ozkahriman, F., Nasim, A., and Wartman, J. (2007) Topographic effects in a centrifuge model experiment. 4th International Conference on Earthquake Geotechnical Engineering, Paper No. 1262.
  53. Geli, L., Bard, P.-Y., and Jullien, B. (1988) The effect of topography on earthquake ground motion: A review and new results. Journal of Bulletin of the Seismological Society of America, 78(1), 42âย€ย“63.
  54. Luo, Y.H., Huang, R., and Wang, Y. (2014) The slope seismic response monitoring of Wenchuan aftershocks in Qingchuan. Nat. Hazards Earth Syst. Sci. Discuss, 2, 4135âย€ย“4161.