Intervenant - date

Institut français des sciences et technologies des transports, de l’aménagement et des réseaux

SHM trends and opportunities for civil engineering EWSHM2014

Nantes, July 11, 2014

Frédéric Bourquin, Director, COSYS department,

Bruno Godart, Deputy head, MAST department …

Intervenant - date

The vast Field of Civil Engineering

• A vital sector for the Economy (Mobility of human and goods, Water ressources and treatment, Protection against various natural Hazards, Urban development,…)

• A strategic sector for the Energy (e.g. nuclear power plants, off-shore platforms, NGL reservoirs,…)

• A strategic sector for the Army Infrastructures…

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Structures exposed to various actions

• Constantly exposed to aggressive environments (deicing salts, sea water, frost, sulfatic soils, acid water, etc.)

• Exposed to the aging of their equipements and their constitutive materials

• Exposed to the deteriorations of their elements due to increasing utilization (traffic and loads, abrasion, …) and human actions (fires, vehicules impacts, vandalism, explosions,…)

Impact of heavy truck

on the pier

of A11 bridge,

June 1997

Mathilde Bridge fire,

Rouen, Oct 2012

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Water-borne disasters

Scour consequences Pile failures due to torrential flood

Inundation

and

submersion

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Network operation disruption

Landslides

Floods

Structural

failures

(Minnesota,

I-35W - 2007)

Earthquakes

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Networks and cities

Road Congestion (France) City Pollution (China)

Train

derailment

(Spain)

Failure

of water PC

pipe (USA)

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Some challenges for monitoring…

• A Safety priority: some structures are subjected to severe disorders and even collapses…

• A societal demand for more and more availability of the infrastructures (zero interruption !...)

• A heavy and costly investment for the society, that is not easy to replace

• A long lasting patrimony requiring a management policy : thorough inventory, inspection, repair, strengthening, adaptation to new needs,…

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Some challenges for monitoring…

• Appropriate procedures and methods to ensure

– The ultimate load capacity of structures

– The Serviceability

– The Durability and Reliability

– The Availability

• Structural Health Monitoring (SHM) is a key Issue for the management of CE Structures

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The SHM: Main Objectives of surveillance

• The surveillance of structures by Monitoring may have several objectives : – confirm or check the conclusions of a diagnosis

– detect malfunctions

– have a better understanding of the behaviour of a structure

– anticipate its natural ageing

– optimize the maintenance actions

– prevent failures or collapse.

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The SHM: 4 Different levels of surveillance

• There is a progressivity in the SHM which is adapted to each individual structure and to the problem to be treated and which is depending on the available means:

• The Intermittent survey: it is intended to collect at each point of measurement the studied parameters via the intervention of an operator on site (Measurement of distance between studs, fissurometer,… - frequency 1/week or 1/month): – For relatively low speed of deterioration

– Low cost and very little maintenance

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The intermittent survey

Distancemeter with

invar wire 3D Fissurometer (Saugnac type)

Crack

measurement

with a

translucent

fissurometer

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The SHM: 4 Different levels of surveillance

• The temporary surveillance: installation of an instrumentation with automatic data acquisition for a rather short period (several weeks):

– Temporary survey of a structure to confirm a diagnosis (measurements of the activity of cracks,…

– Monitoring of the structure during works made in its vicinity (stability, settlements,…)

– Investigations for a diagnosis (monitoring of the sag under loading, study of the fatigue, vibration analysis,…)

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Temporary surveillance

Gauge J1

Day of measure Stress range (Mpa)

Example of the Cheviré Bridge:

Fatigue histogram on 18 days

Gauges

glued on

steel

Raw measures under traffic

Number

of

cycles

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The SHM: 4 Different levels of surveillance

• The intensified surveillance: to follow closely the evolution of a defective or a doubtful structure, during a rather long period of time (more than one year)

– most often to detect an abnormal evolution

– for better identifying the causes of the disorders and better understanding its behaviour,

– to check the effectiveness of a repair

Intervenant - date

Intensified surveillance

Tancarville Bridge (France)

0

5

10

15

20

25

30

35

40

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

1995 1996 1997 1998

Cum

ula

tive

num

bre

of f

ailu

res

Upstream suspension

Downstream suspension

Evolution of the number of wire failures recorded during the acoustic

monitoring of the cables of the Tancarville suspension bridge by

LCPC, from august 1995 to march 1998.

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Intensified surveillance

The case of the Cheviré bridge (1988 – 1991) ; Length = 1563 m

The main span consists of a steel orthotropic box girder (L = 162 m)

resting on two prestressed concrete cantilevers (each length 40 m).

