multi-criteria decision analysis in seismic nicola caterino · 2006. 9. 21. · nicola caterino...

One-Day Research ShowcaseNovember 14th 2006

MultiMulti--Criteria Decision Analysis in Seismic Criteria Decision Analysis in Seismic Retrofitting ProjectsRetrofitting Projects

Nicola Caterino

Universitàdi Napoli

Federico II

Nicola CaterinoNicola CaterinoMultiMulti--Criteria Decision Analysis in Seismic Retrofitting ProjectsCriteria Decision Analysis in Seismic Retrofitting Projects

Complex problem

e.g. economic problems (marketing, resources allocation), natural and environmental resources management (plant location, disposal of dangerous waste), medical choices (optimal therapy strategy for a patient), etc.

Several solutionsSeveral objectives

MULTIMULTI--CRITERIA DECISION MAKING (MCDM)CRITERIA DECISION MAKING (MCDM)

SEISMIC RETROFIT OF EXISTING BUILDINGS: USE OF MCDMSEISMIC RETROFIT OF EXISTING BUILDINGS: USE OF MCDMSeismic Capacity ≥ Seismic

demand

Several feasible interventions

Many judgement criteria

Conflicting criteria

Best retrofit alternativeBest retrofit alternativeMCDM

Best solutionBest solutionMCDM


DECISION MAKING PROCEDURE FOR SEISMIC DECISION MAKING PROCEDURE FOR SEISMIC RETROFIT OF A BUILDINGRETROFIT OF A BUILDING

2.2. SET OF ALTERNATIVES DEFINITION

4.4. CRITERIA SELECTION

5.5. CRITERIA “WEIGHTS”

7.7. MCDM (TOPSIS) METHOD APPLICATION: BEST ALTERNATIVE

1.1. BUILDING ASSESSMENT

STEPSSTEPS

6.6. EVALUATION OF SOLUTIONS

3.3. RETROFIT INTERVENTIONS DESIGN


3 storeys

Smooth bars

Designed for gravity loads only

Largely spaced stirrups

Irregular in plan

CASE STUDY: GRAVITY ONLY DESIGNED RC BUILDINGCASE STUDY: GRAVITY ONLY DESIGNED RC BUILDING


Demand > Capacity !

(a) GFRP confinement

(c) Concrete jacketing of columns(b) Steel bracing

Strategy selection

Retrofit system

CAPACITY IMPROVEMENTCAPACITY IMPROVEMENT DEMAND REDUCTIONDEMAND REDUCTION

Base isolation

Seismic retrofit

selection

0

0,3

0,6

0,9

0 1 2 3 4T(s)Sa

(g)

x =5%

x=10%

SET OF ALTERNATIVE INTERVENTIONSSET OF ALTERNATIVE INTERVENTIONS

Originalstate

Stre

ngth

Ductility

(b)

(c)

(a)

Requiredseismicperformance

UNSAFEREGION

REGIONSAFE


0

200

400

600

800

1000

1200

1400

1600

0 1 2 3 4 5 6 7 8 9 10 11 12 13

Roof displacement (cm)

Bas

e sh

ear (

kN)

Original stateGFRPConcrete jacketingSteel bracing

Original stateGFRPConcrete jacketingSteel bracing

As built structure / GFRP (A1) / Steel bracing (A2) / Concrete jacketing (A3):pushover curves comparison

Originalstate

Stre

ngth

Ductility

(b)

(c)

(a)

Requiredseismicperformance

UNSAFEREGION

REGIONSAFE


C8 (14.1%)

C7 (3.5%)

C6 (20.1%)

C5 (2.6%)C4 (28%)

C3 (7.3%)

C2 (17.2%)

C1 (7.3%)

SOCIAL / ECONOMICAL CRITERIA TECHNICAL CRITERIA

C1: Installation cost

C2: Maintenance cost

C3: Duration of works / disruption of use

C4: Functional compatibility

C5: Skilled labour requirement / needed technology level

C6: Size of the needed intervention at foundation

C7: Significant Damage riskC8: Limited Damage risk

SELECTION OF THE EVALUATION CRITERIASELECTION OF THE EVALUATION CRITERIA

DEFINITION OF THE CRITERIA WEIGHTSDEFINITION OF THE CRITERIA WEIGHTSWeight wwii of criterion Ci (i=1,2,…,8) measures its relative importance (%)relative importance (%) to the final decision.


CC11 CC22 CC33 CC44 CC55 CC66 CC77 CC88

AA11 23 096 23 206

115 037 - -

AA33 11 174 40 353 34 - - 2.97 0.040 0.172

--97 884

33 - - 2.90 0.022 0.311

AA22 53 979 122 15.18 0.024 0.002

AA44 74 675 119 2.65 0.020 0.000

(€)

EVALUATION OF ALL ALTERNATIVESEVALUATION OF ALL ALTERNATIVESIN RESPECT OF ALL CRITERIAIN RESPECT OF ALL CRITERIA

Install.cost

Mainten.cost

Works’duration

Functionalcompatib.

Skilledlabour

requirem.

