Course 1 Short history of seismic-resistant design · P100-3 / 2008 "Cod de proiectare seismică – Partea a III-a - prevederi privind evaluarea seismică a clădirilor existente"

Performance Based Seismic Design

Course 1

Short history of seismic-resistant design

Course notes are available for download athttps://www.ct.upt.ro/studenti/cursuri/stratan/pbsd.htm

History of seismic design codes

First attempts to introduce seismic design provisions in building codes date back to the end of the 19th century –beginning of the 20th century

Reason – major earthquakes that occurred in– 1855, Edo, Japan

– 1891, Mino-Awari, Japan

– 1923, Kanto, Japan

– 1906, San Francisco, USA

– 1908, Messina, Italy


1855 Edo (Japan) earthquake


1891 Mino-Awari (Japan) earthquake


1923 Kanto (Japan) earthquake


1906 San Francisco (California, USA) earthquake


1908 Messina (Italia) earthquake


Earthquake engineering started at the end of the 19th century when some European engineers suggested designing structures with a few percent of the weight of the structure as the horizontal load:F=CW

This idea of seismic design was taken up and developed in Japan at the beginning of the 20th century. In 1914, Sano, a Japanese engineer, developed a quasi-dynamic theory.

On April 18, 1906 a major earthquake struck San Francisco, followed by a wide-spread fire. Although engineers learned explicit lessons from the 1906 earthquake, for the most part these lessons referred to the need for greater fire prevention and for the use of reinforced concrete (instead of timber) as a building material.


June 28, 1925 – Santa Barbara (California, USA)earthquake


June 28, 1925 – Santa Barbara (California, USA)earthquake– Increased interest in earthquake engineering

– December 17, 1925: City Council passed a new building code with a clause requiring buildings to be designed to withstand horizontal forces produced by either earthquakes or wind

– Real beginning of earthquake engineering studies and research in the United States

– 1927: shaking table built at Stanford

– Beginning of 30s: Richter devised a numerical scale for grading

– Instrumentally recorded earthquakes: the local magnitude scale

– 1927: Uniform Building Code (UBC) – lateral forces determined as 7.5%-10% of the sum of permanent and live loads


March 10, 1933 –Long Beach (California, SUA) earthquake


March 10, 1933 – Long Beach (California, SUA) earthquake

– Considerable damage, including school buildings (15 out of 35 schools completely destroyed)

– First strong ground motions

– Development of the concept of response spectra: Maurice Biot. The concept of response spectra was not used in a specific way in building codes until 1952.

1933-1959:

– 1943: Los Angeles Building Code (LABC) – the design requirements of a constant lateral force coefficient – inadequate. Seismic coefficient that was taking into account building flexibility associated with number of stories was introduced.

– 1952: "Lateral Forces of Earthquake and Wind" – period of vibration T of the building was introduced as a means of determining the base shear coefficient C

– 1957: To consider the inherent ductility and energy dissipation capacities of different structures, a coefficient K was introduced in the base shear equation V=KCW, where K values were specified for four types of building construction

History of seismic design codes in Romania

Seismic design codes in Romania (Lungu et. al, 2003):– Instrucţiuni provizorii pentru prevenirea deteriorării construcţiilor

din cauza cutremurelor şi pentru refacerea celor degradate aprobate prin Decizia nr. 84351 din 30 decembrie 1941 dată de Ministerul Lucrărilor Publice şi Comunicaţiilor, 9p.

– Instrucţiuni pentru prevenirea deteriorării construcţiilor din cauza cutremurelor, aprobate prin Decizia nr. 60173 din 19 mai 1945 a Ministerului Comunicaţiilor şi Lucrărilor Publice pe baza avizului Consiliului Tehnic Superior din Jurnalul nr.7/1945, publicate în Monitorul Oficial nr. 120 din 30 mai 1945, 10 p.

