ROSE Seminar

Assessment of the impact of

seismic retrofit on 1920-1940

reinforced concrete blocks of flats

Maria BOSTENARU

Rui PINHO

CA‘REDIVIVUS project

The title

=

Reinforced Concrete

CASA REDIVIVUS

Cemento Armato

HOUSE TO NEW LIFE


objectives

(measures package)

objective

(measure)

scientific method

instruments

step

goal

Methodology


Step Goal Method Instrument Measure

1 technical reports on implementation

programmes

documentation investigation

training.

4; 8

2 a data table of use for the decision

method in the next step

parametrical study FEM 2

3 support the choices at step 4 and step

1

highlighting

comprehensibility

database 7

4 algorithm based on case studies (step

2) for experiments (step 6)

modularisation of the

decision model

pair wise

comparison

3

5 report about available systems for this

purpose

a basis system to

administrate modules

computer tools 6

6 trial of educational feasibility (step 3) project example exercise 5

7 dissemination of results presentation publications 1

Nr. Measures package Method Interest groups

1 improving understanding of the

impact of earthquakes

- public presentation

- reaction to feedback on findings Multidisciplinary

2 development of an algorithm for

optimisation of retrofit measures

parametrical study -

3 development of a decentralised

decision model

modularisation of a collaborative

decision model

Interdisciplinary

4 insights into applicability of

retrofit methods

documentation

training

Interdisciplinary

architecture

engineering

5 development of a framework for

integral planning

retrofit design model project for the

integral planning

Interdisciplinary

architecture

engineering

economics

6 solving contradictions between

the objectives of single actors

develop a basis system to administrate

modules on different levels

Multidisciplinary

7 highlighting the comprehend-

sibility of the measures analysed

physical implementation flow along

with an education flow for population

which has to support the measures

architecture

urbanism

sociology

8 support changes by political and

economic environment:

document existing programmes

impact assessment

-

Methodology


Modernism

a global movement in architecture, music, arts, physics, philosophy, economic and social theory and industrialisation in the first half of the 20th century

one of the nuclei: housing programme

Industrial development > new technologies > reinforced concrete > innovation


Modernism

Western Europe: social housing

other: new image to capital cities, housing for the middle class in preferential areas

CIAM and Charter of Athens (1933): functionalism

Seismic issues neglected

Nostalgy for that time in Greece and Romania


The Charter of Athens

1933

Organisation of cities in functional zones

Bucharest Master Plan 1934 > design of buildings in the interwar time

• Ground occupancy > planimetric irregularity

• Raised permitted height to define streets by their fronts > set-back floors

• Encouraged mixed use in central zone


Comparative analysis

Romania Greece Italy Portugal

location capital capital N (Como, Milano) capital

city centre

close to the railway station

city centre,

close to the railway station

Development boulevards N

EQ damage

2 EQs one EQ none none

maintenance poor mixed good good

architect numerous several several Cassiano Branco

programme residential residential, school

residential, offices

residential, hotels


Greece

Athens: absence of town planning applications

Extensions section by section, on rudimentary street layouts > parcels of rectangular contour result; the parcels are like for individual dwellings

Small blocks, but parcels bigger than in Bucharest


Greece

Morphologic language: cubist and ornamentless structures, like on the islands

1929: new legislation

• Multiple ownership of blocks of flats

1925 establishment of Reinforced concrete as material for load-bering structures of buildings

Buildings have 5-6 storeys


Greece


Bedroom / night zone

Living room, including dinning

Corridors / circulation zone

Bathrooms, toillets

Kitchen

Hall / vertical circulation

Deposit / external circulation

Legend:

Functional scheme in a

Greek apartment building


Romania

End of XIXth century: Haussmannian intervention of tracing main boulevards in the city: major throughfares and irregular parcels on them resulted, fully occupied

Urban section of Modern buildings with no equal in Europe (in other places historic centres completed long before); middle class housing


Romania

Bucharest Master Plan 1934, one year after the CIAM in Athens

Main traffic routes reinforced by the street facade, cornice raised to 24m on the N-S boulevard, higher at intersection corners > set-backs

Mixed use with cinemas and shops

The height of the building varied from 2-3 to 12 floors


Romania

Earthquakes 1940 and 1977

In 1940 Carlton building collapsed

1977 about 30 buildings built 1920-1940 collapsed

ARO building, restored after a fire, behaved well

The buildings were replaced by new ones of less architectural value and the unity of the boulevard was destroyed


Romania

The reinforced concrete structure permitted flexibility in the organisation of the floor and among the floors

No moment resisting frames > RC scheleton, sometimes with masonry infill > seismic vulnerability


Romania


Functional scheme in a

Romanian ap. building

Bedroom / night zone

Living room, including dinning

Corridors / circulation zone

Bathrooms, toillets

Kitchen

Hall / vertical circulation

Deposit / external circulation

Legend:


Structural scheme of a

Romanian apartment building


Seismic features

Element Seismic Deficiency

Earthquake Resistent Features

Earthquake Damage Patterns

Infill panels consoles Increasing stiffness rifts

Columns No moment resisting frames

Low reinforcement

- Plastic hinges at soft storey

Concrete spalling

Beams No moment resisting frames

Well reinforced Plastic hinge in long beams

Oblique rifts in short beams

Roof and Floors

too elastic Alternative solutions with embeded bricks

More rifts at stair flights


Italy

At the begin of the century:

• Arte Nuova and Futurism

• Reasoned picturesque (edilizia cittadina)

Reasoned picturesque and enthusiasm for the vernacular building > contextualism (l‘ambientismo)

Contextualism will be maintained in Italian Rationalism also.


