CALCULATION OF COSTS CALCULATION OF COSTS FOR SEISMIC RETROFIT FOR SEISMIC RETROFIT

OF STONE MASONRY OF STONE MASONRY BUILDINGS IN GREECEBUILDINGS IN GREECE

Maria BOSTENARU DANMaria BOSTENARU DAN

Gregor BOURLOTOSGregor BOURLOTOS

OverviewOverview

► IntroductionIntroduction►Description of the stone masonrDescription of the stone masonry built y built

stock in Greecestock in Greece►Description of the retrofit measuresDescription of the retrofit measures►Determination of costsDetermination of costs►Discussion and conclusionsDiscussion and conclusions

IntroductionIntroduction

►The majority of population lives in existing The majority of population lives in existing buildings and will further live in thesebuildings and will further live in these

►BBuildinguilding retrofit retrofit is important for their is important for their assurance in earthquake prone regionsassurance in earthquake prone regions

►Ressources are limited, therefore Ressources are limited, therefore economic efficienceconomic efficiency is importanty is important

►Stone masonry spread in GreeceStone masonry spread in Greece►Building element method from Germany, a Building element method from Germany, a

method which doesn’t require databasesmethod which doesn’t require databases

Description of the stone Description of the stone masonry built stock in Greecemasonry built stock in Greece

►Tassios and Syrmakezis (2004) WHETassios and Syrmakezis (2004) WHE►Historic centres of Greek citiesHistoric centres of Greek cities►Seismic performance is poorSeismic performance is poor►Load bearing structure: unreinforced Load bearing structure: unreinforced

stone masonry walls out of rubble stone masonry walls out of rubble stone with lime mortarstone with lime mortar

►floor and roof structures: timber floor and roof structures: timber structuresstructures

Description of the stone Description of the stone masonry built stock in Greecemasonry built stock in Greece

►Damaged in the Athens 1999 earthquake:Damaged in the Athens 1999 earthquake: partial collapse of walls, partial collapse of walls, collapse of corners, collapse of corners, separation of the two walls converging at a separation of the two walls converging at a

cornercorner extensive crackingextensive cracking

►Vertical and horizontal reinforced Vertical and horizontal reinforced concrete confining elements improve the concrete confining elements improve the behaviourbehaviour

Description of the stone Description of the stone masonry built stock in Greece masonry built stock in Greece

(source: WHE)(source: WHE)

Description of the retrofit Description of the retrofit measuresmeasures

►Retrofit measures in case of pre-Retrofit measures in case of pre-damaged buildingsdamaged buildings

►Strengthening of a non-damaged Strengthening of a non-damaged buildingbuilding

Retrofit measures in case of pre-Retrofit measures in case of pre-damaged buildingsdamaged buildings

►Extensive crackingExtensive cracking►Buckling of masonry wallsBuckling of masonry walls

Retrofit measures in case of Retrofit measures in case of extensive crackingextensive cracking

►the plaster is largely removed,the plaster is largely removed,►the rift is enlarged to several centimetres the rift is enlarged to several centimetres

with hammer and chipper,with hammer and chipper,►the rift is cleaned with air under pressure,the rift is cleaned with air under pressure,►the rubble rests are removed,the rubble rests are removed,►the rift is filled with cement or reparation the rift is filled with cement or reparation

mortar,mortar,►the plaster is re-established.the plaster is re-established.

Retrofit measures in case of Retrofit measures in case of extensive crackingextensive cracking

Retrofit measures in case of Retrofit measures in case of buckling of masonry wallsbuckling of masonry walls

►the loads are catched with a support the loads are catched with a support and lead into the load bearing and lead into the load bearing foundation,foundation,

►the old wall is demolished,the old wall is demolished,►a new wall is built,a new wall is built,►the wall is loaded again (the support is the wall is loaded again (the support is

unmounted).unmounted).

Retrofit measures in case of Retrofit measures in case of buckling of masonry wallsbuckling of masonry walls

Retrofit measures as preventive Retrofit measures as preventive measuresmeasures

►Retrofit measures in case of lack of Retrofit measures in case of lack of confinement of the cornerconfinement of the corner

►Retrofit measures in case of non Retrofit measures in case of non corresponding confinement of the corresponding confinement of the openingsopenings

►Shotcreting of the wallShotcreting of the wall►Creation of a ring beamCreation of a ring beam

Retrofit measures in case of lack Retrofit measures in case of lack of confinement of the cornerof confinement of the corner

► the roof and floor loads are caught with a the roof and floor loads are caught with a scaffold construction,scaffold construction,

► it is bolted in two directions on the inner it is bolted in two directions on the inner side of the wall,side of the wall,

► the masonry is demolished and disposed,the masonry is demolished and disposed,► the corner column is reinforced,the corner column is reinforced,► forming – concreting – stripping of the forming – concreting – stripping of the

corner column,corner column,► creating reinforced masonry in the zone of creating reinforced masonry in the zone of

the corner column.the corner column.