Each cantilever is having a high deflection due to creep…

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Intensified surveillance

Evolution of the deflection at the end of the cantilever (in cm)

Difficulty to model the creep…. Is there an asymptote ?

-30

-25

-20

-15

-10

-5

0

1990 1993 1995 1998 2001 2004 2006 2009 2012

Def

lect

ion

(cm

)

Time

BPEL E= 36 GPa

Eurocode 2

E = 26 GPa

Eurocode 2

E = 26 GPa + LCPC

Creep tests on cores

times 1.7

Measures with

inclinometers

?

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Intensified surveillance

The case of the Salanfe dam -

Length 617 m – Height 52 m

A gravity dam damaged by alkali-

aggregate reaction

Irreversible upstream movement has

currently reached 35 mm

at crest level

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Intensified surveillance

Necessity to have a FEM model fitted to the measurements

(displacements and pendulum) to assess the condition of the dam and

then used to model the effects of several sawings in the upper part.

-50

-45

-40

-35

-30

-25

-20

-15

-10

-5

0

0 20 40 60 80

Do

wn

str

eam

d

isp

. (m

m)

Time (years)

Block 23 (set 1)Block 13 (set 1)Block 23 (monitor)Block 13 (monitor)Block 23 (set 3)Block 13 (set 3)Block 23 (set 2)Block 13 (set 2)

Displacement of the crest (measures and model)

Model of a cut

Direct pendulum

Intervenant - date

The SHM: 4 Different levels of surveillance

• The safety surveillance: consists in following the evolution of one or more physical variables, preferably measurable, and in applying previously defined safety instructions as soon as these physical variables reach a threshold allowing to characterize a dangerous situation. It necessitates: – a thorough analysis of the phenomena likely to occur and

allowing a reasonable evaluation of the corresponding risks (risk analysis) ;

– an establishment of precise instructions that must be strictly applied when required. For bridges, this set of instructions must include the instructions for the management of the traffic when the thresholds are exceeded.

• It is applied for a short duration, the time to design and implement a repair solution...

Intervenant - date

Safety surveillance

Variation of the opening of a flexure crack in a PC bridge deck

as a function of the thermal gradient

Alarm curve

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SHM: the Monitoring of new Structures

• Often applied on strategical structures (Dams, Nuclear Power Plants, Large Bridges,…)

Rion-Antirion bridge (Greece)

Design Loads:

-- Earthquake with a return period of 2000 yrs or 5% possibility of exceedance in 120 yrs

-- Techtonic movements up to 2 m between adjacent mains pylons

-- Wind speeds ut to 260 km/h and Ship collision of 180000t DWT

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SHM: the continuous Monitoring of Structures

• Monitoring of the Rion Antirion bridge by Advitam: – Load Cells and Accelerometers on Stay Cables – Strain gages on the gussets of the lower anchorages of the stays) – Forces in the transverse retaining devices of the deck – Accelerometers on the pylon head, on the deck, at the pier base

and on the ground – Movement of the expansion joints – Detection of the presence of water in the Pier Base – Temperature in the pavement – Meteo Station on the deck about 300 sensors

Complementary to visual inspection and NDT ; Based on risk analysis…

Intervenant - date

Opportunities (continued)

• SHM as an operation-critical technology (obvious Return on Investment)

Control of construction processes

Zero maintenance railway tracks

scour detection coupling AVM+structural analysis

5th generation, energy positive road

• Scalability : prefab, satellite (istimes), TDR, nanotechs

• Big data opportunities

Intervenant - date

Tunnelling : increase productivity and safety

Early detection of preconvergence and extrusion

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Leader:

New Ballastless Tracks Project Zero maintenance makes SHM

operation critical

FUI Project

The new solution is deployed between

Gisors and Cerqueux 5 years after starting

from scratch

Highly scalable Optical Fiber continuous strain monitoring

works

Complex fatigue thermal testing at IFSTTAR confirms

the performance

Intervenant - date

Scour detection by actual change of the structural behavior : combine the best of FEA and AVM

FB, G. Hovhanessian, E. Merliot,G. Rodovalho

Intervenant - date

Focus on effects not on scouring phenomenon Perturbation analysis (inverse eigensensitivity)

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Scour detection= AVM+Structural engineering

Assessment of pile stiffness against overturning

2nd order perturbation yields computable range

of stiffness variation where « 1.8 » is valid

Peyrehorade bridge

AVM

Structural analysis

Intervenant - date

On-line displacement variation for the design load (hydrostatic pressure…) or vice-versa : level 4

