CITY OF BUCHAREST SEISMIC PROFILE - CiteSeerX

SEISMIC STRENGTHENING OF BUILDINGS AND SEISMIC INSTRUMENTATION -TWO PRIORITIES FOR SEISMIC RISK

REDUCTION IN ROMANIA

D. Lungu1,2 , A. Aldea2, S. Demetriu2 and I. Craifaleanu1

Abstract

According to the number of people lost in earthquakes during XXth century as well as in a single (March 4, 1977) earthquake during this century (1574 people, including 1424 in Bucharest), Romania can be ranked the 3rd country in Europe, after Italy and Turkey. Romania is followed by the former Yugoslavia and by the Greece (Bolt, 1995, Coburn and Spence, 1992).

The World Bank loss estimation after the 1977 earthquake (Report No.P-2240-RO, 1978) indicates that from the total loss (2.05 Billion US $) more than 2/3 was in Bucharest, where 32 tall buildings collapsed. Half of the total loss was accumulated from buildings damage. The 1977 direct loss and indirect consequences of loss mark probably the starting point of economical decay of Romania during the next decade. They also explain the present concern of civil engineers and Romanian Government for assessment and reduction of seismic risk in Romania.

The World Map of Natural Hazards prepared by the Münich Re, 1998 indicates for Bucharest: “Large city with Mexico-city effect”. The map focuses the dangerous phenomenon of long (1.6s) predominant period of soil vibration in Bucharest during strong Carpathians Vrancea earthquakes. The Bucharest and Lisbon are the only two European cities falling into Mexico-city category.

International experts and organizations agreed that Bucharest is the capital city in Europe characterised by the highest seismic risk. The paper presents: Part I, Vrancea Seismic Hazard Assessment in Romania, 1.1 Subcrustal Seismicity of the Vrancea Region; 1.2 Codes and standards for design of earthquake resistance of structures

1 National Institute for Building Research, Bucharest, Tel.: 0040.21.255.02.70, Fax: 0040.21.255.00.62, E-mail: [email protected]; [email protected] 2 Technical University of Civil Engineering, Bucharest. Tel.: 0040.21.242.58.04, E-mail: [email protected]

mailto:[email protected]

mailto:[email protected]

(1940 – 2000); 1.3 Seismic hazard assessment in the draft P 100 2003 seismic code of Romania. Part II, Seismic Risk Management, 2.1 The structure of the existing building stock in Bucharest; 2.2 Fragile residential buildings in Bucharest.

Part I: Vrancea seismic hazard assessment in Romania

1.1 Subcrustal seismicity of the Vrancea region of Romania

The Vrancea region, located where the Carpathians Mountains Arch bends, at about 135 ± 35 km epicentral distance from Bucharest, is a source of subcrustal seismic activity, which affects ±35 more than 2/3 of the territory of Romania and an important part of the territories of Republic of Moldova, Bulgaria and Ukraine. The Vrancea source induces the very high seismic risk in the densely built zones of the South-East of Romania. According to the 20th century seismicity, the epicentral Vrancea area is confined to a rectangle of 40x80km2 having the long axis oriented N45E and being centered at about 45.6o Lat.N and 26.6o Long. E.

During the last 60 years, Bucharest was threatened by 4 strong Vrancea events: Nov.10, 1940 (moment magnitude Mw=7.7, focal depth h=150 km), March 4, 1977 (Mw=7.5, h=109 km), Aug 30, 1986 (Mw=7.2, h=133km) and May 30/31, 1990 (Mw=7.0/6.4, h=91/79 km).

The Catalogues of earthquakes occurred on the territory of Romania were compiled by Radu (1974, 1980, 1995) and Constantinescu and Marza (1980, 1995).

The most complete Vrancea historical catalogue is Radu Catalogue, even the majority of significant events are also included in Constantinescu and Marza Catalogue. The Radu Catalogue is about three times larger than the other Catalogue. The magnitude used in the Radu catalogue is the Gutenberg-Richter magnitude, M.

Figure 1. Epicenters of earthquakes in Romania, 984 - 2000

For Vrancea subcrustal source, the conversion of Gutenberg-Richter magnitude into moment magnitude might be approximated by Mw = M + 0.3 for 6.5 < Mw < 7.8 (Lungu et al.1999). From existing catalogues, one may approximately note:

(i) During the time interval 984-1900, one event/century with epicentral intensity I0 ≥ 9.0;

(ii) During the period 1901-2000 the evidence is two events per century of intensity I0 ≥ 9.0 (i.e. Mw ≥ 7.5), Table 1. Table 1. 20th Century catalogue of Vrancea Earthquakes, MGR>6.0

