aiea workshop 12-16 december construction · pdf fileisolate the motion of the superstructure...

Présentation Nuvia Travaux SpéciauxIAEA Workshop 12-16 December 2011 – Construction Technologies

EARTHQUAKE-PROOF PADS OF JHR ProjectAIEA WORKSHOP 12-16 DECEMBERCONSTRUCTION TECHNOLOGIES for Nuclear Power Plants: a comprehensive approach

Le Groupe NuviaThe Jules Horowitz Reactor 1Présentation de SalvaremThe seismic base isolation choice 2ActivitésASB qualification 3Gamme de produitsASB manufacturing 4Exemples de projetsImplementation on site 5

IAEA Workshop December 2011 – Construction Technologies 2

IAEA Workshop December 2011 – Construction Technologies

• Jules Horowitz Reactor (JHR) key figuresMain data Eighen frequency of rigid str. : 9 Hz

Eighen frequency of isolated str. : 0,60 Hz

PGA : 0,35g (hard soil conditions)

195 elastomeric bearings

Bearings dimensions : 900 x 900 x 120 mm

Damping ratio : 5%

Dynamic shear modulus : Gd = 1,10 MPa

1Jules Horowitz Reactor (JHR)

4


• JHR seismic base concept

1

5

Jules Horowitz Reactor JHR elastomeric bearings special bearing plates with:

- Connectors (studs)

- Removal stops

- Non shrinkable removable mortar

assembled sandwich delivered on site (removable mortar for replacement operations casted) commissioning (adjustment and settlement with concrete)


Springs with horizontal stiffness K

KM2T

Building mass M

• Principle of seismic isolation Isolate the motion of the superstructure from the motion of the

ground by using flexible horizontal isolators (ASB).

• Consequences Increase and shift the natural period from the high frequency range

of the earthquakes (reduce the amount of energy transferred to the structure).

Reduce significantly the acceleration and thus the shear forces induced by the earthquakes in the structure (F = m x A).

21. Seismic base isolation concept

7


• Sandwich made of metal & elastomeric rubber

• Metal: metallic steel plates S235 prepared

• Elastomeric rubber: raw elastomeric matrix (compound) composed of : Elastomeric polychloropren (CR)

Additives

Plasticizers

Activators

Protection agent

Vulcanizer agent

Accelarators

• Vulcanization = temperature + pressure

CH2 C

Cl

CH CH2

polychloropren

CH2 C

Cl

CH CH2=

chloropren

==

2. Isolator (ASB) 2

8


• ELASTOMERIC BEARINGS MAIN FEATURES Major components

- Rubber layers: provide lateral flexibility- Steel plates: provide vertical stiffness to support building weight while limiting lateral buckling of rubber

Typical hysteresis loop

22. Isolator (ASB)

9


• ELASTOMERIC BEARINGS MAIN FEATURES Behavior

- Each elementary layer, subject to stresses and movements, deflects as shown in the three diagrams below:

- Elastomeric bearings are assimilated to spring and damper associated in parallel.

22. Isolator behavior

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• Limitation of the horizontal acceleration Behavior on a single mode (around 90% of the mass) corresponding to the Eigen frequency of the isolation

0.01

0.1

1

0.1 1 10 100>9 Hz

0.7 g0.3 g

Sans appuis

>9 Hz

0.7 g0.3 g

Sans appuis

0.6 Hz

0.12 gAvec appuis

0.6 Hz

0.12 gAvec appuis

23. Main benefit

11

without ASB

with ASB


• Uniform acceleration (rigid body) Limitation of the deformation

Force decreased on the civil structure and on pipes supports

Floor spectra equivalent on each level i.e. design simplified

Strong robustness regarding safety and protection of the investment

23. Main benefit

12

0.12g

0.12g

0.12g

0.12g


1. Why qualification is needed?• Approach focused on the following main objectives:

Validate the input data from engineering code by experimental approach to use actual values for the design

Improve the production of the elastomeric bearings up to a high quality level in compliance with the requirements of the “Order of August 10-1984” (French Republic “arrêté du 10 Août 1984”) and in general IAEA Safety Requirements GS-R-3

« Industrialize » the installation of the bearings on site by special working procedures implemented on full scale mock-up

Improve the robustness of the laminated rubber bearings:- improve real margin- validate assumptions (ageing effect)

3


• Test plan with parametric studies (> 1000 tests at Chalon, Bochüm, Pavie & Vitry testing labs) during 2006-2008 in collaboration with French Safety authorities and CEA (French Nuclear Agency)

• Mechanical properties variation studies (stiffness, damping) versus: Solicitation parameters: frequency, distortion, creeping

Size of the sample: full scale test and samples (even sample location)

Ageing: accelerated ageing (18 months equivalent to 70 years)

52. Isolator qualification

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• Tests are realized either on reduced-scaled samples, or on full scaled samples (depending on the laboratory capability)

• A reduced factor (β’) is used for compression tests on reduced scaled samples.

