Bulletin of Earthquake Engineering

, Volume 16, Issue 12, pp 5769–5800 | Cite as

Hazard-dependent soil factors for site-specific elastic acceleration response spectra of Italian and European seismic building codes

  • G. AndreottiEmail author
  • A. Famà
  • C. G. Lai
Original Research


To define the seismic input in non-liquefiable soils, current seismic standards give the possibility to treat local site effects using a simplified approach. This method is generally based on the introduction of an appropriate number of soil categories with associated soil factors that allow modifying the shape of the elastic acceleration response spectrum computed at rocky (i.e. stiff) sites. Although this approach is highly debated among researchers, it is extensively used in practice due to its easiness. As a matter of fact, for standard projects, this method represents the driving approach for the definition of the seismic input. Nevertheless, recent empirical and numerical studies have risen doubts about the reliability and safety of the simplified approach in view of the tendency of the current soil factors of Italian and European building codes to underestimate the acceleration at the free surface of the soil deposit. On the other hand, for certain soil classes, the current soil factors seem to overestimate ground amplification. Furthermore, the occurrence of soil nonlinearity, whose magnitude is linked to both soil type and level of seismic intensity, highlights the fallacy of using constant soil factors for sites with a different seismic hazard. The objective of this article is to propose a methodology for the definition of hazard-dependent soil factors and simultaneously quantify the reliability of the coefficients specified in the current versions of Eurocode 8 (CEN 2005) and Italian Building Code (NTC8 2008 and revision NTC18 2018). One of the most important outcome of this study is the quantification of the relevance of soil nonlinearity through the definition of empirical relationships between soil factors and peak ground acceleration at outcropping rock sites with flat topological surface (reference condition).


Soil factors Soil nonlinearity Stochastic ground response analysis Eurocode 8 Italian building code (NTC18) 



The work presented in this paper was partly supported by the financial contribution of the Italian Department of Civil Protection within the framework “RELUIS-DPC” which is greatly acknowledged by the authors. Special thanks to Francesca Bozzoni, Laura Scandella, Mirko Corigliano and Claudio Strobbia for providing us the earlier version of the stochastic code used in this study. A special word of appreciation goes to Prof. Sebastiano Foti for very fruitful discussions that triggered the idea of writing this article.