RADU Catalogue, 1994

MARZA Catalogue,

1980

www.infp.roCatalogue,

1998 Date

Time (GMT) h:m:s

Lat. No Long. Eo

h, km I0 MGR Mw I0 Ms Mw

1903 13 Sept 08:02:7 45.7 26.6 >60 7 6.3 - 6.5 5.7 6.3 1904 6 Feb 02:49:00 45.7 26.6 75 6 5.7 - 6 6.3 6.6 1908 6 Oct 21:39:8 45.7 26.5 150 8 6.8 - 8 6.8 7.11912 25 May 18:01:7 45.7 27.2 80 7 6.0 - 7 6.4 6.7 1934 29 March 20:06:51 45.8 26.5 90 7 6.3 - 8 6.3 6.6 1939 5 Sept 06:02:00 45.9 26.7 120 6 5.3 - 6 6.1 6.2 1940 22 Oct 06:37:00 45.8 26.4 122 7 / 8 6.5 - 7 6.2 6.5 1940 10 Nov 01:39:07 45.8 26.7 1501) 9 7.4 - 9 7.4 7.7 1945 7 Sept 15:48:26 45.9 26.5 75 7 / 8 6.5 - 7.5 6.5 6.8 1945 9 Dec 06:08:45 45.7 26.8 80 7 6.0 - 7 6.2 6.5 1948 29 May 04:48:55 45.8 26.5 130 6 / 7 5.8 - 6.5 6.0 6.3 1977 4 March 2) 19:22:15 45.34 26.30 109 8 / 9 7.2 7.5 9 7.2 7.4 1986 30 Aug 21:28:37 45.53 26.47 133 8 7.0 7.2 - - 7.1 1990 30 May 10:40:06 45.82 26.90 91 8 6.7 7.0 - - 6.9 1990 31 May 00:17:49 45.83 26.89 79 7 6.1 6.4 - - 6.4

The strongest Vrancea earthquake ever occurred is accepted to be the Oct 26, 1802 event (M = 7.5 ….7.7) the most disastrous event is March 4, 1977 earthquake (M=7.2; Mw=7.4 …7.5).

The recurrence-magnitude relationship is determined from Radu’s 20th century Catalogue of subcrustal magnitudes with threshold lower magnitude Mw=6.3. The average number per year of Vrancea subcrustal earthquakes with magnitude equal to and greater than Mw, as resulting also from Figure 2 is (Lungu, Demetriu, 1995):

log n(>Mw) = 3.76 - 0.73 Mw (1a)

The maximum credible magnitude of the source was estimated using Wells and Coppersmith (1994) equations. Even those equations are intended for crustal earthquakes, the experience of recent subcrustal Vrancea events fits approximately the mentioned equations. According to Romanian geologists Sandulescu & Dinu, in Vrancea subduction zone the length of the rupture surface is: SRL ≤ 150÷200 km and the area of the rupture surface is: SRA≤8000 km2. Based on this estimation, one might get from Wells and Coppersmith equations Mw,max= 8.0...8.1 (Lungu et al. 1999).

If the source magnitude is limited by an upper bound magnitude Mw,max, the recurrence relationship (1a)can be modified in order to satisfy the property of a probability distribution (Hwang and Huo 1994). In the case of Vrancea source (Elnashai and Lungu, 1995):

( ) )3.61.8(687.1

)M1.8(687.1M687.1654.8

w e1e1eMn

ww

−−

−−−

−−=≥ (1b)

http://www.infp.ro/

In Eq.(1), the threshold lower magnitude is Mw0=6.3, the maximum credible magnitude of the source is Mw,max=8.1, and α = 3.76 ln10 = 8.654, β = 0.73 ln10 =1.687.

Figure 2. Magnitude recurrence relation for the subcrustal Vrancea source (Mw ≥ 6.3)

1.2 Codes and standards for design of earthquake resistance of structures (1940 – 2000)

The codes for earthquake resistance of buildings and structures in Romania during the last 60 years are listed below:

P.I. - 1941 Preliminary instructions (after the 1940 event). Ministry of Public Works and

Communication, Bucharest 1941, 9p.; I - 1945 Instructions for preventing the damage of buildings due to earthquakes. Ministry of Public Works and Communication, Bucharest, 1945, 10p.; P13 - 63 and P13 - 70 Code for (structural) design of buildings in seismic zones. State Committee for Constructions, Architecture and Urban Planning, CSCAS, Bucharest, 1963, 39p. and 1970, 63p.; P100 - 78 and P100 - 81 Code for (structural) design of buildings in seismic zones. Central Institute for Research, Design and Management for Constructions ICCPDC,Bucharest, 1978, 57p. and 1981, 72p.; P100 - 90 and P100 - 92 Code for earthquake-resistant design of civil and industrial buildings. Ministry of Public Works and Land Planning, MLPAT, Bucharest, 1991, 152p. and 1992, 152p (English version 1993, 151p). Chapters 11, 12 were modified in 1996, 50p.

P100 – 2003 - Code for earthquake resistance of buildings and structure (Draft, 2003).

0.001

0.01

0.1

1

6.0 6.4 6.8 7.2 7.6 8.0

Moment magnitude, M w

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ulat

ive

num

ber,

n(>

M)

pery

r

log n (>M w ) = 3.76 - 0.73M w

20 th century Radu's catalogue

M w, max = 8.17.8

6.3 6.7 7.1 7.5 7.9 8.3

( ) )3.61.8(687.1

)1.8(687.1687.1654.8

11

−−

−−−

−

−=≥eeeMn

ww

MM

w

The accompanying standards for seismic zonation of Romania are:

STAS 2923-52 and STAS 2923-63, Macrozonation of the territory of R.S.Romania. State Office for Standardization, Bucharest, 1952 and 1963; Decree No. 66/1977 of the Romanian Government, 1977; STAS 11100/1-77, Macrozonation of the territory of R.S.Romania. Romanian Institute for Standardization, Bucharest, 1978; STAS 11100/1-91 and SR 11100/1-93, Macrozonation of the territory of Romania.Romanian Institute for Standardization, Bucharest, 1991 and 1994.

The contents of the seismic codes and of the standards for seismic zonation of territory of Romania can be classified in four generations of major developments described in Table 2.