Structural

analysis

« SME »

Precomputes

u and w

Off-line On-line

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5RG overarching concept - Forever-open road

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Concept of the Gaia Snow-Melting System (Japan)

heated track (France, Siemens, Ifsttar)

Bast (Germany) heated road

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Scalability perspectives

• Prefabrication

• Nanotech-based sensing elements suited to low-cost fabrication and deployment process

• Satellite + airborne + ground based

• TDR

Intervenant - date

Taking advantage of PREFABRICATION DECID2 PROJECT – Large Dimensions Plateform made of Smart Composite

with Double-SHM (M. DRISSI-HABTI et al.)

Smart Polymer-Matrix Composites : Lightweight, Corrosion-Resistant Materials that Contain Embedded Sensors

Partners : ETPO, CETIM, IDIL, IXFIBER, DFC, SYNERVIA, IFSTTAR, LARMAUR (Rennes1), GeM

PI IFSTTAR (M. DRISSI-HABTI, monssef.drissi-habti@ifsttar.fr) Support from 2 competitiveness clusters : EMC2 and PGCE Funding : Ministry of Industry, PAYS DE LA LOIRE, BRETAGNE, PICARDIE Total Budget : 3.8 M€ funding : 2.3 M€ 2 Platforms 20m x 3.5m

Intervenant - date

DECID2 SMART COMPOSITE PLATFORM (Lightweight, Corrosion-Resistant Materials that Contain Embedded Sensors )

(IFSTTAR, Contact: monssef.drissi-habti@ifsttar.fr)

Specimen for Fatigue Testing

That Contains Embedded

Optical Fiber Sensor Ultrasonic Patchs That

were Embedded

Intervenant - date VTTI Workshop on Smart and Resilient Infrastructure 16 -17 APRIL 2 0 1 2

Long term perspective:

Massively distributed sensing elements

The « smart aggregate » concept,

Ultrasonic sensors based on CNT membranes : B. Lebental et al.

Sensing element

Energy source

Communication

device

Computing

capability

Intervenant - date

10/07/2014

IFSTTAR Nantes Al electrodes

Sensitive composite

Asphalt

Piezoresistivity of C/sep-MWNTs over asphalt

patent ( 01/04/2014)

Load monitoring from asphalt :

graphene/sepiolite/MWNTs B. Lebental, B. Ghaddab, V. Gaudefroy, E. Ruiz, P. Aranda, C.Ruiz, B. Hennings

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Istimes E.M. sensing: part of GMES KeTs V. Cuomo, F. Soldovieri, J. Dumoulin et al.

Intervenant - date

HIGH RESOLUTION SAR DATA Processing

The new generation of

high-resolution SAR

sensors, such

as TerraSAR-X (TSX)

and the COSMO-

SkyMed constellation,

allows the systematic

acquisition of data

with spatial resolution

reaching

metric/submetric

values.

25 TerraSAR-X Spotlight acquisitions (15 months) Azimuth resolution: 1.1m

Slant Range resolution: 0.6 m

cm/y

22

-2

Las Vegas monorail. optical view compared with deformation mean “velocity”

Award as the 2011 best paper published in IEEE Geoscience and Remote Sensing Letters

Intervenant - date

LOW-COST scalable TDR (ECT) for health monitoring of External post-tensioned ducts (F. Taillade et al.)

Inside the bridge

Ducts

Duct: High Density PolyEthylene

Steel Cables Strand

Cement grout injected

Intervenant - date

TDR Health Monitoring

t

Defect zone

TDR

t

Defect zone

TDR

Assuming the tapes are perfect conductors, the distributed electric impedance of the

line depends on the material filling.

Cable monitoring by electrical Time Domain Reflectometry + inverse modelling

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TDR method: results on Labéraudie bridge

Presence (observed) of void and white paste

Post-tensioned duct + electrical tape

0 5 10 15 20 25 30 35 400

5

10

15

20

25

30

35

40

x (m)

eff

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A few big data opportunities

• Big players (Telecom, utilities…) may foster massively distributed sensing

• towards linearizing the damage detection problem via

special purpose observers

relaxation of constitutive laws

• HPC on chip + Reduced Order Modelling

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Sensor placement via FE analogy

Load identification =

Finite Element approximation of a non-local problem

over the «sensor mesh»:

sensor placement formulated as mesh adaptation

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Messages

• SHM for civil structures plays a crucial role for the economy

• Consider SHM as a special case of a wider activity

smart cities and territories

connected objects, internet of everything

• Develop disruptive service-oriented sensors (+computing)

operating over wide areas

with metrological quality

that also work for SHM!

