INTRODUCTION TO

IMMERSED TUBE TUNNEL TECHNOLOGY

BY

ABHAY OCEAN INDIA PVT LTD

� BACKGROUND

� TRADITIONALLY LARGE (SEA) CROSSINGS CARRIED OUT BY MEANS OF THEAPPARENT MOST ECONOMIC OPTION –BRIDGE.

� IF A TUNNEL OPTION IS CONSIDERED - BORED TUNNEL SEEMS FAVOURITE .

� IN RECENT PAST NEW DEVELOPMENTS AND INNOVATIONS HAVE LEAD TOREVIVAL OF IMMERSED TUNNEL AS A COMPETITIVE ALTERNATIVE FOR LARGEFIXED LINKS .

� THE ØRESUND LINK BETWEEN DENMARK AND SWEDEN GAVE THE IMMERSEDTUNNEL TECHNIQUE THE FIRST BOOST.

� THIS WAS FOLLOWED BY OTHER MAJOR LINKS IN WHICH IMMERSED TUNNELTECHNIQUE IS APPLIED ON LARGE SCALE.

� THE LAST IMPRESSIVE EXAMPLE IS THE FEHMERNBELT LINK, THE LINKBETWEEN DENMARK AND GERMANY COMPRISING AN IMMERSED TUNNEL OFALMOST 19 KM.

MAJOR SEA CROSSING ØRESUND LINK BETWEEN DENMARK AND SWEDEN

INTRODUCTION TO IMMERSED TUNNELS

� AN ALTERNATIVE TO BRIDGES AND BORED TUNNELS .

� IMMERSED TUBE TUNNEL UNITS OF LENGTH OF ABOUT 100M LONG,

FORMING COMPLETE TUNNEL CROSS-SECTIONS WITH BOTH ENDS

TEMPORARILY SEALED BY A BULKHEAD ARE FABRICATED IN A DRY DOCK.

TUNNEL ELEMENTS IN CASTING BASIN (ANTWERP TUNNEL ELEMENTS FLOODED CASTING BASIN

SEALED UNITS ARE FLOATED AND TOWED TO TUNNEL LOCATION AND LOWERED INTO

A PRE- DREDGED TRENCH IN THE SEA OR RIVER BED

OFF SHORE TRANSPORT TUNNEL ELEMENTS OF PIET HEINTUNNEL (THE NETHERLANDS)

TUNNEL ELEMENT AT PROJECT LOCATION TUNNEL ELEMENT DURING IMMERSION

TOWING & IMMERSION OF TUNNEL ELEMENTS

� AN ALTERNATIVE TO BRIDGES AND BORED TUNNELS.

� IMMERSED TUBE TUNNEL UNITS OF LENGTH OF ABOUT 100M LONG, FORMING COMPLETE

TUNNEL CROSS-SECTIONS WITH BOTH ENDS TEMPORARILY SEALED BY A BULKHEAD ARE

FABRICATED IN A DRY DOCK.

� SEALED UNITS ARE FLOATED AND TOWED TO TUNNEL LOCATION AND LOWERED INTO A PRE

DREDGED TRENCH IN THE SEA OR RIVER BED.

� ON ONE END OF EACH TUNNEL ELEMENT, AN ENDLESS GINA GASKET IS MOUNTED.

� UPON TUNNEL UNIT BEING IMMERSED, IT IS THEN PULLED FIRMLY UP AGAINST THE

PRECEDING IMMERSED TUNNEL UNIT WITH A HYDRAULIC JACK.

� WHEN THE GINA GASKET HAS FULL CONTACT AROUND THE TOTAL CIRCUMFERENCE OF THE

ADJACENT TUNNEL UNIT, THE WATER BETWEEN THE BULKHEADS IS PUMPED OUT.

� DUE TO THE PRESSURE DIFFERENCE BETWEEN THE BULKHEADS AND THE HYDROSTATIC

PRESSURE ON THE OUTSIDE OF THE TUNNEL, THE GINA PROFILE COMPRESSES AND SEALS

THE JOINT. THE UNITS WILL THEN FORM A CONTINUOUS TUBE AND THE TRENCH IS

BACKFILLED PROGRESSIVELY.