  1. Al Atik L, Abrahamson N, Bommer JJ, Scherbaum F, Cotton F, Kuehn N (2010) The variability of ground motion prediction models and its components. Seismol Res Lett 81(5):794–801CrossRefGoogle Scholar
  2. Alawneh AS, Nusier OK, Al-Mufty AA (2006) Reliability based assessment of shallow foundations using mathcad. Geotech Geol Eng 24:637–660CrossRefGoogle Scholar
  3. Alonso EE (1976) Risk analysis of slopes and its application to slopes in Canadian sensitive clays. Geotechnique 26:453–472CrossRefGoogle Scholar
  4. Anderson JG, Brune JN (1999) Probabilistic seismic hazard assessment without the ergodic assumption. Seismol Res Lett 70(1):19–28CrossRefGoogle Scholar
  5. Andreotti G, Lai CG (2017) A nonlinear constitutive model for beam elements with cyclic degradation and damage assessment for advanced dynamic analyses of geotechnical problems. Part II: validation and application to a dynamic soil–structure interaction problem. Bull Earthq Eng 15:2803–2825CrossRefGoogle Scholar
  6. AndreottiG, Lai CG, Bozzoni F, Scandella L (2013) New soil factors for the Italian Building Code (NTC08) derived from 1D fully stochastic ground response analyses. In: Proceedings XV Symp. L’Ingegneria Sismica in Italia. Padova, ANIDISGoogle Scholar
  7. Arnold P, Fenton GA, Hicks MA, Schweckendiek T, Simpson B (2012) Modern Geotechnical design codes of practice. IOS Press, Amsterdam, p 344Google Scholar
  8. Atkinson GM (2006) Single-station sigma. Bull Seismol Soc Am 96(2):446–455CrossRefGoogle Scholar
  9. Awojobi AO (1975) The settlement of a foundation on Gibson soil of the second kind. Geotechnique 25(2):221–228CrossRefGoogle Scholar
  10. Baecher GB, Christian JT (2003) Reliability and Statistics in geotechnical Engineering. Wiley, ChichesterGoogle Scholar
  11. Barani S, De Ferrari R, Ferretti G, Eva C (2008) Assessing the effectiveness of soil parameters for ground response characterization and soil classification. Earthq Spectra 24(3):565–597CrossRefGoogle Scholar
  12. Becker DE (1996) Limit states design for foundations. Part II. Development for national building code of Canada. Can Geotech J 33(6):984–1007CrossRefGoogle Scholar
  13. Brejda J, Moorman J, Smith TB, Karlen JL, Allan DL, Dao TH (2000) Distribution and variability of surface soil properties at a regional scale. Soil Sci Soc Am J 64:974–982CrossRefGoogle Scholar
  14. Chen Y-H, Tsai C-CP (2002) A new method for estimation of the attenuation relationship with variance components. Bull Seismol Soc Am 92(5):1984–1991CrossRefGoogle Scholar
  15. Corigliano M, Lai CG, Rota M, Strobbia C (2012) ASCONA: automated selection of compatibile natural accelerograms. Earthq Spectra 28(3):965–987CrossRefGoogle Scholar
  16. Darendeli MB (2001) Development of a new family of normalized modulus reduction and material damping curves. Ph.D. thesis, The University of Texas, TexasGoogle Scholar
  17. Det Norske Veritas (DNV) (2012) Statistical representation of soil data, recommended practice report DNV-RP-C207, Det Norske VeritasGoogle Scholar
  18. Duncan JM (2000) Factors of safety and reliability in geotechnical engineering. J Geotech Geoenviron Eng 126:307–316CrossRefGoogle Scholar
  19. European Committee for Standardization (CEN) (2005) Part 1: general rules, seismic actions and rules for buildings, Eurocode 8: design of Structures for Earthquake Resistance, EN 1998-1, BrusselsGoogle Scholar
  20. Fenton GA, Griffiths DV (2003) Bearing capacity prediction of spatially random c–ϕ soils. Can Geotech J 40(1):54–65CrossRefGoogle Scholar
  21. Fenton GA, Griffiths DV (2008) Risk assessment in geotechnical engineering. Wiley, HobokenCrossRefGoogle Scholar
  22. Gibson RE (1967) Some results concerning displacements and stresses in a non-homogeneous elastic half-space. Geotechnique 17(1):58–67CrossRefGoogle Scholar
  23. Gruppo di Mappa di Pericolosità Sismica (GdL MPS) (2004) Redazione della mappa di pericolosità sismica prevista dall’Ordinanza PCM 3274 del 20 marzo 2003, Rapporto conclusivo per il dipartimento di Protezione Civile, INGV, Milano, Roma, 65 pp. +5 appendici, available at (in Italian)
  24. Idriss IM (1990) Response of soft soil sites during earthquakes. In: Proceedings H.B. Seed memorial symposium. BiTech Publishers Ltd, Vancouver, pp 273–290Google Scholar
  25. Idriss IM, Sun JI (1992) SHAKE91: a computer program for conducting equivalent linear seismic response analyses of horizontally layered soil deposits. Program modified based on the original SHAKE program published in December 1972 by Schnabel, Lysmer and Seed, Center for Geotechnical Modeling, Department of Civil and Environmental Engineering, University of California, Davis, CaliforniaGoogle Scholar
  26. Kaklamanos J, Bradley BB, Thompson EM, Baise LG (2013) Critical parameters affecting bias and variability in site-response analyses using KiK-net downhole array data. Bull Seismol Soc Am 103(3):1733–1749CrossRefGoogle Scholar