Retrofit measures in case of lack Retrofit measures in case of lack of confinement of the cornerof confinement of the corner

Unloading of the wall in order to add confinement

Retrofit measures in case of lack Retrofit measures in case of lack of confinement of the cornerof confinement of the corner

Retrofit measures in case of non Retrofit measures in case of non corresponding confinement of corresponding confinement of

the openingsthe openings► the old door and door frame are demolished the old door and door frame are demolished

and disposed,and disposed,► the eventually existing lintel is also the eventually existing lintel is also

demolished and disposed,demolished and disposed,► the masonry adjacent to the door opening is the masonry adjacent to the door opening is

demolished and disposed,demolished and disposed,► the reinforcement of the reinforced concrete the reinforcement of the reinforced concrete

frame is anchored in the floor slab,frame is anchored in the floor slab,► the other reinforcement works are done,the other reinforcement works are done,► it is formed – concreted – stripped,it is formed – concreted – stripped,► the new door is introduced.the new door is introduced.

Retrofit measures in case of non Retrofit measures in case of non corresponding confinement of corresponding confinement of

the openingsthe openings

Retrofit measures in case of non Retrofit measures in case of non corresponding confinement of corresponding confinement of

the openingsthe openings

Shotcreting of the wallShotcreting of the wall

► removal of the plaster,removal of the plaster,► removal of the mortar up to 1 cm deep with removal of the mortar up to 1 cm deep with

a steel brush,a steel brush,► cleaning the wall with water,cleaning the wall with water,► shotcreting in a thickness of 4-8 cm. shotcreting in a thickness of 4-8 cm.

Alternatively a cast in place concrete Alternatively a cast in place concrete jacketing of 10 cm thickness can be done. jacketing of 10 cm thickness can be done. The reinforcement has a diameter of 8/25. The reinforcement has a diameter of 8/25. The new wall has to be anchored in the The new wall has to be anchored in the existing masonry wall.existing masonry wall.

Shotcreting of the wallShotcreting of the wall

Determination of costsDetermination of costs

►Overview of German costs estimation Overview of German costs estimation methodsmethods

►Approach to costs calculation of Approach to costs calculation of retrofit methodsretrofit methods

►Examples of costs calculationExamples of costs calculation

Overview of German costs Overview of German costs calculation methodscalculation methods

Costs estimation: Costs estimation: ►building divided in spaces with different building divided in spaces with different

functionsfunctions►database necessary database necessary ►suitable in incipient stages of planningsuitable in incipient stages of planning

Costs calculationCosts calculation►Building elements divided according to their Building elements divided according to their

execution typeexecution type►Later stages of planning, more preciseLater stages of planning, more precise►Different levels of deepnessDifferent levels of deepness

►Neddermann: old building elementsNeddermann: old building elements

Approach to costs calculation of Approach to costs calculation of retrofit measuresretrofit measures

►Retrofit elementsRetrofit elements recognition characteristics,recognition characteristics, construction works with duration/needed construction works with duration/needed

resources,resources, implied works for retrofit/reparation,implied works for retrofit/reparation, earthquake resilient features, seismic earthquake resilient features, seismic

deficiencies and earthquake damage deficiencies and earthquake damage patternspatterns

Examples of costs calculationExamples of costs calculation

►Reparation of cracking in the wallsReparation of cracking in the walls►Reparation of buckled wallsReparation of buckled walls►Retrofit of cornersRetrofit of corners►Retrofit of door framesRetrofit of door frames

Reparation of cracking in the Reparation of cracking in the walls: small rifts in non-bearing walls: small rifts in non-bearing

walls walls No. Operation Unit Working time/un

it

Price/unit (€)

Number of units

Price / time (€)

Whole price (€)

1 Removal of the plaster on big surface

m 0.3 h 1 36 10.8

2 Enlarging the rift with hammer and chisel

m 0.2 h 1 36 7.2

3 Cleaning the rift m 0.1 h 1 36 3.6

4 Filling the rift with mortar

m 0.1 h 1 36 3.6

Reparation mortar m 5 1 5

5 Transport of the removed plaster to container

m 0.07 h 1 36 2.52

6 Disposal of the removed plaster

m³ 13+18.40 0 0.05

7 New plaster m 0.14 h 36 5.04

Plaster mortar m 2.5 1 2.5

Price m rift 40.31

Reparation of cracking in the Reparation of cracking in the walls: rifts in load bearing walls walls: rifts in load bearing walls

No. Operation Unit Work time/unit

Price/unit (€)

Number units

Price/ time (€)

Whole price (€)

1 Large removal of the plaster m 0.3 1 36 10.8

2 Preparation of the base m 0.2 1 36 7.2

3 Drilling m 0.2 1 36 7.2

4 Cleaning of the drill holes m 0.2 1 36 7.2

5 Battering the packer m 0.2 1 36 7.2

6 Isolating m 0.2 1 36 7.2

7 Verifying the patency m 0.2 1 36 7.2

8 Turning in the nipples m 0.2 1 36 7.2

9 Injection m 0.2 1 36 7.2

Injection means m 5 1 5

10 Postinjection m 0.2 1 36 7.2

11 Removing the isolation m 0.2 1 36 7.2

12 Chipping out the packer m 0.2 1 36 7.2

13 Closing the drill hole m 0.2 1 36 7.2

14 Disposal of the removed plaster m³ 13+18.4 0 0.05

15 New plaster m 0.14 1 36 7.2

Plaster mortar m 2.5 1 2.5

Price m rift 111.95

Reparation of buckled wallsReparation of buckled walls

No. Operation Unit Work time/ unit

Price/unit (€)