Table 2. Classification of codes for design of earthquake resistance of buildings and

standards for seismic zonation of Romania (1940-2003)

Period Code for earthquake resistance of structures

Seismic zonation standard*

Pre-code, before 1963

Prior to the 1940 earthquake and

Prior to the 1963 code

P.I. - 1941 I - 1945

P.I. – 1941 I – 1945 STAS 2923 - 52

Low-code, 1963-1977

Inspired by the Russian seismic practice

P 13 - 63 P 13 - 70 STAS 2923 - 63

Moderate-code, 1977–1990

After the great 1977 earthquake

P 100 - 78 P 100 - 81 STAS 11100/1 - 77

Moderate-code to High-code,

after 1990

After the 1986 and the 1990 earthquakes

P 100 - 90 P 100 - 92

STAS 11100/1 - 91SR 11100/1 - 93

High code, after 2004 Inspired by Eurocode 8 P100 – 2003 (draft) -

*The intensity scale used in Romania is MSK - 64 scale (STAS 3684 - 63, STAS 3684 - 71)

0.0

1.0

2.0

3.0

0 1 2 3 4Period T , s

(T)

0.8/T0.9/T

3/T

0.750.6

7 yr.

12 yr.

6 yr.

6 yr.

after Aug.30, 1986P100-90P100-92

P100-78P100-81

P13-70

after March 4, 1977

ξ = 0.05P13-63

0.6

2.5

0.3 0.4 0.7 1.5

1.0

2.2 2.5

Figure 3. Normalised acceleration elastic response spectra in Romanian seismic codes, from the 1963 to 2002 (Lungu, 1996)

The evolution of normalized acceleration elastic response spectra in design provisions

for earthquake resistance of structures in Bucharest is given in Figure 3 and it is self-explanatory.

The evolution of seismic design coefficient for computing lateral force (shear) at the base of building structure in Bucharest is presented in Figure 4. One should note the gap of the

overall coefficient Cs for flexible buildings and structures built during the period 1963-1978; however, even for rigid structures built during that period, the maximum Cs was about 2/3 of the present Cs due to reduced MSK intensity (VII) recommended for Bucharest by STAS 2923-63 (Table3).

After the 1977 disaster, ductility rules for reinforced concrete structures were imported into Romanian codes from American Concrete Institute (ACI) codes of practice. Those ductility rules were improved in 1990 according to the EUROCODE 8 new requirements. Evolution of seismic zonation maps in Romania during the last 40 years is illustrated by Figure 4 and Table 3.

Figure 4. Evolution of seismic design coefficient in Bucharest during time interval 1940-2000, (Lungu, Demetriu, 1998)

Table 3. MSK seismic intensity in Bucharest Time interval Standard MSK intensity 1952 – 1963 STAS 2923-52 VIII 1963 – 1977 STAS 2923-63 VII 1978 – 1991 STAS 11100/1-77 VIII

1991 - present SR 11100/1-91 and 93 VIII

The present conversion of MSK intensity, adopted by Romanian standard SR 11100/1-93, into peak ground acceleration, ag used by Romanian code for design of earthquake resistance of structures, is given in Table 4.

0.10.4

0.7

1

1.3

1.6

1.9

0

2

4

6

8

10

12

Seismicdesign

coefficient Cs , %

8-10

6-8

4-6

2-4

Year of code issue

Building period T , s

10 %8%

12.5 %10%

5 %

2.2%1.8%2%

Shear wallsFrames

0.3 s

1.5 s

Tc=1.5 s

19411945

199019921978

19811970

1963

7.5%7.5% 7.2%

6.8%

Tc=0.4 s

RIGID buildings

FLEXIBLE buildings

Ductile structures Non-ductile buildings

Rigid buildings

Flexible buildings

Table 4 MSK-64 intensity in SR 11100/1-93 9 8 7 6 5ag /g in P100-92 code 0.32 0.25 and 0.20 (2 zones) 0.16 0.12 0.08

Figure 5. Evolution of seismic zonation of Romania (from 1963 to 1993 and 2002)

It is emphasized that the present seismic code of Romania, P100-92 defines the earthquake hazard by 50 yr. mean recurrence interval event (MRI=50yr i.e. 63% exceedance probability in 50 yr). However, since the American loading code ASCE 7-95, 2000 and EUROCODE 8 for earthquake resistance of structures define the design earthquake by 475 yr.

mean recurrence interval (MRI=475yr i.e. 10% exceedance probability in 50 years) event, the level of seismic hazard in present seismic code is now under revision. A comparison of the max. peak ground acceleration for design (MRI = 50yr. and MgRI = 475 yr.) in Bucharest, Skopje and other 8 cities around the world is presented in Figure 6.

Figure 6. Seismic hazard around the world – U.N. RADIUS Project,1999

The recorded maximum peak ground acceleration in Romania during in 1977, 1980 and 1990 Vrancea earthquakes in given in Figure 7.

Figure 9

Figure Figure 7.

Figure 7

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

0.0

Peak

Gro

und

Acc

eler

atio

nPG

A,g

Rome Bucharest Sofia Skopje Algiers Tehran Katmandu Salvador Santiago Bogota

Europe Africa Asia America

0.06

0.10

0.20

0.40

0.28

0.12 0.13

0.32

0.40

0.13

0.18

0.330.36

0.14

0.38

0.75

0.82

0.30 0.31

0.20

T = 50 yr

Mean recurrence intervalT = 475 yr

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ArcView GIS version 3.1, ESRI Inc. CA.