Sizeinterventionfoundation

S.D. risk

D.L. risk

GFRP

STEEL

R.C

BASE

(days)(€) (qualitative) (qualitative)

Conversion of qualitative evaluations into quantitative variables

BRACING

JACKETS

ISOLATION



AA11 23 096 23 206

115 037

AA33 11 174 40 353 34 2.97 0.040 0.172

97 884

33 2.90 0.022 0.311

AA22 53 979 122 15.18 0.024 0.002

AA44 74 675 119 2.65 0.020 0.000

(€)

EVALUATION OF ALL ALTERNATIVESEVALUATION OF ALL ALTERNATIVESIN RESPECT OF ALL CRITERIAIN RESPECT OF ALL CRITERIA

Install.cost

Mainten.cost

Works’duration

Functionalcompatib.

Skilledlabour

requirem.

Sizeinterventionfoundation

S.D. risk

D.L. risk

(days)(€) (qualitative) (qualitative)

DECISION MATRIXDECISION MATRIX DD=[=[xxijij]]

0.5380.538 0.4140.414

0.0740.074 0.1200.120

0.2740.274 0.0520.052

0.4140.4140.1140.114

GFRP

BRACING

JACKETS

STEEL

R.C

BASEISOLATION


…normalized… …weighted…

“IDEAL” SOLUTION

RR=[=[rrijij]]

“NEGATIVE” SOLUTION


AA44 0,057 0,107 0,049 0,052 0,018 0,033 0,013 0,000

AA11 0,018 0,025 0,014 0,243 0,018 0,037 0,014 0,123

AA22 0,041 0,125 0,050 0,033 0,005 0,191 0,015 0,001

AA33 0,009 0,044 0,014 0,124 0,002 0,037 0,025 0,068

VV=[v=[vijij]=[]=[wwjjrrijij]]Decision matrix DD=[=[xxijij]]

A*A* [0,009 0,025 0,014 0,243 0,002 0,033 0,013 0,000]

AA-- [0,057 0,125 0,050 0,033 0,018 0,191 0,025 0,123]

SELECTION OF THE SELECTION OF THE BEST ALTERNATIVEBEST ALTERNATIVEMCDM METHOD APPLICATION: MCDM METHOD APPLICATION: TOPSISTOPSIS (Yoon(Yoon--Hwang 1980)Hwang 1980)

GFRPSTEEL BRACING

R.C. JACKETSBASE ISOLATION


−

−

+=

ii

ii SS

SC*

* 4,3,2,1=i

CC88CC66

CC44

AA11 (GFRP(GFRP))

AA22 (BRACING)(BRACING)

AA33 (RC jackets)(RC jackets)

AA44 (ISOL.)(ISOL.)

AA**

AA--SSii

--

Si*

The best solutionbest solution, having the minimum

relative distance from ideal solution A*, has

the maximum value of the ratio Ci*

Si- : distance of alternative Ai from A-

(compatibility)

(intervention at foundation)(LD risk)

MCDM METHOD APPLICATION: MCDM METHOD APPLICATION: TOPSISTOPSIS (Yoon(Yoon--Hwang 1980)Hwang 1980)SELECTION OF THE SELECTION OF THE BEST ALTERNATIVEBEST ALTERNATIVE

Si* : distance of alternative Ai from A*


SSi*i* SSii-- CCi*i*

AA11 0.125 0.285

0.125

AA33 0.139 0.213 0.600.60

0.202

0.700.70

AA22 0.285 0.300.30

AA44 0.217 0.480.48

MCDM METHOD APPLICATION: MCDM METHOD APPLICATION: TOPSISTOPSIS (Yoon(Yoon--Hwang 1980)Hwang 1980)SELECTION OF THE SELECTION OF THE BEST ALTERNATIVEBEST ALTERNATIVE

GFRP

STEEL

R.C

BASE

BRACING

JACKETS

ISOLATION

DISCUSSION OF RESULTSDISCUSSION OF RESULTS- The ranking results to be: 1) Confinement by GFRP

2) RC jacketing3) Base isolation4) Steel bracing

- Small dimensions (plan)- Residential destination- Decision maker profile (owner)

- Influence of the building’s peculiarities:


- MCDM procedures, applied to the specific case of interest, may represent an effective support to this selection, allowing to take into account simultaneously and in a concise, quantitative manner all the different points of view by which each alternative has to be evaluated.

- A best seismic retrofit solution in absolute terms does not exist. The selection of the best intervention strictly depends on the particular case under exam.

CONCLUSIONSCONCLUSIONS- Given a building to be seismically upgraded, the selection of the “best” (more suitable) retrofit alternative among the several ones available can be not a trivial task.

FUTURE DEVELOPMENTSFUTURE DEVELOPMENTS

- Close the case study (useful to define the procedure) and apply the decision method to other structures.

- Compare other type of interventions.

- Compare also different management strategies.i.e. Phased retrofit (for economic constraints or to not disturb certain activities or for other particular reasons, the retrofit can be organized in subsequent phases)

- Extend the decisional procedure from the single building to a group of existing structures to be upgraded: territorial scale.

i.e. Adding damping by passive or semi-active devices.


One-Day Research ShowcaseNovember 14th 2006

Universitàdi Napoli

Federico II

THANK YOU

multi-criteria decision analysis in seismic nicola caterino · 2006. 9. 21. · nicola caterino...

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