– STAS 2923-58 (neaprobat) Prescripţii generale de proiectare în regiuni seismice. Sarcini seismice. Comisia de Standardizare R.P.R., 31 Aug.1958, Vol.1-132 p., Vol.2-97 p.

– Normativ condiţionat pentru proiectarea construcţiilor civile şi industriale din regiuni seismice P.13 - 63, aprobat de Comitetul de Stat pentru Construcţii, Arhitectură şi Sistematizare cu Ordinul nr.306 din 18 iulie 1963, 39 p.


– Normativ pentru proiectarea construcţiilor civile şi industriale din regiuni seismice P.13 - 70, aprobat prin Ordinul nr. 362/N din 31 decembrie 1970, Ministerul construcţiilor Industriale şi Comitetul de Stat pentru Economia şi Administraţia Locală, 63 p.

– Normativ privind proiectarea antiseismică a construcţiilor de locuinţe, social-culturale, agrozootehnice şi industriale P.100 - 78, aprobat prin Ordinul nr.23/IX/ din 15 iunie 1978 al Guvernului şi Consiliului de coordonare a activităţii de investiţii, 57 p.

– Normativ privind proiectarea antiseismică a construcţiilor de locuinţe, social-culturale, agrozootehnice şi industriale P.100 - 81, aprobat prin Decizia nr.83 din 21 iulie 1981 a Biroului executiv al Consiliului Ştiinţific al Institutului de cercetare, proiectare şi directivare în construcţii, 72 p.

– Normativ privind proiectarea antiseismică a construcţiilor de locuinţe, social-culturale, agrozootehnice şi industriale P.100 - 91, aprobat prin Ordinul nr.3/N din 1 aprilie 1991, Ministerul Lucrărilor Publice şi Amenajării Teritoriului (MLPAT) - DCLP, 152 p.


– Normativ privind proiectarea antiseismică a construcţiilor de locuinţe, social-culturale, agrozootehnice şi industriale P.100 - 92, aprobat prin Ordinul nr.3/N din 14 aprilie 1992, MLPAT, 151 p.

– Completarea şi modificarea capitolelor 11 şi 12 din “Normativul privind proiectarea antiseismică a construcţiilor de locuinţe, social-culturale, agrozootehnice şi industriale”P.100 - 92, aprobate prin Ordinul nr.71/N din 7 octombrie 1996, Ministerul Lucrărilor Publice şi Amenajării Teritoriului, 50 p.

– P100-1/2004 "Cod de proiectare seismică - Partea I - Prevederi de proiectare pentru clădiri", – experimental. Aliniat la Eurocode 8.

– P100-1/2006 "Cod de proiectare seismică - Partea I - Prevederi de proiectare pentru clădiri" – final

– P100-1/2013 "Cod de proiectare seismică - Partea I - Prevederi de proiectare pentru clădiri"


The first Romanian seismic resistant design code was developed by E. Titaru and A. Cismigiu in 1954.

Several proposals for Standard no. 2923 were made after 1954, including a preliminary draft, in 2 volumes, in 1958.

In 1963 this pioneering work was converted by the State Committee for Constructions, Architecture and Town Planning into the P13-63 code, published in 4300 copies (39. pag.)


Normalised elastic response spectra for Bucharest –evolution in seismic design codes (Lungu et al., 2003)

P100-92: TC=0.7, 1.0, 1.5MRI = 50 years


P100-1/2006: Vrancea source - TC=0.7, 1.0, 1.6MRI = 100 years

P100-1/2006: shallow sources in Banat with ag = 0.20g and ag = 0.16gMRI = 100 years

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3 3.5 4Perioada T , s

T C=1.0s

2.75/T

b 0 =2.75

T B =0.1 T D =3

8.25/T2


0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3 3.5 4Perioada T , s

T B =0.07 T D =3

5.775/T2

1.925/T

b 0 =2.75

T C=0.7s

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3 3.5 4Perioada T , s

TD =2

8.8/T2

4.4/Tb 0 =2.75

TB =0.16 TC=1.6s

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3 3.5 4Perioada T , s

T B=0.07s

2.1/T

b 0=3

T C=0.7sT D =3

6.3/T2

P100-1/2013: TC=0.7, 1.0, 1.6 (MRI = 225 years)



Nature of seismic action

Earthquakes are a very special type of natural hazard in the sense that they are very rare, low-probability events, whose consequences, when they do occur, are very large in terms of destruction and suffering

A significant feature of earthquake damage is that most of the human and economic losses are due to failures of human-made facilities such as buildings and lifelines.