#· Epicenters of strong Vrancea events (Mw > 6.9)

Lungu, Aldea, 1999

N

EW

S

March 4, 1977

Mw=7.5h=109 km

Aug.30, 1986

May 30, 1990

Mw=7.2h=133 km

Mw=7.0h=91 km

Mw - moment magnitudeh - focus depth

200 - 300150 - 20075 - 1500 - 75

PGA, cm/s2

ROMANIA. Maximum peak ground acceleration PGA, cm/s2 recorded during 1977, 1986 and 1990 VRANCEA earthquakes

Seismic stations with free-field records:

& Bulgaria network

$ GEOTEC network&

# INCERC network% INFP network

R. of Moldova network

1.3 Draft P 100 2003 seismic code of Romania. Seismic hazard assessment

The present joint map of Vrancea seismic hazard of Romania, Bulgaria and Moldavia. Figure 8 and Tabel 5 still suggests a need for map improvement by joint regional efforts.

Figure 8. Seismic zonation maps for countries affected by Vrancea earthquakes

Table 5 for the map in Figure 8.

PGA/g

MSK Intensity ROMANIA P100-92&

SR 11100/1-93

Rep. of MOLDOVA, UKRAINE

SNIP II-7-81

BULGARIA 1987 code

IX 0.32 0.40 0.27

VIII 0.25 0.20 0.20 0.15

VII 0.16 0.10 0.10

V 0.12 0.08 - 0.05

Based on the results of probabilistic seismic hazard assessment for Vrancea source (Lungu et al., 1995...2002) and taking into account the contributions from the crustal seismic sources around Romania, Figure 8 presents the proposed hazard map for the new code for design of earthquake resistant buildings in Romania, P100-2003. The map give the design peak ground acceleration, ag for the MRI=100 yr seismic event.

Zaicenco, Lungu, 1999

Figure 9. Peak ground acceleration for design, ag for MRI=100 y., P100-2003 code proposal

The response spectra in Figure 9 is recommended for Romania and Bucharest locations characterized by various control period of response spectra: TC ≤0.7s, 0.7s <TC ≤1.0s, 1.0s<TC ≤ 1.6s during the MRI = 100 years Vrancea events.

Tξ

0.7s<Tc ≤ 1.0sξ =0.05

1.0s<ξ= 0

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3Perioada T , s

T B =0.07 T D =3

1.925/T

β 0 =2.75

T C =0.7s

2

2.5

3

3.5

2.75/T

β 0 =2.75

0

0.5

1

1.5

2

2.5

3

3.5

0 0.5 1 1.5 2 2.5 3Perioada T , s

TD =2

8

4.4/Tβ 0 =2.75

TB =0.16 T C=1.6s

Period T,s

Period T,s

c ≤ 0.7s =0.05

Tc ≤ 1.6s .05

3.5 4

5.775/T 2

0

0.5

1

1.5

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

T C=1.0sTB =0.1 T D=3

8.25/T 2

3.5 4

.8/T 2

Period T,s

Figure 10. Normalised acceleration design spectra for various soil condition in Romania, P100-2003 code proposal

There is an instrumental evidence, from both the 1977 earthquake and 1986 earthquake that soil condition in Bucharest is characterised by the long predominant period of ground vibration: Tg=1.4-1.6s. That Tg explains the long corner period of response spectra Tc=1.6s, in Figure10. A tentative macrozonation of Tc in Romania teritory is given in Figure 11.

Figure 8. Romania . Control period of response spectra, P100 - 2003

Figure 11. INCERC seismic station in Eastern Bucharest. Normalised power spectral density for the NS comp. of the Mar 4, 1977 and Aug 30, 1986 earthquakes

Figure 12. Romania. Control period of response spectra, P100-2003

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0 10 20 30 40Pulsatia ω, rad/s

Den

sita

tea

spec

trala

norm

aliz

ata 4 Martie 1977, M=7.2, comp.NS

30 Aug. 1986, M=7.0, comp. NS

ωp =2 π/T p

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Part II. Seismic Risk Management

2.1 The structure of the existing building stock in Bucharest

The structure of the existing building stock in Bucharest is given in Figure 12 and Table 6. The Bucharest population is about 2 million inhabitants. It is almost constant during the last 10 years.

Table 6. Inventory of existing housing units in Bucharest according to the periods of validity of various Romanian seismic codes.

Seismic code inter- benchmark periods

Housing units built during inter-benchmark periods

% housing units built during inter-benchmark periods

before 1941 168,556 21.95 ~22% 1941-1963 69,702 9.08 1963-1970 110,669 14.42 1970-1978 119,625 15.57 ~39% 1978-1992 292,594 38.09 1992-1995 6,844 0.89 ~ 39% Total 768,000 100%

0

500

1000

1500

2000

2500

Period of constructionN

umbe

rofb

uild

ings

Mid-rise buildings(3-7 storeys)

1900 1929 1945 1963 1970 1977 1990

Figure 13. Distribution of Bucharest buildings with period of construction

0

500

1000

1500

2000

2500

3000

Period of construction

Num

bero

fbui

ldin

gs

High-rise buildings(≥8 storeys)

1900 1929 1945 1963 1970 1977

0

5000

10000

15000

20000

25000

30000

35000

Period of construction

Num

bero

fbui

ldin

gs

Low-rise buildings(1-2 storeys)

1900 1929 1945 1963 1970 1977 1990

2.2 Fragile residential buildings in Bucharest

The List of the vulnerable buildings built in the center of Bucharest before 1940 and identified as having highest risk of collapse in the case of strong earthquake (comparable to 1977 event) contains 115 fragile mid-rise and high-rise buildings (March 2001/ Jan. 2003).