IMMERSED TUBE TUNNEL

�WHAT IS AN IMMERSED TUNNEL

�PRECAST TUNNEL ELEMENTS,

CONSTRUCTED IN THE DRY.

�FLOATED TO THE DESTINATION.

�LOWERED INTO PLACE, JOINED AND

COVERED UP.

�HISTORY

�FIRST CONSTRUCTED ABOUT 120 YEARS AGO.

� ABOUT 200 HAVE BEEN CONSTRUCTED ALL

OVER THE WORLD.

� ABOUT 150 ARE FOR ROAD OR RAIL.

� FIRST PROPOSED 1860 Harlem River Tunnel, New York 1911

�TUNNEL CROSS SECTIONS

�Selection of cross-sections determined by local experience and practice.

�In the U.S.A. use of steel shell tunnels is more common .

�In Europe and Japan reinforced concrete tunnels are more popular .

�Structure of steel shell tunnel is of relatively thin-walled composite steel and

concrete rings.

� There are a wide range of cross-sectional configurations, depending on

intended use of the tunnel.

�Circular-shape section, binocular and rectangular shape section are used for

immersed tube tunnels.

�The trench is then backfilled and any necessary protection, such as Rock Armor,

added over the top .

�The ground beside each end tunnel element is reinforced, to permit a tunnel

boring machine to drill the final links to the portals on land.

�After these stages the tunnel is complete, and the internal fit out can be carried

out.

�LAND-SIDE INTERFACES

�VENTILATION BUILDINGS

�EARTHQUAKE JOINTS

�CUT-AND-COVER TUNNEL

�OPEN APPROACHES

�SEQUENCE IMT-C&C SCHEDULE

DRIVEN

�IMMERSED TUNNEL CHALLENGES

�Use Advanced Construction

Techniques.

�Use Latest Ventilation Techniques.

�Select ideal Immersed Tunnel

Alignments.

�Determine Construction and

Staging Locations.

�Deal with Difficult Ground

Conditions.

�Dredging and Disposal.

�The Gina gasket and Omega seal are used between the sectional elements

of immersed tunnels to prevent water ingress due to external water

pressure.

�The combination of seals allows for sealing, for the transfer of the

hydrostatic loads and movements between the tunnel ends due to soil

settlement, creep of concrete, temperature effects and if required

earthquakes The designs are generally based on the expected tunnel

lifetime of 100 years. Pressure difference between the bulkheads and the

hydrostatic pressure on the outside of the tunnel, the Gina profile

compresses and seals the joint.

�GINA GASKETS

FINAL PLACEMENT OF IMMERSED TUBE ELEMENTS

� Immersed tunnel elements floated to site using their buoyant state.

� Ends of tunnel elements equipped with bulkheads (dam plates) across

ends to keep inside dry.

� Bulkheads located to allow only about 1.0 m between the bulkheads of

adjacent elements at immersion joint.

� This space is emptied once an initial seal is obtained during the joining

process.

� Joints usually equipped with gaskets to create seal with the adjacent

element.

� Adjustment devices allow placement of the elements on line and grade.

� Tunnel elements lowered into their location after adding temporary water

ballast in designated water ballast tank.

� After installation of back fill, ballast water is exchanged with ballast

concrete, installed on the tunnel base slab.

� Subsequently finishing of tunnel and tunnel installations place.

TUNNEL CROSS SECTION

� SELECTION OF TYPICAL CROSS-SECTIONS IS DETERMINED BY LOCAL

EXPERIENCE AND PRACTICE .

� IN THE U.S.A. USE OF STEEL SHELL TUNNELS ARE MORE COMMON.

� IN THE EUROPE AND JAPAN REINFORCED CONCRETE TUNNELS ARE MORE

POPULAR CONCRETE TUNNEL.

STEEL TUNNELS

SINGLE SHELL

DOUBLE SHELL

SANDWICH TUNNEL – RECENT DEVELOPMENT IN JAPAN

� Both internal &external structures are Steel plates.

� Internal steel diaphragms, Connect plates.

� No reinforcement.

� Filled with non shrink self compacting concrete.

