Auxiliary measures applied in the tunnel construction of

Auxiliary measures applied in the tunnel construction of the Jonica motorway

Kolloquium Bauhilfsmassnahmen im Tunnelbau

ETH Zürich

Salvatore Lieto (ASTALDI S.p.A.)Paolo Perazzelli (ETH Zurich)

Project overview

Outline

Tunnel construction problems and design changes

Conclusions

Project overview

Taranto

Reggio Calabria

Jonica motorway (490 km)

Old motorway

Project overview

New motorway

Completed Sections

Launched

Assigned andnot launchedIn design

Taranto

Reggio Calabria

Project overview

Completed Sections

Launched

Assigned andnot launchedIn design

Taranto

Reggio Calabria

ASTALDI S.p.A. as General Contractor

Section 3 (Sibari - Roseto Capo Spulico)

Section 2 (Squillace - Simeri Crichi)

Section 1 (Gerace - Marina di Gioiosa Jonica )

Project overview

“Strada extraurbana principale – Cat. B (D.M. 5 novembre 2001) ”

Two-lane dual carriageway (lane width 3.75 m)

Velocity: 70 - 120 km/h

Total length 11.3 km

Project overview

Two-tube tunnelsn° 5; l = 2.6 km

Viaductsn° 7; l = 2.5 km

Two-tube cut-and-cover tunnelsn°7; l = 1.1 km

GERACE TRIGONI TIMPA PERGOLA LIMBIA

Costs of the project = 354 Ml €

3.753.75 9.75 m

1.750.5

I = 30-35 m

total length of the tunnels (L = 5.2 km)

H>2B

H = 4.5 m – 75 m

35% 35% 30%

2B>H>B H<B

ground surfacewater table

11.9 m

B

9.4 m

Project overview

Pl Monte Narbone formation (gravelly sand)

Ap Trubi formation (silty clay, clayey silt)

Pl 25%

Low

erP

leis

toce

neU

pper

Plio

cene

Sp Trubi formation (clayey sandy silt)

Hol

ocen

e

Qt Quaternary deposits (superficial deposits)

5% 20%

Ap

Qt

Pl

total length of the tunnels (L = 5.2 km)

Pl Ap

75%

Sp

z [m]

Project overview

Project overview

Outline


Conclusions


Limbia Tunnel Carr. NordL = 385 m

Pl (gravelly sand)

considered section

0

120 m

40

80

GravelSand

6040

0% 50% 100%Granulometry

0% 50% 100%granulometry

relative density Dr = 40 - 80% friction angle ’ = 30°– 45°DR=100%

DR=80%

0

100

200

300

400

500

6000 10 20 30 40 50 60 70 80

' v (k

Pa)

NSPT

Limbia

AS36

Limbia 1

’ v[k

Pa]

20 40 600600

400

200

0

NSPT

Dr [%] =10080

800

10

20

30

40

50

60

70

80

90

0,0 0,5 1,0 1,5 2,0 2,5 3,0 3,5 4,0 4,5 5,0

N S

PT

(kg/cm2)

Limbia

AS36

5002500 ’v [kPa]

80

40

20

0

60

NS

PT

3025

4540

35

cohesion c’ = 0


Pl : Monte Narbone formation (gravelly sand)


jet grouting columnsreinforcedwith fiberglass bolts

drainage24 m

drainage

1418

9

0.6 m 0.67

13.8 15.4

9.7

10.3 m

1.25

A

A

B

B

A-A B-B(after exc.)

0.72

C

C

C-C

1.5 m

0.4 m

0.8 m

shotcrete and steel ribs

length of round= 0.75 m Installation every 9 m of advance

jet grouting columnsreinforcedwith steel pipes


In situ jet grouting tests

Mono fluid systemColumn [-] 1 3 5 7 2 4 6 8

Design diameter [m]

Column [-] 1 3 5 7 2 4 6 8

Grout pressure [MPa] 40 40 35 35 40 40 35 35

Number of nozzles [-] 2 2 2 2 2 2 2 2

Nozzle Diameter [mm] 2.4 2.4 2.4 2.4 2.4 2.4 2.4 2.4

W-C ratio by weight [-] 1 1 1 1 1 1 1 1

Grout flow rate par nozzle [l/min] 57 57 53 53 143 119 155 133

Injected grout volume per unit length [l/m] 380 333 442 398 108 90 117 100

Average lifting speed of the monitor [mm/s] 5 5.7 4 4.5 13.3 16.0 11.5 13.3

Observed diameter [m] 0.85 - 0.95 0.44 - 0.5 0.39 - 0.48 0.62 - 0.71 0.55 - 0.65

0.8 0.4

0.75 - 0.85


9 m

5 m

10.3 m

10.3 m

9 m


9 m

9 m

5 m

10.3 m

10.3 m

0

0.5

1

1.5

2

0 5'000 10'000 15'000 20'000 25'000

adva

nce

rate

[m/d

ay]

costs [€/m]

original design



Limbia Tunnel Carr. NordL = 385 m

new design

advance rate = 0.25 m/day

Pl (gravelly sand)

