Download Housing Stock

Redução da vulnerabilidade e
mitigação do risco sísmico.
Aplicação à Área
Metropolitana de Lisboa
Alfredo Campos Costa
e
Maria Luísa Sousa
Workshop projecto LESSLOSS – SP10 –
Earthquake disaster scenario prediction and loss modelling for urban areas
Curso de formação em modelação de perdas em consequência de sismos,
técnicas para a redução da vulnerabilidade e risco sísmico
LNEC, 25 de Maio de 2006
Index
1. Choice of case study area
2. Vulnerability and inventory definition
3. Loss modelling for the Metropolitan
Area of Lisbon - MAL
3.1 Reference situation
3.2 After mitigation
4. Conclusions
Index
1. Choice of case study area
2. Vulnerability and inventory definition
3. Loss modelling for the Metropolitan
Area of Lisbon - MAL
3.1 Reference situation
3.2 After mitigation
4. Conclusions
Choice of case study area
• Metropolitan Area of Lisbon - MAL
1755 eq
M8.75
1909 eq
M  6.9
3 x 106
inhabitants
Choice of case study area
• Metropolitan Area of Lisbon - MAL
96 km
MAL
90 km
Global Statistics 2001
Parishes
277 (7%)
Geotechnical profiles
37
Number of smallest geographic
divisions:
parishes+ geotechnical profiles
405
Building classes
49
Residential buildings
477 170 (16%)
Dwellings
1 389 236 (29%)
Population
2 841 067 (29%)
2001 GDP
 55106 € ( 47%)
Choice of mitigation options
• MAL
 Main causes of losses
• Human losses: severe and complete damage in most
masonry buildings
• Economic losses: damages on RC buildings with the
highest exposure in the region (>1960)
 Mitigation actions
• Upgrading most masonry buildings
• Upgrading of RC buildings >1960 mainly those located in
soils correspondent of the higher exposure of buildings
 Methodology
• Develop new capacity and fragility curves; consider a
possible range of modification techniques.
• update LNECloss tool
Index
1. Choice of case study area
2. Vulnerability and inventory definition
3. Loss modelling for the Metropolitan
Area of Lisbon - MAL
3.1 Reference situation
3.2 After mitigation
4. Conclusions
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Traditional
construction
(rural)
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
Before 1755
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
“Pombalinos”
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
“Gaioleiros”
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
Unreinforced
brick with RC
floors “Placa”
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
Confined masonry
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Without ERD
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
After RSCCS code
and before RSA
code
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
After RSA code
Vulnerability and inventory definition
• Characterization of MAL housing stock
Housing Stock
Masonry old buildings
and traditional
construction
Masonry old
buildings
(urban)
Buildings after arrival
of RC
Masonry with RC
floors
RC
Vulnerability and inventory definition
• Geographic distribution of exposure
#Buildings/km^2
0 - 50
50 - 100
100 - 250
250 - 500
500 - 1000
1000 - 2000
2000 - 5827
#Inhabitants/km^2
0 - 100
100 - 500
500 - 1000
1000 - 5000
5000 - 10000
10000 - 20000
20000 - 34077
Lisbon
N
10
0
10 Kilometers
MAL
Vulnerability and inventory definition
• 7 vulnerability classes x 7 nº floors
Vulnerability classes
315
Adobe + rubble stone + others
Masonry before 1960
Masonry 1961-85
49
Masonry 1986-01
RC before 1960
RC 1961-85
RC 1986-01
7
Vulnerability and inventory definition
• Vulnerability characterization
Spectral acc. Sa [g]
200
0,24
0,18
175
No damage
Slight
150
0,12
Moderate
Extensive
0,06
125
Complete
P[ D >= d | Sd , V ] [%]
/0
100
100
75
50
25
0
0
1
2
3
4
Spectral displacement Sd [cm]
5
6
49 typologies
Vulnerability and inventory definition
• Soil classification
Ground
type
Stratigraphic profile
vs [m/s]
A
Rock and hard soil
> 350
B
Intermediate soil
200-350
C
Soft soil
< 200
37
So il cla sses
Hard soil
Inte rm. soil
So ft so il
N
3
10
0
10 Kilo me ters
MAL
Vulnerability and inventory definition
• Exposure analysis
Total of dwellings: 1 389 236
250 000
RC 1986-01
200 000
RC 1961-85
150 000
RC <= 1960
100 000
Masonry 1986-01
Masonry 1961-85
50 000
Masonry<=1960
Adobe and rubble stone
Soft soil
Interm. Soil
0
Hard soil
Nº of dwellings
300 000
MAL
Vulnerability and inventory definition
• Exposure analysis
Total of ihnabitants: 2 841 067
600 000
RC 1986-01
500 000
RC 1961-85
400 000
RC <= 1960
300 000
Masonry 1986-01
200 000
Masonry 1961-85
100 000
Masonry<=1960
Adobe and rubble stone
Soft soil
Interm. Soil
0
Hard soil
Nº of inhabitants
700 000
MAL
Vulnerability and inventory definition
• Exposure analysis
Total area: 237 676 665 m 2
45E+6
40E+6
35E+6
RC 1986-01
RC 1961-85
30E+6
25E+6
20E+6
15E+6
10E+6
5E+6
000E+0
RC <= 1960
Masonry 1986-01
Masonry 1961-85
Adobe and rubble stone
Soft soil
Interm. Soil
Masonry<=1960
Hard soil
Total area [m 2 ]
50E+6
MAL
Index
1. Choice of case study area
2. Vulnerability and inventory definition
3. Loss modelling for the Metropolitan
Area of Lisbon - MAL
3.1 Reference situation
3.2 After mitigation
4. Conclusions
Loss Modelling for MAL
• Modelling earthquake ground motion
11°
Surface
9°
42°
7°
42°
N
North
site


