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The course will be organized in eight lectures of two hours each and four tutorials, also with a duration of two hours. In each tutorial a homework assignment will be discussed, the students will have to work on the assignment for about a week and to hand it in at the next tutorial.

The grade will be based on the grades obtained in the assignments and on a final exam that may be written or oral.
English and Italian language may be used indifferently for lectures and tutorials.

Understanding earthquake engineering

Programma

 Course Outline

 

1. Historical development of action and response understanding

Ancient perceptions on earthquakes from the origin to the Age of Enlightenment

Robert Hooke and the theory of elasticity

Galileo, Newton and the law of inertia

 

2. Characterization of seismic hazard and action

Tectonics, waves, statistics and probability

Acceleration, velocity, displacement

    • Hazard disaggregation
    • EQ return period vs design life
    • Code zonation vs site specific parameters
    • Time dependent characterization of hazard 
    • Probabilistic vs deterministic characterization of hazard
    • Acceleration, displacement and velocity as intensity parameters 
    • Corner period in displacement response spectrum
    • How to include fault displacement in design?
    • The “maximum credible event”
    • The “construction earthquake”
    • Alternative “code” definitions of hazard

 

3. Historical development of structural design approaches

Demand and capacity after the Messina earthquake

Early evaluation of ground acceleration and response spectra

Structural design, from elasticity to the discover of ductility

Strength demand in modern codes

Capacity design and detailing in modern codes

    • Mechanism hierarchy
    • Adjusting detailing to the level of inelastic deformation
    • Probabilistic aspects
    • Detailing for actions exceeding the design level
    • Simplified approaches
    • Detailing for low ductility demand

 

4. Displacement based design

Performance based design: a philosophical approach

Myths and fallacies in strength and ductility design

Basics of DBD

 

5. Design philosophy in practice

Simplifying structures

Influence of soil structure interaction

Design life

Design intensity

Design limit states

      • Does a distinction between fully operational and operational make any sense?
      • Is repairable damage an option?
      • Is collapse limit state an option?
      • Importance factors vs. expected performance

Design for damage control or avoidance

Simplified design approaches 

Design of non structural elements

      • Damage to non structural elements
      • Action evaluation

Correlation between protection and structural cost

Design for low seismicity

 

6. Design of Structures

Selection of structural type

Building structures

Bridges

Isolation and energy dissipation

  • Structural systems resisting to horizontal actions
  • Materials vs structural forms
  • Performance parameters
  • Use of isolation
  • Use of additional damping
  • Bearings and joints
  • Isolation and energy dissipation devices
  • Simply supported vs continuous deck bridges
  • Arch bridges
  • Cable stayed bridges
  • Suspension bridges

 

7. Analysis philosophy

Stiffness based analysis

Equilibrium based analysis

Conceptual analysis

  • Simple models: how many degrees of freedom?
  • Relevance of floor stiffness on results

Problems with modal analysis

Use and reliability of NLTH analysis

  • When and how to use NLTH
  • Problems with viscous damping
  • Lumped vs distributed parameter systems
  • Consideration and modelling of brittle failure modes

Use and reliability of push over analysis

  • When and how to use pushover analysis
  • Problems with 3D pushover analysis

Checks of refined analysis results

 

8. Risk assessment and strengthening choices

Simple checks of detailed design

Verifications of complex structures

Different standards for design and assessment

Assessment when details and material are known

Assessment approach when details are unknown

  • Use of testing
  • Use of design simulation
  • Use of back analysis

Potential for step change in safety

Foundation assessment

Modification of damage and collapse mode

  • Use of additional elements
  • Local member strengthening
  • Increasing local deformation capacity
  • Changing the damage mode by local weakening

Introduction of base isolation

  • Capacity protection of the existing structure
  • Procedure for devices introduction
  • Recentering problems

Reduction of displacement demand by added damping

Local problems in force transfer

Policies for resources allocation

Svolgimento

Il corso si terrà nell'Aula Didattica 2 presso Eucentre (Via Ferrata) da martedì 8 novembre a giovedì 1 dicembre 2011 dalle ore 18 alle ore 20.

Bibliografia

 Recommended reading

 

