D2011 Project

CEA-IRSN Results

Alain MILLARD, Frédéric DELERUYELLE

Gyeongju, Korea, April 20-23, 2009

Task A - STEPS 0/1

Contents

• Step 0 – New theoretical model– Drying test results

• Step 1– Hypothesis– Preliminary results

• Conclusion

Step 0

• Model used previously :

– Pg = Patm

– No vapor diffusion (Richard’s approximation)

– Intrinsic permeability :

– Relative permeability :

– Adopted values : K0 = 2. 10-20 m2 λ’ = 0.68

0

03

2

2

3

0

1

1

KK

SSk llrl

'1

'

11

2

Drying test

ResultsK0 = 2.0 10-20 m2, Hr = 33%

Water content profiles

Change in mass with time

New theoretical model

Total water mass balance : 0)(

WWtm

vlw

Liquid mass flux : pSkTKW llrll

wl )(

)(

Constant gaz pressure hypothesis : pg = patm

Vapor mass flux : pDSTRΜW vvag

vv

Vapor pressure :

TRMpTpp

l

vcvsv exp)(

pDTDW lvpvTv =>

New theoretical model

scmDTT

pp

D vag

atmva /,217.0 2

0

88.1

Vapor diffusivity in air :

New adopted values : K0 = 1. 10-19 m2 λ’ = 0.4

New resultsK0 = 1.0 10-19 m2, Hr = 33%

Water content profiles

Change in mass with time

Step 1 – VE Experiment Phases 0,1

0102030405060708090

100

RH

[%

]

Applied RH

Mean of the RH of tunnelsensorsRH of outcoming air

Section SA3

In flow

RH-out

Water pan 1SA1

SB1 SC1SA2 SD1 SE

SC2 SB2SD2 SA4

SA3

Rear doors

Out flow

RH-outRH-in RH-1 RH-2

Water Pan 2

RH-in

Instrum ented section:SA : M in i P ie zo m e tersSB : H um id ity se ns orsSC : T D RsSD : Exten so m e te rsSE : G e oe le ctric

Forward doors

Legend :

R H-n : hyg ro m e te rRH-rRH-l

10 m

7 m

1,50 m

1,00 m

0,65 m

0,65 m

0,60 m

0,60 m

0,60 m

0,60 m

1,00 m

0,65 m

0,65 m

1,50 m

Phase 1

Step 1 – Hypothesis

• 2D plane strain model• Isotropic properties• Isotropic in-situ stresses• Constant temperature T=15°C• Same models and properties as for Step 0 • Influence of boundary conditions in tunnel• Phases 0 and 1 : calculation over 2120 days

Mesh

130 m

Initial and boundary conditions

σ = -3.2MPa, Pl = 1.21MPa

Pl = Hr (t)

or exchange

U . n = 0

Φl . n = 0

σ (0) and Pl (0)

affine in z

Sl (0) = 1

φ (0) = 0.16

Hr(t) in the tunnel

prescribed

Mean in SA3

Mean in tunnel

Exchange bc in the tunnel

► Inside the tunnel : nq hhext

rr)(

► Identification of α on the mean evaporated water mass

from the water pans :

● From 08/09/2003 to 28/01/2004 : Δm = 686.5 g

● Use of mean hrext

(t) in SA3 => α = 7.143 10-6 Kg/m2/s

-6000

-5000

-4000

-3000

-2000

-1000

0

18/0

7/02

03/0

2/03

22/0

8/03

09/0

3/04

25/0

9/04

13/0

4/05

30/1

0/05

18/0

5/06

04/1

2/06

Time [days from VE start]

Wat

er lo

st in

eac

h p

an [

gra

ms]

0

10

20

30

40

50

60

70

80

90

100WaterPan-1WaterPan-2

Base case

• No vapor diffusion

• K0 = 2. 10-20 m2 λ’ = 0.68

• Prescribed mean hr in the tunnel

• E = 6000 MPa

Extracted water masskg

Relative humidity – SB1

0,67 m

0,90 m

1,00 m

1,15 m

1.40 m

Relative humidity – SB2

Relative displacement – SD1mm

Relative displacement – SD2mm

Water pressure kPa

Initial water pressure

-1000

-800

-600

-400

-200

0

200

400

600

800

1000

0.65 1.15 1.65 2.15 2.65

Distance from MT center [m]

pw

[k

Pa

]

28/07/2002 (horizontal)

28/07/2002 (45º)

28/07/2002 (vertical)

2 MPa

-12 MPa

0.

Variant 1

• Vapor diffusion accounted for

• K0 = 1. 10-19 m2 λ’ = 0.4

• Prescribed mean Hr in the tunnel

• E = 6000 MPa

Extracted water mass

Relative humidity – SB1

Relative humidity – SB2

Relative displacement – SD1

Relative displacement – SD2

Water pressure

Variant 2

• Vapor diffusion accounted for

• K0 = 1. 10-19 m2 λ’ = 0.4

• Exchange boundary condition in the tunnel• E = 1000 MPa

Extracted water mass

Relative humidity – SB1

Relative humidity – SB2

Relative displacement – SD1

Relative displacement – SD2

Water pressure

Conclusions

• Step 0 :– Accounting for vapor diffusion in a simplified way– Results similar to other teams

• Step 1 : – Preliminary results– Best results using vapor diffusion and exchange

condition– Over-estimated extracted water mass– Reduced rock stiffness

Thank you for your attention