OS
Ú
Ê
Ê
Ú
40°
R
Ú
Ê
W
L
3
2 Ú
ÚÊ
Ê
9
1
Ú8 Ê
Ê
Ú
4
Mag nitud e
Ú 3.3
Ê
38°
Ú 3.4
Ê
Ú 3.6
Ê
Ú 3.9
Ê
Ú 4.0
Ê
Ú 4.1
Ê
Ú 4.2
Ê
Ú 4.4
Ê
36°
Ú 4.5
Ê
Ú 5.4
Ê
Ú 5.8
Ê
Ú
Ê
11 12
38°
7
Ú
ÊÊ
Ú
Ú Ê
36°
6
Ú
Ê
11°
Aceleração
[cm/s^2]
SA [cm/s^2]
x
y
r
O 
(x,y)
z
Ê 10
Ú
5
h
40°
9°
180
160
7°
Mo, To
140
120
100
log SA = c1 +c2 M + c3 log Rhipo + c4 Rhipo
80
60
40
20
0
0
200
400
Rhipo [km]
600
800
Loss Modelling for MAL
• Modelling earthquake scenario
 Earthquake scenario  modal values
derived from PSHA disaggregation
475 years RP
50 years RP
50 Y
200000
100000
0
0
#
475 Y
0
100000
200000
Contrib. [‰]
#
m
Contrib. [‰]
300000
300000 m
( y  x z)
( x y  z)
RP [years]
M
X [km]
Y [km]
50
4.4
146.5
213.6
475
7.9
67.3
-4.4
Site effects
• Soil dynamic amplification
Sa [g]
1.2
1
0.8
0.6
0.4
0.2
0
0
5
10
15
20 Sd [cm] 25
Loss Modelling for MAL
• Modelling earthquake scenario
475 years RP scenario
PGA [cm/s^2]
40 - 100
100 - 130
130 - 160
160 - 190
190 - 220
220 - 250
250 - 280
280 - 310
310 - 340
> 340
Tagus
N
River
10
PGA for bedrock
0
10 Kilometers
PGA considering
soil columns
Loss Modelling for MAL
• Modelling Building vuln. and damage evaluation
 Capacity curve
 Yield capacity (Dy, Ay)
Ay = Cs  / 
Dy = Ay Te2 / (2)2
 Ultimate capacity
Au =  Ay
 Fragility curve
 Drift ratio d
Du =   Dy
 1  Sd
PD D  d Sd     ln 
  d  Sd d
Sd d   d   2  h




