Immersed tube tunnelsCoentunnel project

1

Ir. R.W.M.G. Heijmans

Content

• Basic concept• Coentunnel project• Production and installation• Calculations immersed tube tunnel

- Load cases- Models

• Analysis structural integrity 1st Coentunnel• Tunnel equipment

2

Immersed tube tunnels

• Crossing rivers, lakes and estuaries• Places just below river- or seabed• Short landside approaches

3

Immersed tube tunnelDefinitions

4

Immersed tube tunnelJoints

5

Transport

6

Positioning

7

Immersion

8

Placing and coupling

9

Construction joint

10

• Neoprene-steel waterstops

• Shear keys fortransfer of vertical, horizontal and torsion loads

Immersion joint

11

• Gina gaskets for transfer of horizontal loads and first waterproofing• Omega gasket for secondary waterproofing

FoundationSandflowing

12

Ballasting and back filling

13

Project; Coentunnellocation

Existing Coentunnel 12 tubes with 2 traffic lanes

Interfaces

Two tunnels:2 x 2 lanes in one direction3 lanes in the other direction+ 2 tidal flow lanes

Overview

Production of tunnel elements

Traditional casting basin• Tunnel floor and walls/roof

cast separately• Traditional formwork• Tunnel elements can be

curved

19

Casting yard in Barendrecht

Countermoulding of the tunnelfloor

21

Casting yard

22

Casting yardTraditional formwork

23

Early age crack controlHydratation stresses

• Actual stress �0,5 fctm

24

Busan Geoje Fixed LinkCasting yard

25

Busan Geoje Fixed LinkMoving formwork

26

Oresund production facility

27

Production facility OresundFormwork

28

Sea transport route Barendrecht - Amsterdam

OTAOSailing route tunnel elements

Waves:Operational transport criterium:Hsig <= 2.0 mTz <= 4.5 s, Tp = 6.0 sHTE3 <= 0.20 mSurvival conditionsHsig = 3.5 mTz = 7.0 s, Tp = 9.0 sHTE3 = 0.40 m

Bulkheads with pivot supports

Bulkhead supports

32

Concrete bulkhead and Gina gasket

33

Sea transport

2nd CoentunnelTransport phase, Amsterdam locks

Dia 35

Supports of the tunnel elements

Immersion with pontoons

37

Immersion with pontoons

38

OTAOImmersion Tunnel Element 1

OTAOImmersion Tunnel Element 1

Primary support of the tunnel element

41

Secundary supports

Secondary supports

43

Ballast tanks

Ballast tanks

45

OTAOImmersion Tunnel Element 2/3

Immersion process

47

Immersion of Tunnel Element 4

48

Immersion operation

49

FoundationSand flowing

50

• Temporary foundation blocks

• Hydraulic jacks for controlling the vertical position of the element

• Flow pipes cast in theStructure

Sand pancakes

51

Installation gravel bed

52

Scraded gravel bed•Gravel is placed in ridges across the tunnel trench•Vertical accuracy is controlled by a heave compensation system

Gravel bed

53

Concrete wedges

54

Closure joint

55

• Installation of underwater formwork• Sprayed concrete

Sprayed concrete application in closure joint

56

Immersed tube tunnelStructural design

• Bouyancy and uplift stability• Permanent loads:

- Self weight- Water pressure- Earth pressure- Ballast concrete

• Temperature variations• Traffic loads• Special load cases

- Falling anchors- Sinking ships- Shear keys

Bouyancy and uplift stability• Rebar in RC minimum 2,04% 160[kg/m3]• Rebar in RC maximum 2,55% 200[kg/m3]• minimum volume weight concrete 2310 [kg/m3]• maximum volume weight concrete 2382 [kg/m3]• Total volume weight RC minimum 2423 [kg/m3]• Total volume weight RC maximum 2521 [kg/m3] • minimum volume weight water 1000 [kg/m3]• maximum volume weight water 1030 [kg/m3]

• Required SF Bouyancy 1,04• Required SF uplift stability 1,06

58

Floating stability during sea transport

Requirements from Det Norske Veritas:• The metacenter must be at least 1 meter above the buoyancy

point • Up until an angle of 30 degrees a stabilizing moment must be

present

59

Floating stability

60

Floating stability

61

Scale model tests in wave tank

62

Special load cases: Falling anchorsDesign procedure

- Determine the number of ship movements per yearover the tunnel for each ship class, and anchor weight.