Number of units

Price /time (€)

Whole price (€)

1 Bolts to support the floor piece 2 h 1 36 72

2 Demolition of masonry m³ 5,6 h 1 36 201.6

3 Disposal of demolished masonry

m³ 13+6 1 19

4 Stonewalling of the demolished walls

m³ 5.48 h 1 36 197.3

Stones piece 0.25 275 68.75

Mortar litre 3.125/27 233 26.96

Price m³wall

585.61

Retrofit of cornersRetrofit of cornersNo. Operation Unit Work

time/unit

Price/unit (€)

Number of units

Price/time (€)

Whole price

1 Bolten in two directions piece 2 h 1 36 72

2 Demolition of masonry m³ 5.6 h 4.38 36 883.01

3 Disposal of the demolished masonry m³ 13+(46/2.5) 4.38 137.53

4 Reinforcement of the corner column piece 0.5 h 1 36 18

Steel (100kg/m³ concrete) t 500 0.05 25

5 Forming the corner column piece 20 min 1 36 13.5

Formwork m² - 8.5 10 - 85/4

Formwork support m - 0.55 25 - 13.75/4

6 Concreting the corner column piece 1 h 1 36 36

Concrete m³ 140 0.48 67.2

7 Striking the corner column piece 20 min 1 36 13.5

8 Stonewalling the demolished walls (20% more height for the anchoring of the reinforcement)

m² 2 h 9.6 36 691.2

Masonry stones stone 250/1000 pieces

960 240

Mortar litre 3.125/27 l 816 94.44

Price corner 2448.69

Confinement of door framesConfinement of door framesNo. Operation Unit Work time/

unitPrice/unit (€) Number of

unitsPrice/ time (€) Whole price

1 Demolition of the door and the door frame including the transport to the building site rubble container

door 0.5 h 1 36 18

2 Disposal of the doorframe and the door t 225 0.04 9

container 46 0.25 11.5

3 Demolition of the masonry including the transport to the building site rubble container

door 0.5 h 1 36 18

4 Disposal of the demolished masonry m³ 13+46/2.5 0.3 9.42

5 Cleaning of the demolished masonry rests with steel brush in order to remove rubble rests

door 0.5 h 1 36 18

6 Reinforcement steel of the door frame out of reinforced concrete anchored in the floor

hole 0.5 h/ 8 holes 8 36 18

7 Reinforcement door 45 min. 1 36 27

Steel t 500 0.02 7.5

8 Forming (the door frame has the function of framework for concreting)

door 20 min 1 36 13.5

9 Concreting door 1 h 1 36 36

Concrete m³ 140 0.3 42

10 Stripping the forms door 20 min 1 36 13.5

11 Acquisition of the door and assembly piece 368 1 368

Price doorframe

609.42

Discussion and conclusionsDiscussion and conclusions

►The employment of the method doesn’t The employment of the method doesn’t improve the whole buildingimprove the whole building

►Employed in the past years more and Employed in the past years more and more in Greecemore in Greece

► In Greece stone buildings experience at In Greece stone buildings experience at least an earthquake during their lifetimeleast an earthquake during their lifetime

►Targeted measures are task of the Targeted measures are task of the engineersengineers

Discussion and conclusionsDiscussion and conclusions

No.

Measure Costs

1 Small rifts in non-bearing masonry walls 40.31 € / m rift

2 Rifts in load bearing masonry walls 111.95 €/ m rift

3 Rehabilitation of buckled masonry walls 585.61 € / m³

4 Confinement of masonry corners 2448.69 € /corner

5 Confinement of door frames 609.42 € /door frame

Discussion and conclusionsDiscussion and conclusions

►Stone masonry houses spread Stone masonry houses spread throughout the world:throughout the world: Algeria, India, Iran, Italy, Nepal, Pakistan, Algeria, India, Iran, Italy, Nepal, Pakistan,

Portugal, Slovenia, and Switzerland (WHE)Portugal, Slovenia, and Switzerland (WHE) historic, heritage buildingshistoric, heritage buildings no databases of previous performed worksno databases of previous performed works

►The method is useful, all needed are The method is useful, all needed are prices of materials and of the hour of prices of materials and of the hour of workwork

►No affirmation about certaintyNo affirmation about certainty

Discussion and conclusionsDiscussion and conclusions

►Research into the structural behaviour Research into the structural behaviour of seismic retrofit measures is much of seismic retrofit measures is much more spread than in the side of more spread than in the side of application and economic efficiency. application and economic efficiency.

►The work presented here builds a The work presented here builds a begin.begin.

Thank you!Thank you!