Examples of SHM on Cultural Heritage Structures · SHM on Cultural Heritage Structures 03.02.2016. Zagreb Investigated structures 1] St. Mary’s Church in Beram, Istria The St. Mary’s

University of Zagreb, Faculty of Civil Engineering Department of Engineering Mechanics Kačićeva 26, Zagreb, Croatia www.grad.unizg.hr

SHM on Cultural Heritage Structures 03.02.2016.

Zagreb

Examples of…

SHM on Cultural Heritage Structures University of Zagreb, Faculty of Civil Engineering

Department of Engineering Mechanics

CREATED BY:

Assist.prof. Domagoj Damjanović, Ph.D.C.E Postdoc. Ivan Duvnjak, Ph.D.C.E

Postdoc. Marko Bartolac, Ph.D.C.E Assistant Janko Košćak, M.C.E



Zagreb

Introduction

× Department of Civil Engineering Mechanics as a part of Faculty of Civil Engineering in Zagreb is carrying structural health monitoring on the structures of cultural heritage located in Republic of Croatia for many years. As part of this presentation studies conducted on some of these structures will be shown.

Rector’s Palace, Dubrovnik

Peristyle, Split

St. Mary’s Church, Beram

Old bridge, Sisak Revelin fortress, Dubrovnik



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Locations of investigated structures


Old bridge, Sisak

Peristyle, Split

Rector’s Palace & Revelin fortress, Dubrovnik



Zagreb



Old bridge, Sisak

Peristyle, Split




Zagreb

Investigated structures

1] St. Mary’s Church in Beram, Istria

The St. Mary’s Church is a small chapel in the woods outside Beram in Istria. The interior of the church is covered in frescoes, including a portrait of Saint Martin, the Triumphal Entry into Jerusalem, the Last Supper, and other conventional subjects. The frescoes were commissioned by Beram Confraternity of St. Mary, so most are dedicated to the lives of Mary and Jesus. But the star of the show is a "dance of death" painted by Vincent de Kastav in 1474. In this version of the dance macabre, Skeletons walk in procession from right to left, led by a skeleton playing bagpipe.

St. Mary’s Church, Beram Dance of Death by Vincent de Kastav



Zagreb



PROBLEM

As a result of subsidence of foundations, the cracks od the main load bearing wall appeared.



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PROBLEM MEASUREMENTS

Eight inductive transducers were installed which measured expansion and contraction of cracks on load bearing elements.

In addition, inner and outer temperature was recorded during measurements.



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PROBLEM MEASUREMENTS RESULTS

0

3

7

10

13

17

20

23

27

30

33

37

40

-0,20

-0,15

-0,10

-0,05

0,00

0,05

0,10

0,15

0,20

0,25

0,30

0,35

0,40

14.4. 26.4. 8.5. 20.5. 1.6. 13.6. 25.6. 7.7. 19.7. 31.7. 12.8. 24.8. 5.9. 17.9. 29.9.11.10.23.10.

Te

mp

era

ture

[C

°]

Cra

ck m

ou

th d

isp

lace

me

nt

[mm

]

Time [date.month]

Crack mouth displacement - CH7 Outside temperature - CH9

0,3

mm

CONCLUSIONS

Increasing of the crack mouth displacement on south load bearing wall was detected.



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Old bridge, Sisak

Peristyle, Split




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2] Old bridge, Sisak

The bridge was built in 1934. as a replacement to an older wooden bridge dating from 1862. At a time when the concrete was already in widespread use, this bridge was built from traditional materials, stone and brick, which highlight its graceful forms. The citizens spontaneously named it „Stari most” (Old bridge), eventually the name became official and the bridge became one of the symbols of the city of Sisak.

Old bridge in Sisak



Zagreb


PROBLEM

Extensive damage of non load bearing elements were observed especially visible on the heads of the columns and on the edge of the arch. Stability and durability of the structure were threatened with the direct penetration of precipitation from the road surface into the interior structure of the bridge. Another important phenomenon that threatened the sustainability and stability of the structure was condensation in the form of droplets of water on the surfaces of load bearing elements of the bridge structure.




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1] Compressive strength of concrete slab was determined on 14 test specimens taken on the field.

U1 S1 S2 S3 U2

V1 V2 V3 V4 V5 V6 V7 V8 V9 V10 V11

SOUTH

NORTH River Kupa

V5' V7' V8'

2] Compressive strength of masonry and stone elements was also determined on 14 test specimens.

S2



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3] Corrosion parameters of structural elements of the bridge were measured.

U1 S1 S2 S3 U2

SOUTH

NORTH River Kupa

4] Structural health monitoring was installed.

1

2

3

7 8

4

56

EAST

1 - 6 – STRAIN MEASUREMENT

7 - 8 – CRACK MOUTH OPENING MEASUREMENT

9 – TEMPERATURE AND HUMIDITY

A – DATA AQUISITON CENTER

9

S2

A WEST

Measured parameters: displacements strains cracks opening temperature and relative humidity



Zagreb



PROBLEM MEASUREMENTS RESULTS

-4

0

4

8

12

16

20

24

28

32

36

40

-0,18

-0,16

-0,14

-0,12

-0,1

-0,08

-0,06

-0,04

-0,02

0

0,02

0,04

10.2

012

1.2

013

4.2

013

7.2

013

10.2

013

1.2

014

4.2

014

7.2

014

10.2

014

1.2

015

4.2

015

7.2

015

10.2

015

1.2

016

Te

mp

era

ture

[°C

]

Str

ain

[‰

]

Time [month.year]

CH1 - strain CH4 - Strain Temperature

CONCLUSIONS

Measured strain values are low. Monitoring is still active!