0

120 m

40

80


10 m

4

1.212 m

A

A

A-A

1.25

drainage

jet grouting columns15-35 m



4

1.2

14.3

A

A

B

B

A-A

B-BC-C

CC

A B

A B

1.25

15-35 m

0.9 m

1 m

1.2 m

10 m

12 m

drainage

jet grouting columns



Dt =1.2 m1.2Lt = 2.1 m

Dm =1.04 m Lm =2.03 m

0.9

Dm =1.06 m Lm =2.07 m Dm =1.25 m Lm =2.15 m

Injected grout volume per unit length

Average lifting speedof the monitor

733 l/m 800 l/m 933 l/m

7.3 mm/s 6.7 mm/s 5.7 mm/s

4.5 m

0.5 m

Mono fluid system

Observed

Design values Dt =1.2 m1.2 Lt = 2.1 m Dt =1.2 m

1.2Lt = 2.1 m

0.9 0.9

Grout pressure 40 MPa

Number of nozzles 2

Nozzle Diameter 4 mm

W-C ratio by weight 1

Grout flow rate par nozzle 160 l/min



Grout pressure 40 MPa

Number of nozzles 2

Nozzle Diameter 4 mm

W-C ratio by weight 1

Grout flow rate par nozzle 160 l/min

Injected grout volume per unit length 969 l/m

Average lifting speed of the monitor 5.5 mm/s

Mono fluid system Design values

Dt =1.2 m Lt = 2.1 m

Dm =1.04 m Lm =2.03 m

0.9

Dm =1.06 m Lm =2.07 m Dm =1.25 m Lm =2.15 m

Injected grout volume per unit length

Average lifting speedof the monitor

733 l/m 800 l/m 933 l/m

7.3 mm/s 6.7 mm/s 5.7 mm/s

4.5 m

0.5 m

Observed

Design values Dt =1.2 m Lt = 2.1 m Dt =1.2 m1.2Lt = 2.1 m

0.9 0.9

1.2 1.2



12 m 12 m

12 m 12 m


0

0.5

1

1.5

2

0 5'000 10'000 15'000 20'000 25'000

adva

nce

rate

[m/d

ay]

costs [€/m]

new design

original design



Trigoni Tunnel Carr. SudL = 880 m

considered section

0

120 m

4080

Ap (silty clay)


SandSiltClay

0102030405060

0 20 40 60 80 100

plas

ticity

inde

x(%

)

limit liquid (%)

CH

MHOH

MLOL

CL-ML

CL

’ [°]30 4020

30

60

90

0

c’ [kPa]


Ap Trubi formation (silty clay, clayey silt)


16 18 m

12

9.8 m

1.25

12

A

A

B

B

A-A B-B (after exc.)


length of round = 0.75 m concrete invert

fiberglass bolts

grouted steel forepolings

60-110 fiberglass bolts(density 0.5 - 0.9 bolts/m2)

48 steel forepolings(spacing 0.4 m)

installation every 12 m of advance


surface fractures induced by the excavation

excavation faces

0.2 m

0monitoring stations in a distance of 24 m from the tunnel face

design threshold

uv

uh1+uh2 uh1 uh2

uv

re-profiling of the tunnel section inorder to guarantee the minimumclearance profile

0.0

0.5

1.0

1.5

2.0

0 5'000 10'000 15'000 20'000 25'000

adva

nce

rate

[m/d

ay]

costs [€/m]

original design



Trigoni Tunnel Carr. SudL = 880 m

new design


0

120 m

4080

Ap (silty clay)


A

A

CC 24 m

A-A

C-C

11 m

12-16 m

2.5 m

1.35 m1.5 m

1.35 m

1.5 m

13.7 m


length of round = 1 m concrete invert bored piles of lean concrete

bored piles of lean concrete


bottom of the bored piles

0.2 m

0monitoring stations in a distance of 24 m from the tunnel face

new design

tunnel convergences strongly reduced

uh1+uh2

uvuv

uh1 uh2

0.0

0.5

1.0

1.5

2.0

0 5'000 10'000 15'000 20'000 25'000

adva

nce

rate

[m/d

ay]

costs [€/m]

new design

original design



Gerace Tunnel Carr. NordL = 553 m

0

H = 4 – 6 mAp (clayey silt)Sp (clayey sandy silt)

considered sections

120 m

40

80


SandSiltClay

’ [°]30 4020

30

60

90

0

c’ [kPa]


SandSiltClay

’ [°]30 4020

30

60

90

0

c’ [kPa]


Ap Trubi formation (clayey silt)

Sp Trubi formation (clayey sandy silt)


16 18 m

12

9.8 m

1.25

12

A

A

B

B

A-A B-B (after exc.)


concrete invert

fiberglass bolts

grouted steel forepolings

60-110 fiberglass bolts(density 0.5 - 0.9 bolts/m2)

48 steel forepolings(spacing 0.2-0.4 m)

installation every 12 m of advance

length of round = 0.75 m


Face instability

0.0

0.5

1.0

1.5

2.0

0 5'000 10'000 15'000 20'000 25'000

adva

nce

rate

[m/d

ay]

costs [€/m]

original design



Gerace Tunnel Carr. NordL = 553 m

H = 4 – 6 mAp (clayey silt)Sp (clayey sandy silt)

new design


0

120 m

40

80


1.25

24-36 m

length of round = 1 m

14 m

21.5

3.1

15.2

groundsurface

lean concrete

9.8 m

A

A

A-A


Steel reinf. 6 15x15

concrete invert


Carr. Sud Carr. Nord

0.0

0.5

1.0

1.5

2.0

0 5'000 10'000 15'000 20'000 25'000

adva

nce

rate

[m/d

ay]

costs [€/m]

new design

original design


Conclusions

Contractual obligations (construction time and costs) & uncertainties in the design phase

flexibility in the execution phase

Documents

Auxiliary measures applied in the tunnel construction of