IRIS FP7-NMP-2007-LARGE-1 D11-1 - VCE · IRIS FP7-NMP-2007-LARGE-1 Iris Demonstration Report – Annex A page 3 of 24 Introduction The flyover S101 is a typical prestressed concrete

IRIS FP7-NMP-2007-LARGE-1

Iris Demonstration Report – Annex A page 1 of 24

D11-1

ANNEX A

PROJECT INFORMATION:

Project Title: INTEGRATED EUROPEAN INDUSTRIAL RISK

REDUCTION SYSTEM

Acronym: IRIS Contract N°: CP-IP 213968-2 Project N°: FP7-NMP-2007-LARGE-1

Project Start: 01 October 2008 Project End: 31 March 2012

REPORT INFORMATION:

Report Title: WP3 DEMONSTRATION REPORT – ANNEX A

Date of Issue: July 2009

Rep. Period: 01 October 2008 – 30 September 2009

Prepared by: VCE Holding GmbH

Authors: Wenzel, Helmut

Veit-Egerer, Robert

Widmann, Monika

Jaornik, Paul

coordinating person:

organisation:

e-mail:

fax:

telephone:

Dr. Helmut Wenzel

VCE Holding GmbH

[email protected]

+43-1-893 86 71

+43-1-897 53 39



IRIS (Integrated European Industrial Risk Reduction

System)

Bridge Object S101

(Reibersdorf / Upper Austria)

Progressive Damage Test

(10. – 13. 12. 2008)

Helmut Wenzel Robert Veit-Egerer

Monika Widmann Paul Jaornik

Carriageway Salzburg

Carriageway Vienna

South North

Cross section where tendons were cut through

Column which was lowered



Introduction

The flyover S101 is a typical prestressed concrete bridge from the early 1960ies. It was

decided to replace it due to insufficient carrying capacity and its maintenance condition

(both visual inspection driven rating). At the same time the bridge did not meet the

current requirements, as the structure did not fit into the overall traffic and

infrastructure concept anymore. In other words demolition was aspired anyway, because

the bridge was to small for the location.

The major objective of the current progressive damage test is to emphasize refined

methods for the analysis of upcoming, slowly progressing damage and its effects on

parameters of dynamic response.

In the course of the IRIS project VCE (together with the Alpine construction company

and the University of Tokyo) takes the opportunity of this certain damage test - given by

the bridge operator ASFINAG - to demonstrate the impact of scientific insight and

findings with regard to reduced uncertainties to support the decision process of

infrastructure owners in the course of cost planning for maintenance and possible

rehabilitation measures in general.

In the present report the followed measurement agenda from the 10th to the 13th of

December 2008 is documented. In the end the structuring of the recorded data into

several measurements is described.



Wednesday 10.12.2008

Weather observation:

Temperature: – 2°C; mist, easterly wind with approx. 2 m/s

Previous day: sunny weather – temp. -9°C in the morning, approx. -2° C at midday

Preparations for the progressive damage test - Evaluation of structural safety

with regard to the pier’s crossbeam and its foundation:

12:56 Start of operation of the BRIMOS-Recorder - placed at the western main

girder in the middle of the main span.

13:08 The supporting pier was hydraulically loaded with 120 t (250 bar – conform

to the bridge pier’s regular normal force)

13:25 The bridge was stressed with a test load of 144 t for a period of 10 min

(measurement S101REIT_081210A_MAINSPAN file S101REIT_01-05).

No cracks or any other indications of damage appeared at the structure

13:40 End of the load test. No reactions at the structure, no cracks or any other

indications of damage. Afterwards the load was taken away from the

supporting pier.

After that the BRIMOS sensor grid was set up and a geodetic levelling was

conducted.