All those tall buildings listed as very vulnerable were located on the city map using the Geographic Information System (GIS) infrastructure, Figure 13 and Table 5.

In so called “Test area of central Bucharest” the GIS map (1:500) contains the location and detailed information on the more than 1700 buildings. All those buildings represented on map were digitised at Karlsruhe University within the technical cooperation between Technical University of Civil Engineering Bucharest (UTCB) and Karlsruhe University in the frame of German Science Foundation Project 461 devoted to Vrancea earthquakes.

The Test area in central Bucharest was selected by UTCB in 1997 based on location of the collapsed buildings during the 1977 earthquake in Bucharest.

Presently, the central Bucharest test area was extended to about 24000 buildings within European RISK-UE Project at University of Civil Engineering Bucharest, (UTCB) for including majority of the building listed as seismically vulnerable in Bucharest.

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Figure 14. Central Bucharest area with buildings built prior to 1945 and identified as having high risk of collapse in case of a strong earthquake (Mw≥7.5)

Table 7. Buildings with more than 5 stories built before 1940 located on the two most important boulevards of central Bucharest and identified as having highest risk of collapse in

case of strong (comparable to 1977) earthquake8

* Classification of damage in 1977 follows vulnerability classes of HAZUS methodology, 1998, (see Lungu, D., et al., 2000. Advanced Structural Analysis, Conspress, UTCB, 177p.);

No Address

Year of building

construction

Commercial occupancy of groundfloor

Storeys No. of Apt.

Total area sqm.

Damages after the 1977 earthquake in structural

elements

Repairing work after the 1977 earthquake

Gulkan Damage

score

1 Balcescu 24 (Pherekide) 1928 Yes 13 61 12197

Columns: Beams : Masonry:

Extreme Extreme Extreme

Jacketing of columns and beams

Masonry Repairs Epoxy resins injections

Mortar injections Finishes

100

4Calea Victoriei

101A-B

1937 Yes 11 61 6111Columns: Beams : Masonry:

Extreme Extreme

-

Jacketing of columns Masonry Repairs

Epoxy resins injections 86

6 Magheru 20 1935 Yes 10 52 5484Columns: Beams : Masonry:

-Light Light


Mortar injections 11

11 Magheru 27 1935 Yes 9.5 36 6405 Columns: Beams : Masonry:

Light --

Jacketing of columns 14

12 Calea Victoriei 2-4 1928 Yes 9 76 12994


Light Medium

-

Masonry Repairs 29

16 Calea Victoriei 128A 1935 Yes 9 22 6675




Masonry Repairs 100

20 Calea Victoriei 112 1939 Yes 9 27 5210



Jacketing of 4 columns Masonry Repairs

Epoxy resins injections

100

27 Calea Victoriei 208 1940 Yes 8.5 44 5200


Extreme Medium Extreme

Jacketing of beams Masonry Repairs

Epoxy resins injections 86



Light Light

Medium

Masonry Repairs 29

61 Balcescu 25 (Wilson) 1928 Yes 12 93 12287





Mortar injections Finishes

*partially collapsed in 1977

105



--

Light/ Medium

Masonry Repairs 37




Jacketing of 6 columns Epoxy resins injections

100





100

94 Balcescu 32-34 1935 Yes 10 41 6996

Columns:

Beams :

Masonry:

Light/ Medium Light/

Medium -

Masonry Repairs 42.5

95 Balcescu 30 1936 Yes 9.5 25 2756


Extreme -

Medium


Finishes 64

100 Balcescu 7 1933 Yes 7 15 2730


Light Light

Extreme


36

104 Calea Victoriei 33-35 1930 Yes 6.5 39 4800


Medium Medium Medium

Jacketing of columns Masonry Repairs

50

Balcescu 24(Pherekide) Calea Victoriei 101 A-B Magheru 20

Magheru 27 Calea Victoriei 2-4 Calea Victoriei 128A

Calea Victoriei 112 Calea Victorie 208 Calea Victoriei 139

Balcescu 25 (Wilson) Calea Victoriei 124 Calea Victoriei 25

Calea Victoriei 95 Balcescu 32-34 Balcescu 30

Balcescu 7 Calea Victoriei 33-35

Figure 15 Seismic vulnerability class 1

buildings on the most important two boulevards in

central Bucharest

The damage score for the fragile building structures from the list of 115 buildings in Bucharest was computed with a simplified version of the damage methodology proposed by Gulkan (1994), Middle East Technical University, Ankara, Turkey.

The calculation of damage score, SD for a building is based on the level of damage of the structural members at the most severely damaged story of the buildings (usually the groundfloor). The damage level of structural member is classified as follows:

No damage MD score = 0 Moderate damage MD score = 2 Light damage MD score = 1 Extreme damage MD score = 4.

The importance factor for structural elements, ω is selected as follows (Gulkan, 1994): Columns ω=2; Beams ω=1; Infill masonry ω=0.5.

The building structure damage score, SD can be computed as follows:

( ) ( ) ( )( ) ( ) ( )[ ] 100

4MDMDMD

SDillsinfbeamscolumns

illsinfbeamscolumns ⋅++

⋅+⋅+⋅=

ωωωωωω

SD varies from 0 to 100. The vulnerability classes can be selected based on SD score.