Mechanic model
• Capacity spectrum method
Spectral acceleration SA
Iteration 0: Te
x0 initial
response spectra
x1
x2
Iteration 1: T1
Iteration 2: T2
Capacity curve
Tf
Performance point
(SD max , SA max )
xf final demand
spectra after
convergence
Tf >T2>T1>Te
Spectral displacement SD
Loss Modelling for MAL
• Modelling Building vuln. and damage evaluation
Spectral acc. Sa [g]
200
0,24
0,18
175
No damage
Slight
150
0,12
Moderate
Extensive
0,06
125
Complete
P[ D >= d | Sd , V ] [%]
/0
100
100
75
50
25
0
0
1
2
3
4
Spectral displacement Sd [cm]
5
6
49 typologies
Loss Modelling for MAL
• Modelling strengthening interventions
Criteria derived from losses for the
reference situation and 475 RP
Ground
type
Adobe +
rubble
stone
Masonry
 1960
Masonry
1961-85
Hard



Interm.



Soft

Masonry
1986-01

RC
 1960
RC
1961-85
RC
1986-01




Loss Modelling for MAL
• Modelling strengthening interventions
# Streng.
Masonry
RC
Improvement of force
capacity
Improvement of ductile
capacity.


d
1




-
25%
25%
2


-
50%
25%
3


-
75%
25%
4


75%
75%
25%
5


-
25%
50%
6


-
50%
50%
7


-
75%
50%
8



75%
75%
50%
9

-
25%
75%
10

-
50%
75%
11

-
75%
75%
12


75%
75%
75%
Loss Modelling for MAL
• Modelling strengthening interventions
Ref. Masonry
M#1
M#2
M#3
M#4
slight
moderate
extensive
complete
Sa Reinforced / Sa Reference [%]
306%
200%
175%
150%
125%
100%
0
3
6
Spectral displacement [cm]
9
12
Loss Modelling for MAL
• Loss estimates for modified city
 Buildings (Masonry + RC) Completely damaged
for the reference situation and for the 12
intervention strategies
4
Ref. Masonry
Total of buildings = 477 170
Ref. RC
% of buildings completely damaged
Masonry
RC
3
2
1
0
Ref.
Str.#1 Str.#2 Str.#3 Str.#4 Str.#5 Str.#6 Str.#7 Str.#8 Str.#9 Str.#10 Str.#11 Str.#12
Loss Modelling for MAL
• Loss estimates for modified city
 Population killed (inhabitants of Masonry and RC
buildings) for the reference situation and for the
12 intervention strategies
0.09
Total of inhabitants = 2 841 067
0.08
Ref. Masonry
Ref. RC
Masonry
‰ of population killed (night)
0.07
RC
0.06
0.05
0.04
0.03
0.02
0.01
0.00
Ref.
Str.#1 Str.#2 Str.#3 Str.#4 Str.#5 Str.#6 Str.#7 Str.#8 Str.#9 Str.#10 Str.#11Str.#12
Loss Modelling for MAL
• Loss estimates for modified city
 Modified urban region (Str.#8 for masonry and
Str. #12 for RC)
N
Mitigation
Reference
N
Dam age
[% ]
0
0-1
Dam age [% ]
1-2
0
02- -1 3
1-2
3-4
2-3
34- -4 5
45- -5 10
5 - 10
10 - 1 5
10 - 1 5
15- 2- 02 0
15
20
20- 2- 52 5
25 - 2 8
25 - 2 8
10 0 10 Kilometers
10
0
10 Kilometers
Severely damaged buildings
Loss Modelling for MAL
• Loss estimates for existing city
Lost area for damage state d * DRd [m 2*10 6]
 Disaggregation of economic losses, by damage
state, for the 475 return period scenario
7
6
Masonry
RC
5
4
3
2
1
0
Slight
Moderate
Severe
Damage state
Complete
Loss Modelling for MAL
• Loss estimates for modified city
 Modified urban region (Str.#8 for masonry and
Str. #12 for RC)
N
Mitigation
Reference
DamNage [% ]
0
0-1
- ]2
Dam age1 [%
0
2-3
0-1
13
- 2- 4
24
- 3- 5
3-4
5 - 10
4-5
5 10
- 10 - 1 5
10 - 1 5
15 - 2 0
15 - 2 0
2020
- 2 -5 2 5
2525
- 2 -8 2 8
10
10
0
0
10 Kilometers
10 Kilometers
Completely damaged buildings
Loss Modelling for MAL
• Loss estimates for modified city
 Modified urban region (Str.#8 for masonry and
Str. #12 for RC)
Mitigation
Reference
D eat hs [#]
0