17:16 Start of measurement with a dense BRIMOS sensor grid



Measuring system

Fig. 1: Sensor layout – BRIMOS Recorder; 10th of December 08

Tab. 1: Measurement specification - BRIMOS Recorder – 10th of December 08

Fig. 2: Sensor layout - BRIMOS sensor grid – 10th of December 08

position [m]

length cross

R1 (BRIREC) 28 6.2 Längs length

Quer crossVertikal vertical

sensor channel direction



Tab. 2: Measurement specification – BRIMOS sensor grid – 10th of December 08

position [m]

length cross

E105 56 6.2 weiss_laengs length

weiss_quer cross

weiss_vertikal vertical

E204 50 6.2 gruen_laengs length

gruen_quer cross

gruen_vertikal vertical

E210 47 6.2 braun_laengs length

braun_quer cross

braun_vertikal vertical

E103 44 6.2 gelbgruen_laengs length

gelbgruen_quer cross

gelbgruen_vertikal vertical

E202 40.8 6.2 schwarz_laengs length

schwarz_quer cross

schwarz_vertikal vertical

E201 37.6 6.2 lila_vertikal length

lila_quer cross

lila_vertikal vertical

E205 34.4 6.2 rot_laengs length

rot_quer cross

rot_vertikal vertical

E102 31.2 6.2 gelb_laengs length

gelb_quer cross

gelb_vertikal vertical

E101 28 6.2 blau_laengs length

blau_quer cross

blau_vertikal vertical

E207 28 1 E3_laengs length

E3_quer cross

E3_vertikal vertical

E209 24.8 6.2 E6_laengs length

E6_quer cross



E2_vertikal cross

E2_quer vertical


E5_quer cross


E104 12 6.2 E4_laengs length

E4_quer cross



E1_quer cross



Please pay attention to an exception between the German and English channel denomination




Thursday 11.12.2008


Temperature in the morning: – 1°; mist; no precipitation; no wind.

In the course of the day the temperature increased up to + 1°. The other weather

conditions remained unchanged.

Damage test lowering of a column – Additional restraint loading case:

07:00 preparing of the cutting line at the north-western column by the Seidl

company

07:35 Hydraulic loading of the supporting pier and increase up to 120 t; fixing with

adjusting collars

08:12 Start of cutting through the pier

08:35 the first cut is completed. No reaction, no noise, no spalling. A geodetic

levelling was conducted at the structure to fix the altitude of the points. All

measurement sensors are applied and in operation.

09:07 start of the second cutting – 10 cm above the first one.

09:33 finalisation of the second cut. No restoring forces observed

11:00 first lowering of the pier by 1 cm. The adjusting collar was released and

adjusted to 1 cm. Subsequently the pier was lowered rapidly and displaced at

the adjusting collar. A moderate noise of relaxation coming form the



supporting pier was noticed. No cracks or other indications of damage were

remarked at the structure. The lowering is clearly visible in the signal of the

laser-displacement channel. Alteration at the signals of the measurement

system. A slight decrease of the first eigenfrequency – already after the

cutting and before the first lowering of the pier - was also observed.

The plate of concrete which was cut out of the pier was examined in a

detailed manner. The concrete quality is very good. Only at one corner a

spalling in combination with rust is observable. The concrete reinforcement is

in remarkably good condition. The three bolts with a diameter of 26 mm were

actually at the position marked on the drawing. The quality is better than

having been expected after the visual inspection.

12:00 second step of lowering (second centimetre) analogue to the first step.

During the settling a displacement of 21 mm in direction to the middle of the

bridge was noticed at the column base. That reaction is not conform to the

finite element calculations. According to that there should be just a relatively

small inward reaction.

Within the next 2 hours no change (cracks or other indications of damage)

was noticed.

14:00 third step of lowering (third centimetre)

The lowering causes an additional horizontal displacement 10 mm. Due to the

fact that the elastic limit was reached at 7 mm of vertical deformation, the

total amount of additional 10 mm of lowering could not be accomplished.

Based on the performed static calculations the elastic limit was expected at

32 mm of vertical deformation instead of 27mm obtained in reality. This fact

can probably be explained by the low temperature during the test (influence

of already removed pavement ?). At the intact column – next to the lowered

one - a new horizontal crack appeared. The already existing cracks hadn’t

enlarged. It was decided to wait one hour to declare if phenomena of

structural creeping appear or if the structure remains in the same condition.

15:00 The gap between the adjusting collar and the hydraulic jack did not

disappear. This means that no non-linear processes causing a further

lowering of the column could be expected. Therefore it was decided to stop

the test at this stage.

The bridge was lifted marginally to insert compensating plates. Another

geodetic levelling stated the final altitude of the bridge deck.

The BRIMOS measurement system was prepared for the night and it was

decided to continue with the tests - starting at 8 o’clock the following

morning.