  27. Kaklamanos J, Baise LG, Thompson EM, Dorfmann L (2015) Comparison of 1D linear, equivalent-linear, and nonlinear site response models at six KiK-net validation sites. Soil Dyn Earthq Eng 69:207–219CrossRefGoogle Scholar
  28. Kausel E, Assimaki D (2002) Seismic simulation of inelastic soils via frequency-dependent moduli and damping. J Eng Mech 128(1):34–47CrossRefGoogle Scholar
  29. Kottke A, Rathje E (2009) Technical manual for STRATA. PEER report 2008/10 University of California, BerkeleyGoogle Scholar
  30. Lumb P (1970) Safety factors and the probability distribution of soil strength. Can Geotech J 7:225–242CrossRefGoogle Scholar
  31. Ministero delle Infrastrutture e dei Trasporti (NTC) (2008) Norme tecniche per le costruzioni, Ministero delle Infrastrutture e dei Trasporti, Decreto Ministeriale del 14 gennaio 2008, Supplemento ordinario alla G.U. n. 29 del 4 febbraio 2008 (in Italian) Google Scholar
  32. Ministero delle Infrastrutture e dei Trasporti (NTC) (2018) Norme tecniche per le costruzioni, Ministero delle Infrastrutture e dei Trasporti, Decreto Ministeriale del 17 gennaio 2018, Supplemento ordinario alla G.U. n. 42 del 20 febbraio 2018 (in Italian) Google Scholar
  33. Mohammadioum B, Pecker A (1984) Low frequency transfer of seismic energy by superficial soil deposits and soft rocks. Earthq Eng Struct Dynam 12:537–564CrossRefGoogle Scholar
  34. Morikawa N, Kanno T, Narita A, Fujiwara H, Okumura T, Fukushima Y, Guerpinar A (2008) Strong motion uncertainty determined from observed records by dense network in Japan. J Seismol 12(4):529–546CrossRefGoogle Scholar
  35. Peruš I, Fajfar P (2014) Prediction of site factors by a non-parametric approach. Earthq Eng Struct Dyn 43(12):1743–1761CrossRefGoogle Scholar
  36. Phoon KK, Kulhawy FH, Grigoriu MD (1995) Reliability based design of foundations for transmission line structures. Report TR-105000. Electric Power Research Institute, PaloAltoGoogle Scholar
  37. Pitilakis KD, Gazepis C, Anastasiadis A (2006) Design response spectra and soil classification for seismic code provisions. In: Proceedings, ETC-12 workshop, January 20–21, 2006, AthensGoogle Scholar
  38. Pitilakis K, Riga E, Anastasiadis A (2012) Design spectra and amplification factors for Eurocode 8. Bull Earthq Eng 10(5):1377–1400CrossRefGoogle Scholar
  39. Pitilakis K, Riga E, Anastasiadis A (2013) New code site classification, amplification factors and normalized response spectra based on a worldwide ground-motion database. Bull Earthq Eng 11(4):925–966. CrossRefGoogle Scholar
  40. Pitilakis K, Riga E, Anastasiadis A (2015) New design spectra in eurocode 8 and preliminary application to the seismic risk of Thessaloniki, Greece. In: Ansal A, Sakr M (eds) Perspectives on earthquake geotechnical engineering. Geotechnical, geological and earthquake engineering, vol 37. Springer, ChamGoogle Scholar
  41. Rey J, Faccioli E, Bommer JJ (2002) Derivation of design soil coefficients (S) and response spectral shapes for Eurocode 8 using the European Strong-Motion Database. J Seismol 6(4):547–555CrossRefGoogle Scholar
  42. Rota M, Zuccolo E, Taverna L, Corigliano M, Lai CG, Penna A (2012) Mesozonation of the Italian territory for the definition of real spectrum-compatible accelerograms. Bull Earthq Eng 10:1357–1375CrossRefGoogle Scholar
  43. Santamarina JC, Klein KA, Fam MA (2001) Soils and waves—particulate materials behavior, characterization and process monitoring. Wiley, ChichesterGoogle Scholar
  44. Seber GAF, Wild CJ (2003) Nonlinear regression. Wiley-Interscience, HobokenGoogle Scholar
  45. Seed HB, Idriss IM (1971) Simplified procedure for evaluating soil liquefaction potential. J Soil Mech Found Div 97(9):1249–1273Google Scholar
  46. Suetomi I, Yoshida N (1998) Nonlinear behavior of surface deposit during the 1995 Hyogoken-Nambu earthquake. Soil and Foundations, special issue no. 2, Sep, 11–22Google Scholar
  47. Tobutt DC (1982) Monte Carlo simulation methods for slope stability. Comput Geosci 8:199–208CrossRefGoogle Scholar
  48. Wu XZ (2013) Trivariate analysis of soil ranking-correlated characteristics and its application to probabilistic stability assessments in geotechnical engineering problems. Soils Found 53:540–556CrossRefGoogle Scholar
  49. Yoshida N, Kobayashi S, Suetomi I, Miura K (2002) Equivalent linear method considering frequency dependent characteristics of stiffness and damping. Soil Dyn Earthq Eng 22(3):205–222CrossRefGoogle Scholar
  50. Zembaty Z, Kokot S, Bozzoni F, Scandella L, Lai CG, Kuś J, Bobra P (2015) A system to mitigate deep mine tremor effects in the design of civil infrastructure. Int J Rock Mech Min Sci 1(74):81–90CrossRefGoogle Scholar

Copyright information

© Springer Nature B.V. 2018

Authors and Affiliations

  1. 1.University School for Advanced Studies IUSS PaviaPaviaItaly
  2. 2.Department of Civil Engineering and ArchitectureUniversity of PaviaPaviaItaly
  3. 3.European Centre for Training and Research in Earthquake EngineeringPaviaItaly

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