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
5 - 6
D eat hs [#]
0
0 - 1
1 - 2
2 - 3
3 - 4
4 - 5
5 - 6
N
10
0
N
10
0
10 Kilo me ters
10 Kilo
me ters
kilometers
Killed population
Loss modelling for MAL
Loss
scenarios
Loss
modelling
Probabilistic
Seismic Risk
Analysis
Loss Modelling for MAL
• Modelling earthquake scenario
 Earthquake scenario based on PSHA
disaggregation
RP [years]
M
X [km]
Y [km]
50
4.4
146.5
213.6
95
7.2
67.3
-4.4
475
7.9
67.3
-4.4
975
8.2
67.3
-4.4
5000
8.5
67.3
-4.4
Loss Modelling for MAL
• Loss estimates for modified city
Economic mitigation risk curves
Mitigation = E(Lref|h) –E(Lmitig|h)
20
Str.#8
20000
Str.#12
15000
10
10000
5
5000
1000
0
10
100
1000
Return period [year]
10000
Mitigation [x10 6€]
Mitigation / GDP [%]
15
Loss Modelling for MAL
• Loss estimates for modified city
 Human mitigation risk curves
Mitigation = E(Lref|h) –E(L mitig|h)
0.4
Str.#8
700
0.2
500
400
0.1
200
100
0
10
100
1000
Return period [year]
10000
Human Mitigation [#]
Mitigation / Population [‰]
Str.#12
0.3
Loss Modelling for MAL
• Loss estimates for modified city
 Average economic mitigation for an exposure
period of 50 years
E(L)= E(L|H)f(h)dh
H
Loss Modelling for MAL
• Loss estimates for modified city
 Average human mitigation for an exposure period
of 50 years
E(L)= E(L|H)f(h)dh
H
Index
1. Choice of case study area
2. Vulnerability and inventory definition
3. Loss modelling for the Metropolitan
Area of Lisbon - MAL
3.1 Reference situation
3.2 After mitigation
4. Conclusions
Conclusions
• MAL case study
Target area
Number of buildings
Approx. Population
Metropolitan Area of Lisbon
477,170
3,000,000
Approx. return period
500
Magnitude
7.9
Location of earthquake
Depth
Distance from target area
Range of macroseismic intensity
in the target area
Marques of Pombal Thrust Fault
 10 km
(Offshore)
VII-IX
(MMI)
Conclusions
• Proposed Mitigation Action
 Improve ductile capacity and force capacity
for most masonry buildings and for RC
buildings constructed after 1st seismic code
Conclusions
• Losses are a consequence of:
1.
Some masonry classes being high vulnerable
(e.g. Adobe + rubble stone) cause significant
human losses
2.
Less severe physical damages plays an
important relative contribution to economic
losses, mainly in RC buildings
Conclusions
• Risk mitigation for earthquake in MAL
Target area
Proposed Mitigation Action
Metropolitan Area of Lisbon
Improve ductile capacity and force capacity
for most masonry buildings and for RC
buildings constructed after seismic code
% of buildings Severely damaged
10.1%
% of buildings Severely damaged
WITH mitigation
3.5% - 7.3%
% of buildings Completely
damaged
3.9%
% of buildings Completely
damaged WITH mitigation
0.8% - 2.4%
No. and % of population killed
(night)
No. and % of population killed
WITH mitigation
269 (0.0095%)
79 (0.0028%) – 166 (0.0058%)
Conclusions
• Impact of the purposed mitigation actions
Benefits = [E(Lref|h) –E(Lmitig|h)]/ E(Lref|h)
Impact
indicator
Buildings
Severely
damaged
Buildings
Completely
damaged
Population
killed
Before
mitigation
After
Mitigation
Mitigation
benefits
48 580
(10.1%*)
16 901
(3.5%)
till
34 866
(7.3%)
28%
till
65%
18 660
(3.9%)
4 032 (0.8%)
till
11 489
(2.4%)
38%
till
78%
269
(0.0095%)
79 (0.0028%)
till
166
(0.0058%)
38%
till
71%
*The numbers indicated in brackets represent the percentage of losses relatively to total MAL buildings