- Determine the probability of anchor loss per schips movement

- Determine the probability that a ship is over the tunnel

- Determine the anchor mass based on theacceptable residual risk

Falling anchorsDesign anchor load probability 1E-6

3425

1.E-09

1.E-08

1.E-07

1.E-06

1.E-05

100 1000 10000 100000

Ankermassa [kg]

Ove

rsch

rijdi

ngsk

ans

per j

aar

Cijfers Haven: ankerverlies

RWS-analyse 2005

1.E-06

max. binnenvaartanker: 2500 kg

1

2

3

Falling anchorsValank study

Falling anchorsspread of the load

F

b

2V1 / b

x

y

Special load cases: Sinking shipsLoad modelling of high ships

h e

h k

Ls

�l�Ls

�RLs

qw,e qw,0

h o

R

qg Fl

x

�l�Ls

�FLs

F

Sinking shipsLoad modelling of low ships

x*R

Rtot

R

Sinking shipsLoading zones

zeeschepen binnenvaart binnenvaart

zinkvoeg/sluitvoeg

mootvoeg

Sinking shipsStatistics

• Cumulative probability distribution of sinking ship load

Conclusion:• For seafaring ships an

acceptable risk of 1x10-6equals a load of 122 kN/m2on the tunnel. Dutch guidelines specify 150 kN/m2.

• For barges the maximum loadis 50 kN/m2.

122

1.E-08

1.E-07

1.E-06

1.E-05

1.E-04

1 10 100 1000

Verdeelde belasting q [kN/m2]

Ove

rsch

rijdi

ngsk

ans

1.E-06

150

Shear key loads

Longitudinal behavior of the tunnel

72

• Temperature effects• Differential settlements• Uneven loads

Immersion joint with Gina gaskets

73

Stiffness Gina gasket

74

Soil spring variations

• ROBK guideline:- One sand body missing- Room for interpretation-> variation of

stiffness of 50%• 3D-analysis and beam model

Shear key loadsSand flow pancakes

k

k

��k

k

k

k

k

k

stortmoot 20-25 m

15 m

15 m

k

k

��k

� k

k

k

k

k

stortmoot 20-25 m

15 m

15 m

Loads and section forces

77

Soil spring variations

Damwand op ¾ van de moot.

Damwand op ½ van de moot.

Locatie Belasting Bedding Variant Opmerkingen

Oost West Oost West

Groundcover

1 1 1 1 A11vv

1 1 1 ½ A11vh

1 1 ½ 1 A11hv

1 1 ½ ½ A11hh

¾ ¾

½

½A11hh-driekwart

½ ½ ½ ½ A11hh-half

Water stops

79

Shear key forces

Shear key forcesTAND- EN BLOKKRACHTEN, MAXIMALE BELASTING

van links naar rechts: onderblokkracht, bovenblokkracht, tandkracht

Tand- en blokkrachten max. belasting insteekhaven

-500

500

1500

2500

3500

4500

5500

Tand

1

Tand

2

Tand

3

Tand

4

Tand

1

Tand

2

Tand

3

Tand

4

Tand

1

Tand

2

Tand

3

Tand

4

Krac

ht [k

N]

B11vvB11vhB11hvB11hhB01vhB10hvB10hhB01hh

Tand- en blokkrachten max. belasting vaargeul

-2000

0

2000

4000

6000

8000

10000

Tand

1

Tand

2

Tand

3

Tand

4

Tand

1

Tand

2

Tand

3

Tand

4

Tand

1

Tand

2

Tand

3

Tand

4

Krac

ht [k

N]

G11vvG11vhG11hvG11hhG10hvG01vhG10hhG01hh

Tand- en blokkrachten max. belasting grondaanvulling oevers

-500

500

1500

2500

3500

4500

5500

Tand

1

Tand

2

Tand

3

Tand

4

Tand

1

Tand

2

Tand

3

Tand

4

Tand

1

Tand

2

Tand

3

Tand

4

Krac

ht [k

N]

A11vvA11vhA11hvA11hhA11hh-1/2A11hh-3/4

Shear key forces

1 m

�V

Shear key load in a 2D framework calculation is thedifference in shear force DV over one meter of the 3D model

Framework calculation

Framework calculationsRounding off of bending moments

Design of the shear keys

• Bearing pressure• Longitudinal reinforcement

• Pressure in thediagonal

• Confinement of thediagonal

• Combination ofcompression and bending

Prestressing of the tunnel element

86

Prestressing

• Influence factors- Length tunnel

element- Point loads

bulkheads- Curvature tunnel

element- Waves - Location support

jacks- Distribution ballast

tanks

87

Roughened face of TE for increased friction

88

Loading situation in floating condition

89

Floating tunnel elements

Prestressing

91

Operational conditionWave: Hs = 2 m T = 6 sec

Survival conditionWave: Hs = 3 m T = 9 sec

Prestressing

92

Design for fire loadsCFD-calculations

93

Design for fire loadsRWS-fire curve

94

T-rebar < 250 °CelsiusT-concrete < 380 °Celcius

Design for fire loads

95

Temperature gradients in the structure with heat resistent cladding

Fire test

96

1st Coentunnel integrity + separation-wall

Cross-section

Loading and boundary conditions

Severe scenario’s

• Realistic approach (PLAXIS-calculations)• Worst-case approach

Scenario calculations

• Results:- Displacements- Bending moments and shear

forces

- Input for 3D-model

Deformations?