Measuring system

Additionally to the dense BRIMOS sensor grid the following measurement equipment

was installed at the structure during the day:

• The BRIMOS-Recorder - placed at its new position – above the north-western

column (the one to be cut & lowered).

• The laser-displacement unit in the middle of the bridge’s main span above the

western main girder.

• One Etna-Recorder in the middle of the bridge’s main span (at the western

footpath), one on the eastern footpath.

• The team of the University of Tokyo also arranged their measurement system,

which was distributed stepwise all over the structure.

Fig. 3: Sensor layout – overview - 11th of December in 2008



Fig. 4: Sensor layout – Brimos-Recorder and two ETNA-Recorders – 11th of December

08



Tab. 3: Measurement specification - BRIMOS- & ETNA-Recorders – 11th of December 08

Fig. 5: Sensor layout - BRIMOS sensor grid - 11th of December 08

position [m]

length cross

R1 (BRIREC) 44 6.2 Längs length

Quer cross

Vertikal vertical

E1 (Etna) 29.5 6.2 Längs length

Quer cross

Vertikal vertical

E2 (Etna) 29.5 1 Längs length

Quer crossVertikal vertical




Tab. 4: Measurement specification - BRIMOS sensor grid – 11th of December 08

position [m]

length cross

E105 56 6.2 weiss_laengs length

weiss_quer cross

weiss_vertikal vertical

E204 50 6.2 gruen_laengs length

gruen_quer cross

gruen_vertikal vertical

E210 47 6.2 braun_laengs length

braun_quer crossbraun_vertikal vertical

E103 44 6.2 gelbgruen_laengs length

gelbgruen_quer crossgelbgruen_vertikal vertical

E202 40.8 6.2 schwarz_laengs length

schwarz_quer crossschwarz_vertikal vertical

E201 37.6 6.2 lila_vertikal length

lila_quer cross

lila_vertikal vertical

E205 34.4 6.2 rot_laengs length

rot_quer cross

rot_vertikal vertical

E102 31.2 6.2 gelb_laengs length

gelb_quer cross

gelb_vertikal vertical

E101 28 6.2 blau_laengs length

blau_quer cross

blau_vertikal vertical

E207 28 1 E3_laengs length

E3_quer cross



E6_quer cross



E2_vertikal cross

E2_quer vertical


E5_quer crossE5_vertikal vertical





Laser 28 5 Laser_X cross

Laser_Z vertical

Laser_Z_Glatt vertical-smoothed





Friday 12.12.2008


Temperature: 0°C, partly cloudy, light snowfall during the night, wind velocity 3 m/s

from the west; snow is lying on the structure (this means that the structure’s

temperature is below 0°C)

Damage test lowering of a column:

No settlement of the column during the night, it is still in the elastic region.

No changes were noted



08:00 reinitialization of the measurement system which was running during the

whole night

The laser, the Brimos-Recorder as well as the two Etna-Recorders were set

up again. Identical to the day before the Brimos-Recorder is situated directly

above the column which was cut through, whereas the Etna-Recorders were

situated on both sides midspan.

A levelling was performed.

08:35 Lifting of the column a little bit above the original level, steel plates were

inserted.

A levelling was performed afterwards.

08:49 End of returning the column into its initial position (after the lowering test).

The new level was approx. 6 mm above the original one. A quiet noise caused

by the load distribution was noticed. The cracks at the opposite column are

closed again. This means the reinforced concrete is in successful operation

again. The decisive horizontal cracks move analogue to the deformations.

A levelling was performed afterwards.

12:50 A levelling was performed.

The temperature raised up to 2°C, the snow is melting but remains longer on

the structure itself then in the surrounding area.



Damage test intersecting tendons:

13:10 Start of exposing the cables, which are easy to find by cutting the concrete.

13:43 End of exposing the cables.

The concrete quality is quite good (just as the protection concrete). The

cables are externally undamaged, not rusted and well filled.

13:45 Cutting out of a 10 cm long piece of the first cable. The strands shortened to

2 mm less in length.

No noises were noticed.

Another levelling was made afterwards. A visual inspection was done at the

structure but no cracks or other new indications of damage were found.

In the afternoon a vibrating roller was working next to the bridge (westward)

causing vibrations which were clearly noticeable on the bridge – particularly

after the first cable was cut through.

15:45 The second cable was intersected.

