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MAIN PROJECT DATA

- 17.064 m long hydraulic tunnel

- 1 double shield TBM having a boring

diameter of 4,88 m

- 4,2 m internal section

- Excavation will be associated with hexagonal precast segments lining

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LINING OF HEXAGONAL PRECAST SEGMENTS

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The method with double shield + hexagonal segments

has been adopted by SELI in many other completed projects, namely:

The Yindaruquin irrigation project China (18 km)

The Evinos aqueduct project Greece (30 km)The Guadiaro aqueduct project Spain (12 km)

The Whanjazhai Yellow River Diversion Project China (90 km)

The Esperanza-Poza Honda project Ecuador (23 km)The Mohale project Lesotho (30 km)

The Pieve Vergonte water power project Italy (9 km)

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It is now applied in the following projects under

construction:

The La Joya water projectCostarica (9 km)

The Dez-Ghomrud water tunnel projectIran (18 km)

The MonteGiglio ground

conveyance project Italy

(9 km)

The Kerman LongTerm water supply

project Iran (65 km)

The Gigel Gibe - Omohydroelectric power project

Ethiopia (28 km)

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THE TUNNELING SYSTEMGENERAL DESCRIPTION

The System is composed of:

A double shield TBM having a boringdiameter of 4,88 m

A back up system for this TBM The rolling stock to muck out, to transport

material and personnel

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The system is able to execute the tunnel in a single pass operation, including the following works:

- Excavation of tunnel

- Erection of precast lining- Backfill grouting of annular space between the

excavation and the precast lining

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The principal improvements of proposed doubleshield are:

the cutterhead design

the exploration drilling rock consolidation measures

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PRELIMINARY TUNNEL TYPICAL SECTION

- Boring diameter: 4,88 m

- Outer dia. of the segmental lining: 4,70 m

- Inner dia. of the segmental lining: 4,20 m

- Segmental lining tickness: 25 cm

- Longitudinal lenght: 1,30 m

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TBM DS Excavation cycle of double shield

STEP 1:STARTING

STEP 2:

TUNNEL EXCAVATION AND INSTALLATION OF

SEGMENT

STEP 3:

ADVANCING THEGRIPPER SHIELD

(REGRIPPING)

STEP 4:

BACK UP ADVANCE

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Back - up

The main targets at the base of its design development have been: shortest possible length of the back-up without compromise on

capacity, efficiency and completeness

reduced time for back-up assembly and connection to the TBM

physical separation, inside the tunnel section, of the back-upequipment & working area from the rail track transport line

provide all along the tunnel a safe walkway and working space onthe side of the transport train

reduced overall weight and dimensions of the back up decks for more economic packing and transport

to be fully in respect with safety standards and CE certified

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The back up main components are:

hydraulic power units

main power transformers

ZED system

operator control cabin

electric switchboard

Variable speedfrequency converters

TBM auxiliary equipment General Services

fresh air ventilationand air distributionsystem

train pusher segments unloadingand trasport system

pea gravel system

grouting system

gas monitoring

air scrubbing system

compressor

emergency gen set

MV cable and reels

lighting system

close circuit TVcamera system

muck conveyors

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Rolling stock

Conveyor

Equipment

Walkway foroperators

SECTION

PLAN VIEW

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Rolling Stock

Each tunnel train includes:

10 muck cars with acapacity of 10 m 3 each

1 pea gravel car

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4 flatbed cars for the transport of precast segments

1 personnel car

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MAIN AUXILIARY EQUIPMENT AND SYSTEM

Ventilation system and dust control Gas detection and alarm system Tunnel ground water pumping system

Electric power supply Industrial water line Compressed air system

Lighting system Telephone system

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VENTILATION SCHEME ON TBM AND

BACK UP AREA

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MONITORING OF THE TBM PARAMETERS AND

TUNNEL INSTRUMENTATIONSA data-taker registers on electronic support thefollowing parameters:

- Total thrust- Total power - Working torque- ZED readings- Cutterhead RPM- Penetration rate- Stroke

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MONITORING OF THE TBM PARAMETERSAND TUNNEL INSTRUMENTATIONS

Moreover it could be recorded:

- Duration of each 65 cm stroke- Altitude and position of the TBM relative to the tunnel

axis- Pressure distribution in the thrust cylinders- Cause and duration of any advance stoppage

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PRELIMINARY ORGANIZATION OF

TUNNELLING ACTIVITIES

maintenance + eventual probe drilling

boring shift 1

boring shift 2

10 h 10 h4 h

per 6 days/week

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TBM to advance in unstable ground: cavity filling

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TBM to advance in unstable ground: front consolidation

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