u1 u2

Star-lichaamsverplaatsing

90 m

�u30

u1 u2

Kromming

90 m

�u30

Rigid body motion Curvature

3D-model 30 m

• Damage assessment- Current situation (normal crack-pattern)- Add. WC-forces (no additional cracks…)- …and diamond cases (damage)

• Robustness assessment- Damage boundaries

Incomplete foundation

Immersion joints

Gina

Roof

Shear key (ring-shaped dowel)

Floor

Immersion joints

�q xy = ½Vy

�� = ½Vy

druk trek

�q xy = ½Vy

�� = ½Vy

Dw arskracht

Contactspanningen ringdeuvel

ø12

ø16

ø19

ø28

Vfailure: 2800-3400 kNVreal.: 600-1200 kNVworst case: 3570 kN

Large cracks expected before reinforcement activation. gasket will not function anymore.

Immersion joints

�q xy = ½Vy

�� = ½Vy

druk trek

�q xy = ½Vy

�� = ½Vy

Dw arskracht

Contactspanningen ringdeuvel

ø12

ø16

ø19

ø28

Vfailure: 2800-3400 kNVreal.: 600-1200 kNVworst case: 3570 kN

Large cracks expected before reinforcement activation.

gasket will not function anymore.

�q xy = ½Vy

�� = ½Vy

druk trek

�q xy = ½Vy

�� = ½Vy

Dw arskracht

Contactspanningen ringdeuvel

ø12

ø16

ø19

ø28

Vfailure: 2800-3400 kNVreal.: 600-1200 kNVworst case: 3570 kN

Large cracks expected before reinforcement activation.

gasket will not function anymore.

Immersion joints

Concluding…

• Robustness analysis points out:- Robustness calculated in DIANA agrees with RWS risk

diamond- No significant damage in tunnel parts due to worst case

scenario’s- Immersion joints and closure joint are weak parts due to

possible shear failure, which leads to water inflow.

Typical cross section with separation wall

110

Separation wall

111

• Tubes are screwed in• Tubes have Larssen interlock

connections• The void on the in- and

outside is filled with grout

Plaxis FEM calculation

112

Free water surface around a sailing ship

113

Bed level – attenuated bow and stern wave pressure gradients

Stern wave gradient zone Bow wave gradient zoneLowered steady pressure

Attenuated pressure (dhs)Pressure change zone length (Ls)

Attenuated pressure (dhf)Pressure change zone length (Lf)

Zone for stern wave slope Lss Zone for bow wave slope Lfs

2nd CoentunnelCurrent effect on separation wall

114

Return flow

Tunnel Technische Installations:

• MTM(traffic management)• Power supply• Lighting• Drainage• Ventilation• Fire suppression• Communication

115

Traffic management system

• Motor vehicle Traffic Management (MTM)(Verkeersmanagement)- Automatic signalling based on traffic image- Traffic lights and matrix indicator panels- Height detection- CCTV camera observation:

- Speed control- Traffic control- Smoke detection

116

Traffic systems

• Traffic control• Optimizing traffic flow• Detection of accidents• Control during calamities

117

Electrical power supply

• low voltage distribution device

118

Tunnel lighting

• Entrance lighting• purpose:

- Prevent black hole effect - Traffic safety

119

Drainage pumps & pump sumps

• Goal:- To prevent aquaplaning at rainfall- Safe disposal of liquid fuel 4m2/min

120

Drainage system precipitation curves

121

Regenkrommen volgens Braak

0

20

40

60

80

0 20 40 60 80 100 120 140 160 180 200Tijdsduur t [min]

Nee

rsla

g N

[mm

]2 jaar

5 jaar

10 jaar

50 jaar

250 jaar

Drainage system

122

Effective area of pump sump:150 m2Pump capacity: 50 l/s

Tunnelventilation & over-pressure installation escape gallery

123

- Longitudinal ventilation with jet fans- over-pressure ventilation of escape gallery and

staircases- Escape doors to the central gallery every 100

meter- Purpose:

- Traffic emission- Reduction of NOx, CO, Benzene centration- Maintain visibility

- Smoke control during fire:- Smoke free evacuation of passengers- Smoke free access of emergency services

Ventilation, clusters of jet fans

124

Escape doors

• Designed:• 1 hour @ 1100-1350 °C• Hydrocarbon fire

125

Firefighting

126

Communication, Control & transmission

- Communication- Intercom in emergency cabinets- HF radio antenne- Load speakers- Pictograms for excape routes

- SCADA, (central) control systems & transmission

- PLC’s, copper of glass fibre connections in the tunnel, service buildings and traffic control center

127

for your attention.

the result …

128

…. and thanks

Imagine