After the second cable was intersected the strands shortened similar to those

of the first one. Single wires were removed to find out whether they corrode

or not. No rust was found. The bridge did not show any indications of

structural changes, cracks etc.

A levelling was done, without any obvious deviation regarding the previous

one.

During the night all 15 sensors of the measurement grid were kept in service

whereas the recorders as well as the laser-based displacement measurement

were removed.

Subsequently to every scheduled step of the experimental campaign a visual inspection

was performed in order to detect possible damage indications. After the first cable was

cut through an extensive inspection was done but no new damages could be found. The

crack formation at the north-eastern column was investigated accurately. Altogether six

cracks in relatively constant distances were observed. After the bridge was returned into



its initial position the cracks were closed again. The distances between the cracks were

measured as follows: 17 + 23 + 30 + 23 + 28 cm.

Conclusions until now:

• The bridge’s manufacturing quality with regard to the used materials is generally

quite good.

• The only apparent defect is the too low reinforced concrete cover (coverage).

• The load bearing capacity seems to be 15% higher than the computed value.

• The structure’s behaviour fully correlates with the expectations, unexpected

effects did not occur.

• Even if the structure was seriously damaged, it still indicated a good, redundand

nature. The analytical investigation predicted local losses (e.g. at the bottom of

the column) which did not occur on site.

• Local damages at the internal prestressing did not induce geodetically confirmed

changes.

• The measurement system had registered all changes and enables an accurate

assessment of changes in the structure’s integrity as well as the load bearing

capacity.

• Bending moments and axial forces related to internal restraint (shrinkage effects

confirmed by frame analysis) were relieved completely due to creeping. No

associated reactions were observed.



Measuring system



• The BRIMOS-Recorder above the north-western column (the one to be cut &

lowered).



• One Etna-Recorder in the middle of the bridge’s main span (at the western

footpath), one on the eastern footpath.


The sensor-layout of the BRIMOS- and ETNA-Recorders as well as the one of

the BRIMOS sensor grid is identical to the one the day before.



Fig. 7: Sensor-layout - BRIMOS- Recorder and two ETNA-Recorder – 12th of December

08




Saturday 13.12.2008


Temperature: - 0.5°C, light snowfall during the night, snow is lying on the bridge, high

fog, no wind

Damage test intersecting tendons:

08:20 The third tendon is cut through. The strands shortened as expected. No

noises or other indications of changing conditions. No cracks or other damage

indication arised at the visual inspection.

08:33 In the signal of the laser a shifting is visible. The middle of the structure has

declined for just a few millimetres (structural rearrangement). That’s why it is

decided to stop doing more severe damages.

To control the values of the levelling it was repeated. The output is consistent

with the day before. The cracks at the eastern pier have not changed since

the day before. This means that there was no torsional movement.

10:15 another levelling was done

10:30 Revealing of the fourth strand and removing of the cement injection. Slight

flash rust on the wires (probably due to the installation); afterwards 5 wires

are intersected. The concerned wires shortened. Six more wires are

intersected.

After that the progressive damage test is stopped.

10:50 Start of removing the measurement equipment.



The visual inspection does not indicate any addidional changes.

Another levelling is done – the result does not differ from the one before.

Demolition of the bridge

19:00 embargo of the motorway and preparing of the demolition

20:00 the bridge is cut through in midspan. As expected that doesn’t cause a

structural collapse.

21:00 The southern part of the bridge was removed with a demolition shear and

two hydraulic breakers. The structure offered a lot of resistance. The tendons

got exposed to a great extent, the wires were visible. There were no obvious

damages or rust at the prestressing. The reinforcement worked as intended

and kept all parts together well. A try to cause a collapse of the southern part

of the bridge failed due to the high redundancy of the bridge. The concrete

quality was equally good at all parts of the bridge. The south-eastern column

was broken off but it did not collapse before most of the concrete was

removed.

After the demolition the condition of several parts of the bridge was

documented.



Measuring system



• The BRIMOS-Recorder above the north-western column (the one to be cut &

lowered) – started at approx. 7:50 am.



• One Etna-Recorder in the middle of the bridge’s main span at the western

footpath (started at approx. 08:00 am), one on the eastern one (started at

approx. 8:10 am).