Italy

Urban planning approch in Italian architecture begun well before the CIAM

1920-1940:

• Milanese Novecento – housing for the middle class, flexibility in RC, stappeled villa, serial building plan

• Italian Rationalism – innovated volumes and facades, building plans remained conventional


Italy


Portugal

Reinforced concrete

Boulevards of haussmannian type N of the city > geometric parcels

Cassiano Branco, typology easy to repeat


Portugal


Historical

Building

Element

Material

Vulnerability

Structure

performance

Retrofit

elements

Strategy

Architect Engineer

Inhabitant Investor

Execution

Acceptance

Occupancy

Management

Availability

Indicators

Residential value

Reversibility

Guidelines

Displacement, maximal

Tension

Facade

Interior space

Structure

Demolition

Size change

Looks change

Construction material change

Material

Earthquake

Shape score

Structure score

Forces

Displacement, remaining

Element replacement

New element

Non-structural > structural

System completion

Strengthening/Stiffening

Enhanced ductility

Reduced demand

Duration

Noise

Relocation

Participation

Ownership form

Safety

Own expenses

Other benefits

During measure

After measure

After earthquake

Total costs/New bldg. – 30%

Aggregate

Building site

Phases

Repeatability

Construction material versus

Technology versus

Funds

Relocation space

Reparation/New building

Retrofit/New building

Reparation saving/Retrofit

Compatibility with old

Conservation of old

Maintenance new

Sustainability

Partial demolition

Historical

Building

Element

Material

Vulnerability

Structure

performance

Retrofit

elements

Strategy

Architect Engineer

Inhabitant Investor

Execution

Acceptance

Occupancy

Management

Availability

Indicators

Residential value

Reversibility

Guidelines


Tension

Facade

Interior space

Structure

Demolition

Size change

Looks change


Material

Earthquake

Shape score

Structure score

Forces


Element replacement

New element


System completion


Enhanced ductility

Reduced demand

Duration

Noise

Relocation

Participation

Ownership form

Safety

Own expenses

Other benefits

During measure

After measure

After earthquake


Aggregate

Building site

Phases

Repeatability


Technology versus

Funds

Relocation space





Conservation of old

Maintenance new

Sustainability

Partial demolition


Urban – building scale

interdependenceZONE B

ZONE AZONE C

BUILDING Y

BUILDING XBUILDING Z

ELEMENT α

ELEMENT β

ELEMENT γ

ma

rketin

gm

an

agem

en

tp

artic

ipatio

nco

nsi

sts

of


Number Legend

Volume height accents 47 (incl. 12 with aesthetic

qualities; 1 negative)

bordeaux-

red-orange

volume silhouette accents 4 blue

functional landmarks 1 triangles

aesthetic qualities 9+12 blue strips

negative value 4+1 black strips

Mapping of the hierarchy of the elements and of the façade (fronts

typology: continuous line = continuously built front, interrupted and

continuous line = front full with alveolar injections, interrupted line = front broken by isolated buildings and vegetation, point line =

unstructured front; hierarchy of perception points: dark green =

intersection place, turquoise = reverence place, magenta = private/half-private space, grey lines = public space with half-private character, light

green = public environmental space, dark magenta = public space).