The simple criteria might confirm the hierarchy of actual vulnerability of the fragile buildings in Bucharest in the case of a strong earthquake:

(i) Presence of visible damage after the 1977 earthquake as well as the presence of visible local repairing made after that earthquake;

(ii) Presence of the soft ground floor due to commercial use of that floor (no infilled masonry walls);

(iii) Number of storeys of building (taller the building, higher the risk); (iv) Lack of vertical and horizontal symmetry of the building (setbacks,

asymmetrical architecture of the corner buildings) as well as unintended local structural damage due to occupancy changes and activities, corrosion of the reinforcement, low strength concrete (mean compressive strength 100-200 daN/cm2). etc. Table 5 and Figure 14 give the characteristics and the photos of 17 buildings seismic vulnerability class 1 located on the two most important boulevards of Bucharest. All of them were built before WWII (1940). Seismic "risk class” in present Romanian seismic code (P100-92) is actually seismic vulnerability class! That is why the seismic risk matrix presented in Table 8 should be used for the classification of actual seismic risk of vulnerable buildings in Romania.

Table 8. Seismic risk classes

Importance and exposure class Seismic Vulnerability/or

fragility class

IEssential facilities

II Hazardous buildings

III General buildings

IV Minor buildings

1 1 1 1&2 32 1&2 2 3 33 3

Recently (Dec 2002/Jan 2003), 42 pre-1977 buildings built during the time interval 1945- 1977 were included into the most dangerous seismic vulnerability class 1 buildings in Bucharest, Table 9 and Figure 16. They are tall RC buildings characterised by soft groundfloor located on soft soil condition of Bucharest city. Table 9. Fragile tall RC buildings having flexible groundfloor, built prior to 1977 earthquake in Bucharest

No. Name of street No. of buildings No. of stories Address of buildings

1

Calea Grivitei

18

B*+GF+ (7......12)S No. 3-5, 134, 139, 148, 156, 158, 163, 164, 169, 196, 198, 200, 206, 236, 238, 395, 398, 399

2 Stefan cel Mare 11 B+GF+ (6...8)S No. 5, 15. 17, 27, 28, 31, 33, 40, 42, 128, 188

3 Bd. Mihalache (1 Mai) 4 B+GF+(8...10)S No. 170, 172, 174, 399 4 Gara de Nord 3 B+GF+8S No. 2-4, 6-8, no.2 Piata 5 Dinicu Golescu Bd., 1 B+GF+9S No. 23-25 6 Piata Chibrit –C 1 B+GF+8S 7 Piata Amzei 1 B+GF+7S No. 12-22 8 Bd. N. Balcescu 1 B+GF+9S No. 33

9 Dorobanti/Stefan cel Mare corner 1 B+GF+12S Blocul Perla

10 Sos. Mihai Bravu, 1 B+GF+8S No. 107-119 * B – basement. GF – groundfloors, S - stories

Figure 16. Fragile tall RC buildings having flexible groundfloor, built prior to 1977 earthquake in Bucharest

Table10. List of cities with hospital buildings requiring strengthening work

Number of hospitals buildingsCitySeverely damaged.

Requiring immediatetechnical assessment

Having atechnical

report

Approvedproject forretrofitting

Retrofitting inwork

Bacau 3Bucharest 13 16 6 10Buzau 9Constanta 7Craiova 4Focsani 2Galati 6 2 1Giurgiu 1Iasi 21 17 2 5Pitesti 2 7Ploiesti 2Sibiu 1Targu-Mures

2

Vaslui 4 1Barlad 2

Churches damaged by major historical earthquakes in Bucharest Table 11

Level of damage No. Name Address 1802

event 1838 event

1940 event

1977 event

1 Manastirea Plumbuita, “de la Podul Colentinei”

Str. Plumbuita 58 severe

2 Manastirea Marcuta Str. Gentianei din Sos. Pantelimon severe

3 Doamnei (fosta manastire) Intr. Bis. Doamnei 3, Calea Victoriei 28 medium

4 Sf. Gheorghe-Nou Bd. Bratianu 27 medium

5 Manastirea Antim Str. Mitropolitul Antim Ivireanu 29 light

6 Sf. Elefterie-Vechi Str. Sf. Elefterie 15C medium medium

7 Oborul-Vechi Str. Traian 204 medium medium

8 Sf. Pantelimon Str. Iancu Capitanu 24 severe

9 Popa Rusu Str. Popa Rusu 13-17 medium

10 Precupetii Noi Str. G-ral Ernest Brosteanu 12 medium

11 Doamna Ghica-Tei Str. Doamna Ghica 2 medium

12 Manastirea Sf. Spiridon-Nou

Calea Serban Voda 29 medium

13 Sf, Nicolae Tabacu Calea Victoriei 180 medium medium

14 Sf. Nicolae-Selari Str. Blanari 16 / Intr. Selari collapse

15 Sf. Mina (Vergului) Str. C. F. Robescu 18A medium

16 Herastrau-Sfintii Apostoli Petru si Pavel

Str. Nicolae Caranfil 28 medium

17 Dobroteasa Bd. Mircea – Voda 35B medium

18 Amzei Str. Biserica Amzei 12 light medium

19 Biserica si Scoala Sf. Silvestru

Str. Silvestru 36 medium

20 Boteanu (cu Bradu) Str. Boteanu 8 medium severe

21 Popa Nan Str. Popa Nan 47 bis si Str. Gh. Costa-Foru 5 severe severe

22 Sfantul Apostol Andrei-Chitila II

Sos. Chitilei 138 severe

23 Aparatorii Patriei II Str. Lunca Barzesti 3 medium

Hospitals requiring technical assessment and retrofitting works (design, construction, financing) in various Romanian counties are listed in Figure 17 and Table 10. Various orthodox churches damaged by major historical earthquake in Bucharest are listed in Table 11 and in Figure18.