The sensor-layout of the BRIMOS- and ETNA-Recorders as well as the one of

the BRIMOS sensor grid is identical to the one the day before.

Fig. 10: Sensor layout - BRIMOS- Recorder and two ETNA-Recorder – 13th of December

08




Conclusions:

• Prestressing, concrete quality and reinforcement were in faultless condition

• The system showed an extraordinary redundancy. Even though one column was

removed completely hardly any changes were noticeable.

• The structure showed a great persistence and an excellent behaviour concerning

rearrangement.

• To sum up, sudden failure without any previous indication at a similar structure

of the same quality can be excluded.

The progressive damage campaign established essential knowledge concerning the

assessment of prestressed structures. The structure’s behaviour was better than it was

estimated due to the numerical analysis at all times. First impression into the

measurements indicate, that already very slight artificial damage, induced into the

bridge can be identified and assessed very clearly. Doubts, generally raised with regard

to internally prestressed concrete structures, are unjustifiable in the present case.



Structuring of the recorded data

Due to the huge amount of data they were subdivided into several partial

measurements. Those of the Brimos sensor grid were separated according to the

various damage states – characterised in the measurement description - whereas the

MAINSPAN-measurements in each case contain all the data recorded by one particular

Recorder placed on a precise position of the bridge. Data gaps in the MAINSPAN-

measurements result from the fact that the Recorders were removed during the nights –

unlike the Brimos sensor grid which was constantly measuring from the 10th Dec 08

05:16 PM to the 13th Dec 08 11:14 AM.

measurements with the Brimos sensor grid

S101REIT_081210A_DECK 10.12.2008 05:16 PM 11.12.2008 07:13 AM undamaged structure

S101REIT_081211A_DECK 11.12.2008 07:13 AM 11.12.2008 10:21 AM the north-western column was cut through

S101REIT_081211B_DECK 11.12.2008 10:21 AM 11.12.2008 11:49 AM first step of lowering the column (1cm)

S101REIT_081211C_DECK 11.12.2008 11:49 AM 11.12.2008 01:39 PM second step of lowering the column (2cm)

S101REIT_081211D_DECK 11.12.2008 01:39 PM 11.12.2008 02:45 PM third step of lowering the column (3cm)

S101REIT_081211E_DECK 11.12.2008 02:45 PM 12.12.2008 05:52 AM compensating plates are inserted

S101REIT_081212A_DECK 12.12.2008 08:04 AM 12.12.2008 01:12 PM column returned in original position

S101REIT_081212B_DECK 12.12.2008 01:12 PM 12.12.2008 03:03 PM first tendon intersected

S101REIT_081212C_DECK 12.12.2008 03:03 PM 13.12.2008 05:44 AM second tendon intersected

S101REIT_081213A_DECK 13.12.2008 05:44 AM 13.12.2008 10:08 AM third tendon intersected

S101REIT_081213B_DECK 13.12.2008 10:08 AM 13.12.2008 11:14 AM single wires of the fourth tendon intersected

measurements with the Brimos- and Etna-Recorders

S101REIT_081210A_MAINSPAN 10.12.2008 01:00 PM 10.12.2008 06:02 PMBrimos-Recorder placed in the middle of the

main span

S101REIT_081211A_MAINSPAN 11.12.2008 07:35 AM 13.12.2008 10:50 AMBrimos-Recorder placed above the north-

western column

S101REIT_081211B_MAINSPAN 11.12.2008 08:17 AM 13.12.2008 10:50 AMEtna-Recorder placed in the middle of the main

span at the western footpath

S101REIT_081211C_MAINSPAN 11.12.2008 07:35 AM 13.12.2008 10:56 AMEtna-Recorder placed in the middle of the main

span at the eastern footpath

measurement descripitionmeasurement Start End

Tab. 5: List of all measurements recorded during the progressive damage test from the

10th to the 13th of Dec 08

As the sensors E1, E2, E3, E4, E5 and E6 were recorded by an additional – secondary –

measurement system which is not equipped with a hardware filter an additional

preconditioning of these data is necessary by means of an introductive bandpass-

filtering.

Documents

IRIS FP7-NMP-2007-LARGE-1 D11-1 - VCE · IRIS FP7-NMP-2007-LARGE-1 Iris Demonstration Report – Annex A page 3 of 24 Introduction The flyover S101 is a typical prestressed concrete