• The following tests are done: Compression tests (static & dynamic)

Shear tests (static & dynamic)

Creep tests

Shear adhesion tests

)b'(a'2t'b'a'β'

3

16

2. Isolator qualification


• Samples water jet cutting

33. Tests on samples

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INTERNAL SPECIAL TESTING BED FOR SAMPLES

(Dynamic shear test)

Actuator: +/- 150 kN +/- 50 mm +/-20 mm à 3 Hz

Vertical jack: 100 kN 55 mm

Samples to be tested

• Samples testing bed

33. Tests on samples

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• Compression tests (static & dynamic) : Kvs, Kvd, ξ

F

Specimen

Displacementpick-up

Press plates

ωt.sin FFF a0 ΔdΔFK d 2

ddc Δd.K.π

w2.ξ

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

-120 -100 -80 -60 -40 -20 0 20 40 60 80 100 12

34. Tests on full-scale ASB

19

0

2000

4000

6000

8000

10000

12000

14000

0 0.5 1 1.5 2 2.5SETTLEMENT (mm)

CO

MPR

ESSI

ON

LO

AD

(KN


• Shear tests (static & dynamic) : Khs, Khd, ξ

3

20

ES10/111 - ABS ITER N°16108 & 16107

0

200

400

600

800

1000

1200

1400

1600

1800

0 20 40 60 80 100 120HORIZONTAL DISPLACEMENT (mm)

HO

RIZ

ON

TAL

LOA

D (K

N

ASB n° 16109 : +/- 110 mm under 0.55 Hz

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

-120 -100 -80 -60 -40 -20 0 20 40 60 80 100 120

Horizontal displacements [mm]

Horiz

onta

l loa

ds [k

N]

TdAp

²'

G d pw

2ds

4. Tests on full-scale ASB


5. Materials durability• Durability of elastomeric bearings is a concern because:

Nuclear facilities’ life duration is long (70 years)

Mechanical properties of rubber change over time

• Tests are performed in laboratory to predict these evolutions Principles are based on Arrhenius law

Treatment method in standard ISO 11346

Temperature speeds up physical and chemical changes (ageing phenomena)

90°C4,75 months

80°C9,5 months

70°C19 months

60°C38 months

50°C6,25 years

40°C12,5 years

30°C25 years

20°C50 years

T°CAging

Laboratory conditions

Van’t Hoff law:Ageing divided by 2 when T°C increases by 10°C

3

21


ΔG/G0

G = Shear Modulus

Time in hours

• Principle of the tests Ageing phenomenon affects chemical and mechanical properties of the rubber.

Key parameter of the experimentation : the shear modulus G i.e. the tracer

Knowing the evolution of G, we can deduce the evolution of the ASB behavior

Tests performed on both samples and full scale ASB

• Description of aging tests (Arrhenius model) Regular measurements of the shear modulus G

on pieces of rubber exposed to various T°C

For a variation of X% in the shear modulus value,

we note the corresponding time for each isotherm.

35. Materials durability

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• Description of ageing tests (Arrhenius model) Combinations (t / T°C) are plotted on a graph log (t) = f(1/T).

If the accelerated ageing follows the Arrhenius model, all points should line up.

The slope of the Arrhenius line is proportional to the activation energy of the physico-chemical reaction E (J/mol).

35. Materials durability

23


Context

• Installation requirements Flatness tolerances : < 0,1% (i.e. < 1.1mm/m)

Void ratio criteria under steel plate : < 5% (i.e. < 6.05 dm²)

+ =Grouted bearing

(supporting 567 T)Concrete plinth

C40/50

13001300

Elastomeric bearing + plates S355 (1,5 T)

1100 1100

3• Installation on site

24

6. Implementation on site qualification (mock-up)


36. Implementation on site qualification (mock-up)

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Elastomeric Vulcanizing agent

Plasticizer Adds

Mixing

Raw materials mixed

Confection

Vulcanizing

Plates preparation

Plates Bonding agent

Plates prepared

Finishing Works

Calendaring

Protection

41. Industrial process - Manufacturing

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• Important process points are identified and checked at each steps and are part of the QA process: Follow-up documents filled Tests performed (rheology on mixture, mechanical properties of mixture samples…) Measurements (thickness, mass, pressure and temperature of the press…) Monitoring (thermal gage inside each bearing)

2. Industrial process - QA & QC on factory 4

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3. Industrial process - Production tests 4• Production test on bearings :

Tests performed in Eucentre (Pavia) and Freyssinet Testing labs Static tests (compression and shear tests) Additional dynamic tests (compression and shear tests)

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4. Industrial process - QA/QC on bearing plates 4• Important process points are :

Follow-up documents filled Measurements (thickness, rectitude, coating…) Tests on the welds of the connectors (traction and bending) On-shop assembly

32


1. Assembly in workshop 5

34

• In workshop: Monolithic sandwich assembly (same height) Injection of a mortar (removable layer for replacement operations) Tests on mortar (rheology, compression) Follow-up documents filled


2. On-site commissioning 5

35

• Operations performed on site Concrete sandblasting of the plinths for concrete stop Sandwich adjustment to pier Settlement of the connector with self-compacting concrete Final settlement using special method

• Controls Seat of the plate Properties of the mortar and concrete (rheology and resistance) Follow-up documents filled


5• Jules Horowitz Reactor (JHR) seismic base isolation under construction

36

2. On-site commissioning


• International Thermonuclear Experimental Reactor (ITER)

Installation of bearings under progress

5

37

3. Other seismic base isolation


• International Thermonuclear Experimental Reactor (ITER)

Installation of bearings under progress

5

38

3. Other seismic base isolation


CONCLUSION

• APPLICATION OF ASB TO SEISMIC VULNERABLE STRUCTURES : Preserves structures from damages Maintains functionality of buildings (even during earthquake) Reduces the costs of the Project in terms of design and construction Protects the value of building contents (greater than structure itself)

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Présentation Nuvia Travaux SpéciauxIAEA Workshop 12-16 December 2011 – Construction Technologies

New Build & Decommissioning Department

Sébastien DIAZ

92 cours Vitton69006 Lyon

[email protected]

+33 (0)4 72 14 44 90

+33 (0)4 72 14 45 09

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aiea workshop 12-16 december construction · pdf fileisolate the motion of the superstructure...

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