  1. Stucchi, M.,  C. Meletti, V. Montaldo, H. Crowley, G. M. Calvi, E. Boschi, Seismic Hazard Assessment (2003-2009) for the Italian Building Code, Bulletin of the Seismological Society of America, Vol. 101, No. 4, pp. 1885–1911, August 2011, doi: 10.1785/0120100130
  2. Calvi, G.M., Uniform Hazard Spectra: ci crediamo ancora dopo Christchurch? (e dopo il Giappone?), Progettazione Sismica, 01, 2011, pp. 3-7
  3. Calvi, G.M., M. Moratti, A. Villani, D. Pietra e R. Pinho, Progettazione sismica di un ponte strallato di grande luce: il South Crossing Bridge in Guayaquil, Ecuador, Progettazione Sismica, 01, 2011, pp. 45-85
  4. Calvi, G.M., D. Pietra e M. Moratti, Criteri per la progettazione di dispositivi di isolamento a pendolo scorrevole, Progettazione Sismica, 03, 2010, pp. 7-30
  5. Calvi, G.M., Engineers Understanding of Earthquakes Demand and Structures Response, in Earthquake Engineering in Europe, Springer Science, 2010, pp. 223-248 or, alternatively Calvi, G.M., A lezione dai terremoti, Progettazione Sismica, 01, 2010, pp. 3-18
  6. Calvi, G.M., T.J. Sullivan and A. Villani, Conceptual Seismic Design of Cable-Stayed Bridges, Journal of Earthquake Engineering, 14, ISS8, 2010, pp. 1139-1171
  7. Progettazione Sismica, 03, 2009 (the whole special issue on the L’Aquila earthquake, available in English and in Italian)
  8. Calvi, G.M. and T.J. Sullivan, A Model Code for the Displacement-Based Seismic Design of Structures, IUSS Press, Pavia, 2009
  9. Calvi G.M., R. Pinho, and G. Magenes, Traditional and innovative methods for seismic vulnerability assessment at large geographical scales, in The 1755 Lisbon earthquake: revisited, L.A. Mendes-Victor, C.S. Sousa Oliveira C.S., J. Azevedo, A. Ribeiro (Eds.), 2008, pp. 197-220
  10. Priestley, M.J.N., G.M. Calvi and M.J. Kowalsky, Displacement Based Seismic Design of Structures, IUSS Press, Pavia, 2007, 740 pp (at least the first three chapters)
  11. Dragoni, M., Terrae Motus, la sismologia da Eratostene allo Tsubami di Sumatra, UTET Libreria, Novara, 2005, 394 pp.

 

References (to be completed and revised)

 

  1. Breventano, S., Trattato del terremoto,(a cura di Paola Albini), IUSSPress, Pavia, 2007
  2. Biot, M. A., Theory of vibration of buildings during earthquakes, Z Angew Matematik Mech, 14(4): 213-23, 1934. Discusso criticamente in: Trifunac, M. D., Biot response spectrum, Soil dynamics and earthquake engineering, 26, 491-500, 2006
  3. A double-slide isolator on curved surfaces, patented by M. Viscardini in 1909, described in: Barucci C, La casa antisismica [The antiseismic house], Gangemi, 1990.
  4. Decreto Legge Luogotenenziale 19 agosto 1917, G.U. 10 settembre 1917
  5. Galilei, G., Dialogo sopra i due massimi sistemi del mondo, Firenze, 1632
  6. Hooke, R., Lectiones Cutlerianæ, or A collection of lectures: physical, mechanical, geographical, & astronomical, Printed for John Martyn, London, 1679
  7. Housner, G.W., Chairman, “Competing against time”, Report to Governor George Deukmejian from the Governor’s Board of Inquiry on the 1989 Loma Prieta Earthquake, Department of General Service, North Highlands, CA, 1990
  8. Istruzioni ed esempi di calcolo delle costruzioni stabili alle azioni sismiche, Giornale del Genio Civile, anno LI, 1913
  9. Il Monitore Tecnico (giornale d’ingegneria, architettura, meccanica, elettrotecnica, ferrovie, agronomia, catasto ed arti industriali – organo ufficiale dell’associazione tra gli ex allievi del Politecnico Milanese), 20 gennaio 1909
  10. Ligorio, P. Libro di diversi terremoti, (a cura di Emanuela Guidoboni), De Luca Editori d’Arte, Roma, 2005
  11. Newton, I. Philosophiae Naturalis Principia Mathematica, London, 1687
  12. Newmark, N. M., and Hall, W. J., Earthquake Spectra and Design, Engineering Monographs, EERI, Oakland, CA, 1982
  13. Plinius, Naturalis Historia, Liber XXXVI, xxi, 95
  14. Priestley, M.J.N., Myths and fallacies in earthquake engineering, revisited. The 9th Mallet Milne Lecture, IUSS Press, Pavia, 2003Regio Decreto 18 aprile 1909, n. 193, pubblicato sulla G.U. n. 95, del 22 aprile 1909
  15. Relazione della Commissione Reale incaricata di designare le zone più adatte per la ricostruzione degli abitati colpiti dal terremoto del 28 dicembre 1908 o da altri precedenti, Tipografia della R. Accademia dei Lincei, Roma, 1909
  16. Rousseau, J.J., Lettera a Voltaire sul terremoto di Lisbona (nota anche come Lettera sulla Provvidenza), 1756
  17. Voltaire, Poème sur le désastre de Lisbonne, ou examen de cet axiome: tout est bien, 1756

Ambito : Scienze e Tecnologie

Semestre: Semestre I

Anno accademico: 2011-2012