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Old bridge, Sisak

Peristyle, Split




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3] Peristyle of Diocletian’s Palace, Split

Peristyle, as the central square of the Diocletian’s Palace, intended for the Emperor Diocletian celebrated as the living son of Jupiter, finds its place among many temples. In November 1979 UNESCO, in line with the international convention on cultural and natural heritage, adopted a proposal that the historic city of Split built around the Palace should be included in the register of World Cultural Heritage.

Peristyle, Split Reconstruction of Diocletian’s palace by Hebrard



Zagreb


PROBLEM

The damages on masonry structures mainly relate to cracks, foundation settlements, material degradation and structural deformations. There are many techniques which are capable to detect and locate damages even if they are not visible on the surface of the structure. These limitations can be overcome by implementing monitoring system for measuring behaviour of the structure.




Zagreb


PROBLEM


MEASUREMENTS

1] The hole drilling method was used to measure the magnitudes of residual stresses. The residual strain measurement was performed in order to determine the actual force in the copper clamp (12 measuring points).

In addition, mechanical properties of the copper clamp were determined using tensile test.



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PROBLEM


MEASUREMENTS

2] Continuous static structural monitoring based on LabVIEW and CopmaqDAQ designed to capture the displacements, strains and temperature at discrete nodes of a structure was installed.

SG8

L7

Strain gauge - SG

LVDT - L

Temperature - TEMP TEMP

Legend:

L6

L5

L9

L10

L8



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PROBLEM


MEASUREMENTS RESULTS

-100

-50

0

50

100

150

200

250

300

350

400

450

500

550

600

14.6.14. 15.6.14. 16.6.14. 17.6.14. 18.6.14. 19.6.14. 20.6.14. 21.6.14. 22.6.14.

Str

ain

[μ

m/m

]

Time [day.month.year]

CH1 CH2 CH3 CH4

crack propagation detected

CONCLUSIONS

Current state of the structure is stable. Monitoring is still active!

Measured residual force [kN]



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Old bridge, Sisak

Peristyle, Split




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4] Rector’s Palace, Dubrovnik

According to records dating from the 13th century, a castellum surrounded by four corner towers was once located on the site on which the Rector's Palace is to be found today. The reconstruction of the fortress into the palace took place in the 14th century. After the demolition of the old Rector's Palace in the gunpowder explosion of 1435 the new palace was built in the late-Gothic style by Onofrio de la Cava. That is when the palace received its present form (a single - storey building with four wings closing the courtyard - a portico with a small mezzanine floor gallery and a large floor gallery).

Interior of the Rector’s Palace Rector’s Palace, Dubrovnik



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PROBLEM

Disastrous earthquake of 1667 damaged the building’s interior (columns and archer of the courtyard and the galleries). Last reconstruction took place in 1982/84 following the earthquake of 1979.




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PROBLEM

At nine representative and characteristic cracks sensors for monitoring of crack opening were installed. As the majority of sustained damages and cracks were located at the atrium area in the center of the palace, and further more at the small twin columns, that is where the most of the measuring points were located and most of the sensors installed. Two sensors (1st and 6th) were installed at the steel tie rods of the first floor in perpendicular directions.


MEASUREMENTS

Measuring points Block diagram of the monitoring



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PROBLEM


MEASUREMENTS RESULTS CONCLUSIONS

The aim of continuous long period monitoring of Rector's Palace structure behavior is to determine boundary conditions in order to create reliable numerical model of the structure for analysis which will define construction works needed to preserve stability of the structure.

Diagrams of crack growth for sensors 2, 5, 8 and 9



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5] Revelin fortress, Dubrovnik

On the eastern part of the City, outside Ploče City Gate, the massive fortress of Revelin is located. The initial fort was built in 1463, in the period of unmistakable Ottoman empire (Turk) threat, who have conquered Constantinople in 1453 and were about to occupy nearby Bosnia (occupied in 1463). Revelin was built as a detached fortress providing additional protection to the eastern City Gate. In 1538 the Senate approved Ferramolino's drawings of the new, much stronger Revelin. It took 11 years to build it, and during that time all other construction work in Dubrovnik had stopped in order to finish this fortress as soon as possible. The new Revelin became the strongest fortress of Dubrovnik, safeguarding the eastern land approach to the city. Revelin was finally completed in 1549.

Revelin fortress in Dubrovnik



Zagreb


PROBLEM

On the vaults of the hall of Revelin fortress cracks appeared, time and cause of crack appearance is unknown.




Zagreb


PROBLEM

Eight inductive transducers were installed which are measuring growth and contraction of cracks on the vaults.


MEASUREMENTS

Rh&TIn

1,23, 4 5, 6

Rh&TOut

Legend:

Crack growth measurement

Temperature and relative humidity

1 - 6

Rh&TU

Rh&TV

CRACK ICRACK IIICRACK II



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PROBLEM


MEASUREMENTS RESULTS CONCLUSIONS

-0,12

-0,1

-0,08

-0,06

-0,04

-0,02

0

0,02

0,04

11.11. 15.11. 19.11. 23.11. 27.11. 1.12. 5.12. 9.12.

Dis

pla

cem

en

t [m

m]

Time [day.month]

CH1 CH2 Monitoring was installed at the end of 2015. and no conclusions are shown in this presentation. Monitoring is still active!

Documents

Examples of SHM on Cultural Heritage Structures · SHM on Cultural Heritage Structures 03.02.2016. Zagreb Investigated structures 1] St. Mary’s Church in Beram, Istria The St. Mary’s