Intervenant - date

Monitoring at urban scale http://www.parisest-sense-city.org/

Intervenant - date

Acknowledgement

The authors wish to thank F. Soldovieri (IREA, Napoli) and colleagues from Istimes project G. Hovhanessian (Advitam), G. Rodovalho (Advitam), F. Taillade (EDF), R. Lauriot di Prevost and M. Tisseau (SIEMENS SAS / Infrastructure & Cities), Véronique Le Corvec (NECS) B. Lebental, F. Derkx, V. Gaudefroy, B. Ghaddab, E. Ruiz, P. Aranda, C.Ruiz, B.

Hennings, M. Drissi-Habti, J. Dumoulin, E. Merliot, J. Waeytens, M. Smail, Y. Gueguen, L-M. Cottineau, Th. Sedran, V. Le Cam, X. Chapeleau … (IFSTTAR)

Thank you for your attention

Intervenant - date

Thank you for your attention

www.ifsttar.fr

Intervenant - date

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Aknowledgments

• The authors thank for their contribution :

– F. Soldovieri (IREA, Napoli),

– G. Hovhanessian and G. Rodovalho (Advitam),

– F. Taillade (EDF, previously at IFSTTAR),

– M. Drissi-Habti, J. Dumoulin, B. Lebental, B. Ghadab, E. Merliot, J. Waeytens, M. Smail, Y. Gueguen, R. Kuate, L-M. Cottineau, V. Le Cam, D. Siegert, A. Orcesi, P. Marchand, A. Khadour (IFSTTAR)

Intervenant - date

Galileo Galilei

Misura ciò che è misurabile, e rendi misurabile ciò che non lo è

Intervenant - date

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Porticoes: SSI yields defects

Ambiant vibration monitoring at IFSTTAR Nantes (D.Siegert & Advitam)

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Frequency as a robust damage indicator

Added mass 70kg

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exploiting the best of FES

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Intervenant - date VTTI Workshop on Smart and Resilient Infrastructure 16 -17 APRIL 2 0 1 2

Smart instrumentation of a motorway section : A10 Cofiroute

One example of R5G Demonstrator

Intervenant - date

Aim : tune and assess design and building methodologies a new generation of railway track on concrete slab

Suitable for low-speed freight and high-speed passenger transport

enabling more daily traffic due to highly reduced maintenance

reliability and durability of the infrastructure : lifetime >100 years

High speed track laying > that of a ballasted track (1km/day)

reduced costs of track laying

Leader:

New Ballastless Tracks project : Zero maintenance makes SHM

operation critical

FUI Project

Intervenant - date

thin concrete slab track + fast construction process + integrated health Monitoring (Brillouin OFS)

the market for high-speed track on concrete slab

The market in Europe focuses on Germany, Spain and France,

it is around 200 km of rail per year

expected market in China: thousands of kms

low maintenance costs

Leader:

New Ballastless Tracks

FUI Project

The new solution is NBT project Today, the reference solution system Rheda 2000

Intervenant - date

Decoupling inverse algorithms from FES damage detection via inverse modelling

J. Waeytens, V. Le Corvec, M. Smail, FB

Structural analysis SME :

Here NECS uses ASTER

Inverse algo as a Python

supervisor

Intervenant - date

BADIFOPS Project = Use of Ultra High Performance Concrete instrumented by Optical Fibers for earthquake-resistant applications

Transfer of strains from the host medium towards the fiber without any concrete cover effects

Existing Solutions:

Iten M. “Novel applications of distributed fiber optic sensing in geotechnical engineering” PhD dissertation

ETH-Zürich 2011.

Leng JS et al., Sensors and Actuators A-PHYSICAL, 2006 126(2) 340-347.

Intervenant - date

> Originalité des travaux réalisé dans le cadre du projet BADIFOPS

- The fibers are monomod SMF-28 (with a primary coating). Fibre optique

Barre d’acier

Transfer des déformations

- Localization of embedded fibers in a recess (trench)

Polyimide Elasticity modulus (MPa) 2400 Resistance (traction) (MPa) 130 Temperature of functioning -65°C à +300°C Coefficient of thermal expansion 0.5×10-6 /K à 20 °C Resistance to statical fatigue Yes Chemical Durability Bad Mechanical Protection Very bad Transmissibility of deformations Excellent

- The glue between the bar and the primary coating

Fiber

Glue

Steel