INTERNATIONAL SEMINARLONG TUNNELS

17, 18 y 19 de Octubre 2012Santiago, Chile

LOGISTICA, UN ASPECTO CRITICO EN LA CONSTRUCCIÓNDE TUNELES DE GRAN LONGITUD

LOGISTICS, A CRITICAL ASPECT IN THE CONSTRUCTION OFLONG TUNNELS

Matthias Neuenschwander, MSc ETHZ

Desafío para el Diseño, Construcción y Operación

Challenges for Design, Construction and Operation

PIARC CHILE

PRESENTATION OUTLINE

1. What is so crucial about logistics in longtunnels?

2. Why the Gotthard base tunnel as anexample?

3. How do logistics influence on time andcost?

1. Excavation2. Concreting3. Muck handling4. Water and mud

4. When do we start thinking about logistics?

5. Conclusions

6. Who takes the risk?The importance of fair contracts

Logistics in long tunnels, five base lines1. Long tunnels require the right excavation system and good

logistics.

2. Long tunnel sites are vulnerable because there is noalternative supply line (nor an alternative discharge line).

(Corollary: the more faces you have, the less vulnerable you are.)

3. Time is money means: in order to be faster in constructionyou must invest in equipment (and keep it working).

(Corollary: DO NOT try to save on equipment.)

4. The relation between the tunnel site and it’s equipment islike a marriage: based on the best intentions only, struck atan early stage, very expensive to change.

5. Logistics above ground are as important as thoseunderground.

Logistics as a risk factor

The consideration given to the subject in theGotthard Hole-through risk analysis

The Gotthard Base Tunnel (Switzerland)

Mountain areaLong accesswaysTunnel lengths comparable to trans-andeantunnels

The Gotthard Base Tunnel, Bodio sectorA few numbers:TBM Excavation from 7.1.2003 to 26.10.2006Overall tunnel length: 15’970 m (East), 15’650(West), 1’200m (Cross adits), total: 32’820 m

Item Total Per meterExcavation (cum) 2’036’000 62 (=168 ton)Concrete (cum/tons) 581’445 17.8 (=44 ton)Water pipes (m) 124’000 4Cable ducts (m) 753’000 23Provisional rail track (km) 135Provisional water and air ducts (km) 130Electrical energy (MWh) 201’200 6.2Mud treatment (tons) 293’000Water treatment (cum) 6’600’000Cooling water (closed circuit) >500 cum/h)

Gotthard Base Tunnel: D&B excavation

Estimated production rates according toexcavation classes: 0.5 m/day – 8 m/day(Sedrun sector)

0.001.002.003.004.005.006.007.008.009.00

10.00

SPV

AK I

SPV

AK II

SPV

AK II

Ia

SPV

AK II

Ib

SPV

AK IV

Mec

h. A

K IV

SPV

AK V

Mec

h. A

K V

SPV

AK V

Ia

Mec

h. A

K V

Ia

Mec

h. A

K V

Ib

Mec

h. A

K V

II

Production rates (m/d), D&B Sedrun sector contract

The Gotthard Base Tunnel: TBM excavation

Real production rates (m/month), Bodio east heading

Unexpectedfault

Unexpectedsqueezingzone

Bodio muck handling: rail system

Layout: 22 muck trains per day per tunnel, for atotal of max. 2’800 km of transportation/day

Muck handling in the GBT: recycling

From tunnel face to destination: on conveyorbelt or train and barge. Road transportationreduced to a minimum.

Concrete according to geological situation

TBM tunnel and D&B tunnel, extreme cases

Concrete: from the plant to the face, 32 km

Layout:- Sprayed concrete: 150 cum/d = 10 rotations/day- Cast concrete: 750 cum/day = 20 rotations/day- Maximum transportation distance: 30x64 = 1’900 km

Water and mud handling: who wouldhave thought what a hassle this is?Mud sources:- Water discharge (treatment plant)- Concrete works- Tunnel cleaning- Concrete gravel production plant (not shown on graph)

Tunnel mud production, Bodio and Faido sites (ton/month)

Water and mud handling: who wouldhave thought what a hassle this is?The Bodio water treatment plant

The earlier we think about it...

Typical evolution of degree of projectdefinition and of cost in a construction project

Conclusions

- Logistics hardly ever is ano-go item in a tunnelproject, but:

- Good logistics are notvisible on a site

- Bad logistics are extremelycostly and time consuming

- Logistics need to bedesigned as all else, fromthe first stages of a project

- Logistics are a key factor tosuccess of long and deeptunnels (and most others)

Who takes the risk?

About the importance of fair contracts

- Distinct pricing for equipment- Correct allocation of construction time risk- Formula for time related cost