SEISMIC HAZARD ASSESSMENT - methodology and application · 2011-11-30 · - Bohemian Massif - Western Carpathians Bohemian Massif is morphologically distinct unit of Central Europe

SEISMIC HAZARD ASSESSMENT

- methodology and application

to the city Plzeň (Pilsen)

Kateřina Demjančuková

University of West Bohemia

Faculty of Mechanical Engineering

Department of Power System Engineering

Pilsen, Czech Republic

24. 11. 2011

SEISMIC ENGINEERING KNOWLEDGE TRANSFER SEMINAR 21 – 25 November 2011, NRI Rez, Czech Republic

Seismic Engineering Knowledge Transfer

Seminar, 21 - 25 November 2011, NRI Rez,

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CONTENTS

Seismic hazard and seismic risk

Geological structure of the Czech Republic

Bohemian Massif

Focal regions in Central Europe

Input data, seismic catalogue

Methodology of seismic hazard assessment

Example of seismic hazard assessment – Plzeň (Pilsen) city



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Seismic Hazard and Seismic Risk

Seismic hazard of the locality is characterized as the size of

earthquake (measured by the intensity of earthquake or

maximum acceleration of seismic waves) that can be expected

during the specified time period in the specified locality with

the probability equal to a specified value. This value is usually

95%.

- is related to risk sources.

Seismic risk is a set of effects that will appear in case of an

earthquake. Seismic risk is characterised by the seismic hazard

of the locality and by the fragility of structures and

technological equipment and by the bedrock in real facility.

- is related to protected interests



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Seismic Hazard and Seismic Risk



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Geology of the Czech Republic



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The territory of the Czech Republic consists of

- Bohemian Massif

- Western Carpathians

Bohemian Massif is morphologically distinct unit of Central

Europe.

Bohemian Massif is created by structural belts predominantly of

the SW – NE strike that are divided by faults of the NW – SE

strike into crustal blocks.

The parameter of attenuation of intensities with distance of

Bohemian Massif is very low.

Bohemian Massif



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Focal regions in Central Europe I.



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1 –Thüringer – Wald Gera

2 – Kraslice – Aš – Plauen

3 – Komořany – Leipzig

4 – Zittau – Bautzen (Upper Lausicz)

5 – Trutnov – Klodsko – Strzelin-

Šumperk

6 – Regensburg – Augsburg

7 – Domaţlice – Tachov

8 – Šumava – Grafenau – Thalberg

9 – Kaplice – Freistadt

10 – Waidhofen – Jindřichův Hradec

11 – Jihlava and vicinity

12 – Vysoké Mýto – Litomyšl – Svitavy

13 – Innsbruck and vicinity

14 – Salzach – St. Martin

15 – Linz – Pregarten – Molln –

Neulengbach

16 – Bolzano – Lienz

17 – Friuli

18 – Eastern Alps

Focal regions in Central Europe II. 19 – Český Těšín – Opava

20 – Malé and Biele Karpaty Mts.

21 – Trenčín – Ţilina

22 – Martin – Prievidza – Banská

Bystrica- Dolný Kubín

23 – Keţmarok – Zakopané – Krakow

24 – Prešov – Košice – Humenné

25 – Uţgorod – Mukačevo – Beregovo

26 – Graz – Maribor – Oberschützen –

Sopron – Kapuvár

27 – Körmand – Györ

28 – vicinity of Komárno

29 – Nagykanisza – Mór

30 – Budabest – Monór – Jászbereny

31 – Mátra Mts. and the vicinity

32 – Zemplín – Tokaj

33 – Kaposvár – Dunaföldvár

34 – Keczkmet – Szolnok

35 – Békés – Gyula

36 – Oradea – Satu Mare

A – Western Margin of Bohemian

Massif

B – Central Part of the Bohemian

Massif

C – Moravia and Vienna basin

D – Lower and Upper Silesia

E – Central Slovakia

F – Nové Zámky – Levice –

Banská Štiavnica

G – Revúca – Roţňava – Miskolc

H – Debrecen – Szeged –

Csongrád

I – Russian table

J – NW Romania



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Seismic hazard assessment for a specific locality means the

assessment of the intensity of an earthquake that repeats in

defined time (period).

In practise, there are two approaches used to describe the

frequency of repeating events. First of them is the return period,

second one is the annual exceedence probability (probability that a

real intensity of earthquake will occur in either of given year).

For calculations of repeated disasters we can use:

empiric data distribution, most commonly approximated with the log-

normal distribution of frequency of occurence according to the size,

in case of low probability of occurence of earthquake in certain time

interval, total sum of events during the time interval is replaced by

binomial (Bernoulli) distribution or Gumbel distribution function.

Seismic hazard assessment



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First we need to collect and validate data.

Then we can create the time serie for the occurrence of disaster.

Data set can be improved and refined by installing of monitoring.

Observation of the occurrence of disaster in the region in time enables us

to create the frequency graph.

PROBLEM No. 1 : INPUT DATA

According to the catalogues [4, 5] we observe that in central Europe

earthquakes (with intensity Io in epiceter) were enregisterd.