Figure 17

Figure 18

There is a certitude that, for about 50 years recurrence interval Vrancea earthquake, several dozens of pre-WWII tall RC buildings in Bucharest will collapse (there are about 60-100 pers/bldg). More than half of those buildings and several pre - 1977, framed RC structures in are already identified by licensed experts as “seismic risk class 1” buildings. The governmental action of identification of dangerous buildings in Romania started in 1994. In 2001, a new Government Order stated that the Government will 100% advance the necessary payment, for strengthening of the buildings, to the private owners of apartments in “seismic risk class 1” buildings (more than 95%of housing units are private in Romania!). If the owner salary is less then national average, he have to pay back(to the state) nothing. If it is not, he has to pay the money back in 25 years, with 5% interest. Anyway, the owner has to agree on the strengthening of its apartment, in case he has to leave the housing unit during the construction work. Of course, the owners do not like leaving and the necessity buildings for temporary housing during strengthening are not yet implemented. Moreover, if one apartment owner does not like/agree on strengthening of its apartment, the strengthening of the whole building can not be done!!! There is a promise of the Ministry of Public Works, during a May, 2003 Seminar, for promoting a new official act which will make compulsory the strengthening of the building structure if the majority of private owners will accept the strengthening(in spite of several owners who would not like to allow strengthening of their apartments). Distribution per counties of residential buildings, hospital buildings and school buildings, requiring strengthening/retrofitting works in Romania is presented in Figure 19. Present stage of construction work of the first 8 buildings under retrofitting/strengthening in Bucharest is given in Table 12. Table 12.

Building 1 2 3 4 5 6 7 8

Total area (sqm) 6050 1831 1615 1750 12313 2013 3706 2271

Height B+GF+8S B+GF+6S B+GF+6S B+GF+6S B+GF+11S B+GF+5S B+GF+8S B+GF+5S

1 ) Present stage of retrofitting work, 20÷70%; 2) Cost of structure strengthening 50 - 150€/ sqm, 3) Duration of construction, 8÷12 month

Figure 19

Seismic instrumentation of Romania and Bucharest

Based on deep recognizance of the extraordinary importance of seismic records for understanding of the strong motion characteristics, Romania installed in the last 2 years about 50 digital K2 and ETNA, Kinemetrics instruments.

The present seismic instrumentation of Romania is summarized in Table 13 and in the maps in Figure 20.

Table 13. Seismic networks of Romania, 2003 Name of network Bucharest Romania

(including Bucharest) INCERC & ISC, State Inspectorate for Construction

7 ETNA 31 ETNA

New digital networks, installed in 2003 CNRRS & JICA, Japan

International Cooperation Agency Project1

11 K2 16 instruments: -11 K2; - 5 ETNA

INCERC

21 instruments: -10 SMA-1 (analog) -9 ADS (digital) -2 digital stations for continuous monitoring

70 instruments: -58 SMA-1(analog) -9 ADS (digital) 3 digital station for continuous monitoring Existing seismic

networks, in 2002 INFP/SFB 461 German Science Foundation Project at University of Karlsruhe

15 K2 41 K2

TOTAL 54 digital instruments 158 instruments 100 digital 1) UTCB & INCERC are partner institutions with CNRRS.

Figure 20

The table indicates 100 Kinemetrics digital instruments in Romania, 54 in Bucharest, as well as more than 100 instruments in INCERC seismic network, (45 digital) and 41 Kinemetrics digital instruments in the joint seismic network of SFB 461- Project on Vrancea earthquakes at Karlsruhe University, and INFP, National Institute for Earth Physics, Bucharest.

The Japan-Romanian Project on Seismic Risk Reduction in Romania, implemented by JICA & CNRRS in partnership with UTCB & INCERC, installed in 2003 16 instruments in Romania i.e.:

(i) 7 K2 stations at 7 locations in Bucharest, each with 3 sensors: 1 free field and 2 in deep boreholes (-30.0 m ÷ -180.0 m);

(ii) 5 ETNA accelerometers outside Bucharest; (iii) 4 K2 station in four significant buildings in Bucharest. In addition to the Romanian-Japanese and Romanian-German seismic cooperation

projects, State Inspectorate for Construction of Romania provided 31 ETNA Kinemetrics digital instruments, which are operated by INCERC in partnership with ISC (10 instruments, still to be installed).

ACKNOWLEDGEMENT

We would like acknowledge our deep gratitude to:

- ISC, State Inspectorate for Construction, Romania;- JICA, Japan International Cooperation Agency and - UTCB, Technical University for Civil Engineering Bucharest and CNRRS,

National Centre for Seismic Risk Reduction joint instrumentation team, - INCERC seismic network laboratory, - SFB 461- Project on Vrancea Earthquake at Karlsruhe University

for their sustained efforts during years to complete the present stage of digital seismic instrumentation of Romania and Bucharest.