Urban scale - IMPACT


Historical

Building

Element

Material

Vulnerability

Structure

performance

Retrofit

elements

Strategy

Architect Engineer

Inhabitant Investor

Execution

Acceptance

Occupancy

Management

Availability

Indicators

Residential value

Reversibility

Guidelines


Tension

Facade

Interior space

Structure

Demolition

Size change

Looks change


Material

Earthquake

Shape score

Structure score

Forces


Element replacement

New element


System completion


Enhanced ductility

Reduced demand

Duration

Noise

Relocation

Participation

Ownership form

Safety

Own expenses

Other benefits

During measure

After measure

After earthquake


Aggregate

Building site

Phases

Repeatability


Technology versus

Funds

Relocation space





Conservation of old

Maintenance new

Sustainability

Partial demolition

Historical

Building

Element

Material

Vulnerability

Structure

performance

Retrofit

elements

Strategy

Architect Engineer

Inhabitant Investor

Execution

Acceptance

Occupancy

Management

Availability

Indicators

Residential value

Reversibility

Guidelines


Tension

Facade

Interior space

Structure

Demolition

Size change

Looks change


Material

Earthquake

Shape score

Structure score

Forces


Element replacement

New element


System completion


Enhanced ductility

Reduced demand

Duration

Noise

Relocation

Participation

Ownership form

Safety

Own expenses

Other benefits

During measure

After measure

After earthquake


Aggregate

Building site

Phases

Repeatability


Technology versus

Funds

Relocation space





Conservation of old

Maintenance new

Sustainability

Partial demolition


Italy

Participatism


Case study HaDiKo


Historical

Building

Element

Material

Vulnerability

Structure

performance

Retrofit

elements

Strategy

Architect Engineer

Inhabitant Investor

Execution

Acceptance

Occupancy

Management

Availability

Indicators

Residential value

Reversibility

Guidelines


Tension

Facade

Interior space

Structure

Demolition

Size change

Looks change


Material

Earthquake

Shape score

Structure score

Forces


Element replacement

New element


System completion


Enhanced ductility

Reduced demand

Duration

Noise

Relocation

Participation

Ownership form

Safety

Own expenses

Other benefits

During measure

After measure

After earthquake


Aggregate

Building site

Phases

Repeatability


Technology versus

Funds

Relocation space





Conservation of old

Maintenance new

Sustainability

Partial demolition

Historical

Building

Element

Material

Vulnerability

Structure

performance

Retrofit

elements

Strategy

Architect Engineer

Inhabitant Investor

Execution

Acceptance

Occupancy

Management

Availability

Indicators

Residential value

Reversibility

Guidelines


Tension

Facade

Interior space

Structure

Demolition

Size change

Looks change


Material

Earthquake

Shape score

Structure score

Forces


Element replacement

New element


System completion


Enhanced ductility

Reduced demand

Duration

Noise

Relocation

Participation

Ownership form

Safety

Own expenses

Other benefits

During measure

After measure

After earthquake


Aggregate

Building site

Phases

Repeatability


Technology versus

Funds

Relocation space





Conservation of old

Maintenance new

Sustainability

Partial demolition


Phasing of retrofit

1st phase

2nd phase


Layout of retrofit elements

1st phase

2nd phase


Retrofit options

pushover Y

0

1000

2000

3000

4000

5000

6000

-50 0 50 100 150 200 250 300 350 400

Displacement N6206

Base s

hear

(N)

Base Shear Y

Base Shear Y retrofit2

Base Shear Y retrofit3

160

Base Shear Y concretejacketing

higher disturbance

medium disturbance

lower disturbance

original


Demolition

Vulnerability

Retrofit

Structural

performance

Strategy

Building

Historical

Element

Material

EngineerArchitect

InvestorUser

Management

Availability

Indicators

Execution

Acceptability

Use

Residential value

Earthquake

Shape score

Material

Element replacement

New elements


Partial demolition

Forces

Maximal displacement

Stresses

Facade

Interiors

Structural system

Reversibility

Guidelines

Size change

Looks change

Material change

Compatibility

Conservation

Maintenance

Aggregate

Building site

Phases

Repeatability

Material versus

Technologie v.

Replace space

Reparation/Rebuild

Reparation-saving/Retrofit

Total costs/Rebuild – 30%

Duration

Noise

Move

Participation

Property form

Assurance

Own costs share

Other advantages

During measure

After measure

After earthquake

Remaining displacement

Structure score

Sustainability

Funding money

Retrofit/Rebuild

50%15%

20%15%

50%

15%

15%

10%

50%

30%

10%

10%

70%

10%

40%

40%

20%

50%

50%

30%

30%

10%

30%

40%

20%

40%

30%

50%

10%

30%

15%

5%

70%

70%

15%

70%

10%

30%

30%

50%

20%

10%

30%

30%

30%

50%

15%

20%

15%

20%

30%

30%

20%

20%

20%

10%

50%

25%

25%

25%

25%

20%

Reduced demand

Enhanced ductility

StrengtheningStiffening

System completion

10%

55%

30%

5%

10%

10%

30%

40%

20%


Conclusions

typological study

Athens (Charter proclaimed), Bucharest (Charter applied) considered for the model

Greek and Romanian blocks of flats:

• mixed use (commercial functions at GF, residential above)

• Greek buildings: 5-6 storeys

• Bucharest, zone dependent, 2-12 floors


Conclusions

economic development, framework also given in Portugal and Italy,

possibility to employ new technologies: RC.

The model building: compromise between the Greek and the Romanian typology

• six storeys

• a regular array (2.4, 3.6 and 6m span) of columns (Greek)

• irregular planimetry

• section typical for Romanian parcels


Conclusions

Different countries, different frame conditions

• Romania: irregularity of buildings > addition of structural elements

• Greece: lack of ductility> FRP wrapping

• Italy: no seismic hazard in this zone

• Portugal: small sample of buildings of that type


Conclusions

The decision tree has shown that it is a difficult problem to satisfy the contradicting goals of the interest groups considered.

Thank you!

Questions?

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