Io 8° MSK-64 approximately from 13th century,

Io 7° MSK-64 approximately from 14th century,

Io 6° MSK-64 approximately from the beginning of 16th century,

Io 5° MSK-64 approximately from the half of 19th century,

Io 4° MSK-64 from 20th century.

Methodology - Input data I.



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Input data II.

1763 (May), Komárno (Engraving demonstrating the most destructive earthquake on the territory of ancient Czechoslovakia,

7-8° MSK-64 source: http://www1.ig.cas.cz)

1896 – imperial decree: duty of the police to collect data about the occurences of EQs

http://www1.ig.cas.cz/



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Seismic Catalogue Data for the seismic hazard assessment were chosen from the catalogue

included in [4] – data for intensity Io 6o in the circle with radius 400 km

around the city of Plzeň.

Generally, according to the standards, the radius is 200 – 400 km, but in

case of Bohemian Massif, we have to take the upper limit with regard to the

low parameter of attenuation of intensities with distance.

Plzeň (Pilsen) - town situated in the western part of the Czech Republic

Demonstration of data table:

Date Time (GMT) Epicentral coordinates

Focal

depth

Epicentral

intensity Magnitudo Notes

h-hour, m-minute, s-second ° N ° E h [km] Io ° [MSK-64] M (focal region)

456 47.23 16.62 9 6.2 27

26.3.1511 19-19h30m 46.2 13.4 20 10,50 7.2 17

6.2.1788 07h 49.88 12.75 6 7

29.6.1961 11h52m49s 50.82 10.11 6 4 A



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Methodology - Seismic Catalogue for Plzeň



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Example of Plzeň (Pilsen) city

– Fraquency graph

Frequency graph

- an empiric function describing the distribution of number of earthquakes according to the earthquake intensity.

- intensity of an earthquake is expressed by the epicentral intensity Io,

- the cummulative frequency of an earthquake which means the number of all earthquakes with epicentral intensity equal or greater the given intensity Io is used.

Cummulative frequency graphs for a given region (locality) are based on data from earthquake catalogues.



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Frequency graph

Frequency graph - Plzen city

1

10

100

1000

6 7 8 9 10 11

Intensity Io [MSK-64]

Cu

mm

ula

tive f

req

uen

cy N

c [

-]



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Example of Plzeň (Pilsen) city – Map of maximum

observed intensities

Map of seismic regions of the Czech Republic (intensity of 7 MSK-64 - densely hatched,

intensity 6 MSK-64 - sparsely hatched, intensity of 5 MSK-64 - not hatched )



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Calculation of hazard based on the extreme value method is the equation

Rt (Io Ioi) = 1 - {T / [ T + t .P (Io Ioi)]}n+1.

T … the time period of disaster observation,

n … is the number of observed occurences of the defined type of disaster,

P … defined by equation

P (Io Ioi ) = [exp (- Ioi) - exp (- Iomax)] : [exp (- Iomin) - exp (- Iomax)].

Iomi … value of the minimum intensity (for witch the catalogue is

complete),

Iomax … value of the maximum intenstity of the disaster in the real region

Iomin Ioi Iomax.

Parameter = b ln 10, where b is the argument from the frequency equation

log Nc = a - b Ioi

Nc ... cummulative frequency (summarized from the maximum intensity).

EXTREME VALUE METHOD



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Rt(Io Ioi) is the probability that the intensity of disaster Io won‘t pass the

intensity Ioi in time interval t and P(Io Ioi ) is the probability that the

intensity of disaster Io will pass the value Ioi.

Example of calculation of basic curves:

Seismic hazard assessment

Probabilities of earthquake occurrence expressed by curves of non-exceedance Rt(Io ≥ Ioi) in

dependence on time interval length for given site. P – the probability of occurrence of earthquake with

intensity Io and Rt (Io ≥ Ioi) are probabilities, which mean, that in the time interval t the value Ioi will not

be exceeded.



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Conclusion

The methodology of seismic hazard assessment was

presented.

Several problems connected to the seismic hazard

assesment were discused.

Current and next results will be used for solving LOCA

redefinition problem.



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References

1. Betbeder-Matibet, J., Seismic engineering, ISTE Ltd, John Wiley & Sons, Inc. , 2008, ISBN 978-1-84821-026-4.

2. PROCHÁZKOVÁ D.: Analýza a řízení rizik. ISBN 978-80-01-04841-2. Karolinum, Praha 2011, 386p.

3. PROCHÁZKOVÁ D.: Seismické inţenýrství na prahu třetího tisíciletí. SPBI SPEKTRUM XII Ostrava 2007, ISBN 978-80-7385-022-7, 25p.+CD-ROM.

4. PROCHÁZKOVÁ, D.: Regionální katalog zemětřesení s Io > 6° MSK- 64 (M> 4).

5. PROCHÁZKOVÁ, D.: Metody, nástroje a techniky pro rizikové inţenýrství.ISBN 978-80-01-04842-9. Karolinum, Praha 2011, 289p.



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Documents

SEISMIC HAZARD ASSESSMENT - methodology and application · 2011-11-30 · - Bohemian Massif - Western Carpathians Bohemian Massif is morphologically distinct unit of Central Europe