REFERENCES

ASCE 7-98, 2000. ASCE Standard: Minimum design loads for buildings and other structures. American Society of Civil Engineers, New-York, ASCE, SEI

Bolt B., (1995), Earthquakes, W.H. Freeman and Company, New York, 331 p. Coburn, A., Spence, R., (1992), Earthquake protection, John Wiley & Sons., New York, 355p. Constantinescu, L, Marza, V., (1980), A computer-compiled and computer-oriented catalogue of Romania’s

earthquakes during a millenium (984-1979), Géophysique, Tome 24, No2, Bucharest, p.193-206. Elnashai A., Lungu D., 1995. Zonation as a tool for retrofit and design of new facilities. Report of the Session

A.1.2. 5th International Conference on Seismic Zonation, Nice, France, Oct. 16-19, Proceedings Vol.3, Ouest Editions, Preses Academiques, p.2057-2082.

Eurocode 8 - Design provisions for earthquake resistance of structures, 1994. Part 1-1: General rules - Seismic actions and general requirements for structures. CEN, European Committee for Standardization, Oct.

Hwang H.H.M., Huo J.R., 1994. Generation of hazard-consistent fragility curves for seismic loss estimation studies. Technical Report NCEER-94-0015. National Center for Earthquake Engineering Research, State University of New York at Buffalo, Aug.

Lungu D., Aldea A., Arion, C., Demetriu S.,Cornea T., 2000. Microzonage Sismique de la ville de Bucarest - Roumanie, Cahier Technique de l’Association Française du Génie Parasismique, No.20, p.31-63

Lungu, D., Vacareanu, R., Aldea, A., Arion, C., 2000. Advanced Structural Analysis, Conspress, UTCB, 177p. Lungu, D., Arion, C., Baur, M., Aldea, A., 2000. Vulnerability of existing building stock in Bucharest, 6ICSZ Sixth

International Conference on Seismic Zonation, Palm Springs, California, USA, Nov.12-15, p.837-846 Lungu, D., Aldea, A., Arion, C., 2000. "Engineering, state & insurance efforts for reduction of seismic risk in

Romania" In: Proceedings of the 12th World Conference on Earthquake Engineering, Auckland, New Zealand, Jan/Feb.

Lungu D., 1999. Seismic hazard and countermeasures in Bucharest-Romania, Bulletin of the International Institute of Seismology and Earthquake Engineering IISEE, Tsukuba, Japan, Vol.33, p.341- 373.

Lungu, D. & Aldea, A., 1999. Understanding Urban Risk Around the World. United Nations RADIUS Project at Geohazards Int., Ca., USA. Document City of Bucharest Seismic Profile, 29p.+25p.+8p.

Lungu, D., Arion, C., Aldea, A., Demetriu, S., 1999, “Assessment of seismic hazard in Romania based on 25 years of strong ground motion instrumentation”, NATO ARW Conference on strong motion instrumentation for civil engineering structures, Istanbul, Turkey, June 2-5, 1999.

Lungu, D., Aldea, A., Arion, C., Cornea, T., 1998. "Seismic hazard zonation in Eastern Europe", Second International Conference on Earthquake Hazard and Seismic Risk Reduction, September 15-21, Yerevan, Armenia , Kluwer Academic Publisher, 2000, p281-289.

Lungu, D., Demetriu, S., Arion, C. 1998. Seismic vulnerability of buildings exposed to Vrancea earthquakes in Romania. In Vrancea Earthquakes. Tectonics, Hazard and Risk Mitigation, Kluwer Academic Publishers, Wenzel F., Lungu D., editors, Proc. of First International Workshop on Vrancea Earthquakes, p.215-224.

Lungu D., Cornea T., Nedelcu C., 1998. Probabilistic hazard assessment and site-dependent response for Vrancea earthquakes. In Vrancea Earthquakes. Tectonics, Hazard and Risk Mitigation, Kluwer Academic publishers b.v., Wenzel F., Lungu D., editors, p.251-268

Marza, V.I., Kijko, A., Mäntyniemi, P., (1991), Estimate of earthquake hazard in the Vrancea (Romania) region,Pageoph, Vol.136, No.1, Birkhäuser Verlag, Basel, p.143-154.

Munich Re, 1998. World Map of Natural Hazards Radu C. manuscripts, 1994. Catalogues of earthquakes occurred on Romanian territory during the periods 984-

1990 and 1901-1994. Zanfir A., 2000. Assessment of damage buildings (Master thesis, in Romanian), UTCB, 75p. Wells D.L., Coppersmith K.J., 1994. New empirical relations among magnitude, rupture length, rupture width,

rupture area, and surface displacement. Bulletin of the Seismological Society of America, Vol.84, No 4,p. 974-1002.

Cornea T., Vacareanu R. and Lungu D., 2000 Technical Report for Collaborative Research Center (CRC) 461 of SFB, Germany: “Strong Earthquakes: A Challenge for Geosciences and Civil Engineering”, Karlsruhe University, 64 p.

HAZUS – Technical Manual 1997. Earthquake Loss Estimation Methodology, 3 Vol. Newmark, N. M., and Hall, W. J. (1982). Earthquake Spectra and Design. Berkeley, Calif. Earthquake

Engineering Research Inst. Văcăreanu R., Cornea T., Lungu D. Evaluation of seismic fragility of buildings, Earthquake Hazard and

Countermeasures for Existing Fragile Buildings, Editors: Lungu D. & Saito T., Independent Film, Bucharest Romania.

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