An unfortunate combination of the following factors can create an earthquake disaster: – Severity of the earthquake ground motion. This depends on: the

earthquake magnitude, source-to-site distance, direction of fault rupture propagation, local site conditions and depth to base rock.

– The size and distribution of the population and economic developments.

– The degree of earthquake preparedness, including comprehensive earthquake risk mitigation programs and their implementation.

Seismic risk

Seismic risk: "the probability that social or economic consequences of earthquakes will equal or exceed specified values at a site, at various sites or in an area during a specified exposure time"

Assessing and controlling seismic risk at any given site requires at least the following:1. Estimating the seismic activity at the site. This requires

identification of all seismic sources.

2. Predicting EQGMs that could significantly contribute to the seismic risk.

3. Evaluating whether the EQGMs could induce (besides direct significant vibratory motions to the entire facility system) any of the following potential hazards at the site or the surrounding region: surface fault ruptures, tsunamis, seiches, landslides and floods.

Seismic risk

4. Predicting whether the predicted EQGMs could induce ground failure, that is, liquefaction, settlement, subsidence, differential compaction, loss of bearing and shearing strength and lateral spreading.

5. Assessing the performance of the facility system under the direct and indirect effects of the predicted EQGMs and estimating the degree of damage and losses.

6. Evaluating the possibility of the following incidents: fire, flood, release of hazardous materials, environmental impact and other consequences that could affect the built environment.

7. Conducting a cost-benefit analysis of seismic upgrading and replacing existing hazardous facilities.

Evaluation and control of seismic risk is a complex problem

References

P100-1/2013. "Cod de proiectare seismică - Partea I -Prevederi de proiectare pentru clădiri".

P100-3 / 2008 "Cod de proiectare seismică – Partea a III-a - prevederi privind evaluarea seismică a clădirilorexistente"

EN 1998-1:2004. "Eurocode 8: Design of structures for earthquake resistance -Part 1: General rules, seismic actions and rules for buildings".

EN 1998-3: 2004. "Eurocode 8 - Design of structures for earthquake resistance Part 3: Assessment and retrofitting of buildings"

References

Bozorgnia, Z., Bertero V. (2004). "Earthquake engineering: from engineering seismology to performance-based engineering". CRC Press, ISBN 0-8493-1439-9.

"The seismic design handbook, 2nd ed.", Farzad Naeim(ed.), Kluwer Academic Publishers, 2001, ISBN: 0-7923-7301-4.

Lungu, D., Aldea, A., Arion, C., Cornea, T., Văcăreanu, R. (2003). "Hazardul seismic în România", Partea I, cap. 2 din "Construcţii amplasate în zone cu mişcări seismiceputernice". Coordonatori: D. Dubina şi D. Lungu, Orizonturi Universitare, Timişoara.

References

FEMA 350 (2000). "Recommended Seismic Design Criteria for Moment-Resisting Steel Frame Structures", prepared by the SEAOC, ATC, and CUREE Joint Venture for the Federal Emergency Management Agency, Washington, D.C. (FEMA Publication No. 350).

FEMA 356, 2000, "Prestandard and commentary for the seismic rehabilitation of buildings", prepared by the American Society of Civil Engineers for the Federal Emergency Management Agency, Washington, D.C. (FEMA Publication No. 356).

Documents

Course 1 Short history of seismic-resistant design · P100-3 / 2008 "Cod de proiectare seismică – Partea a III-a - prevederi privind evaluarea seismică a clădirilor existente"