DOUBLE SHELL TUNNELS

WHY AND WHEN ARE IMMERSED TUNNELS COMPETITIVE / ADVANTAGES

� Immersed tunnels have advantage over bored tunnels for water crossing locations .

� They lie only a short distance below water bed level. Approaches are therefore relatively shorter .

� Compared with high level bridges or bored tunnels, the overall length of crossing will be shorter.

FLEXIBILITY IN CROSS SECTION SHAPES

IMMERSED TUNNELSPOSSIBLE CROSS SECTION SHAPES -

OTHER ADVANTAGES OF IMMERSED TUNNELS

� MAIN ADVANTAGE IS THEY CAN BE CONSIDERABLY MORE COST EFFECTIVE THAN

BORED TUNNEL BENEATH THE WATER OR A BRIDGE

� OTHER ADVANTAGES RELATIVE TO THESE ALTERNATIVES INCLUDE:

� SPEED OF CONSTRUCTION

� MINIMAL DISRUPTION TO RIVER/CHANNEL, IF CROSSING A SHIPPING ROUTE

� RESISTANCE TO SEISMIC ACTIVITY

� SAFETY OF CONSTRUCTION (WORK IN A DRY DOCK AS OPPOSED TO BORING

BENEATH A RIVER)

� DREDGED MATERIAL CAN BE USED MAKING ARTIFICIAL ISLANDS / LAND

RECLAMATION

� DISADVANTAGES ARE:

� DIRECT CONTACT WITH WATER - CAREFUL WATERPROOFING DESIGN AROUND

JOINTS

� THE SEGMENTAL APPROACH REQUIRES CAREFUL DESIGN OF THE CONNECTIONS

� ENVIRONMENTAL IMPACT OF TUBE AND UNDERWATER EMBANKMENT ON

EXISTING CHANNEL / SEA BED.

ILLUSTRATIVE EXAMPLES - IMMERSED TUNNEL PROJECTS

�The Øresund Link - First major sea crossing using immersed tunnel technique and

bridge connection between Denmark and Sweden.

�16.7 km link is Road and train carriageway

� The transition between the tunnel and the bridge is accommodated by a large

artificial island approx 4 km long

� At the Denmark shore a significant land reclamation extending 430 m in the sea was

established. Øresund Link (aerial view)

THE ORESUND LINK…. CONTD

�Immersed part of the tunnel length - 3500 m

�Tunnel is divided into 20 elements, each 176m long; each element is made up

of 8 segments of 22m each

�The tunnel includes two railway tubes, two motorway tubes and an escape

gallery

�Outer dimensions of the cross section are 8.5m by 41.7 m.

Cross section immersed tunnel

Busan Geoje Crossing, South Korea

� Road connection in south eastern part of South Korea between Busan and Geoje.

� Link comprises of two cable stayed bridges and a concrete immersed tube tunnel

�Tube Tunnel comprises of 18 tunnel elements with a length of 180m each

� Immersed tunnel is 3.2 km long and deepest (max water depth of 48 m) in world

INSTALLATION OF BUSAN GEOJE TUNNEL ELEMENTS

HONGKONG ZHUHAI MACAO LINK, CHINA�A challenging infrastructure project - HZBM Link under construction

�Main project is offshore section of HZMB Link of approx. 30km, crossing the Pearl River

Estuary from border with Hong Kong to Macao and Zhuhai (Mainland China).

�Link comprises various bridges, artificial islands and tunnels to accommodate a dual

carriageway with 3 traffic lanes in each direction.

�Crossing of main shipping channels at the eastern side of the Pearl River Estuary will be

realised using a 6.75km long tunnel, of which 6km will be immersed.

�Transition from bridges to tunnel will be by artificial islands with a length of 625m each.

ISLANDS DESIGN FOR HONGKONG ZHUHAI MACAO LINK

ILLUSTRATIONS ARTIFICIAL ISLANDS AND TUNNEL ENTRANCE (ON ISLAND

�In HZMB Link transition between bridges and the immersed tunnel will be

realized by artificial islands.

�The islands are approximately 625 m long and 160 m wide.

�Technical service buildings for the tunnel are located at the islands

FEHMERNBELT LINK, DENMARK

�Fehmernbelt Fixed Link planned to cross the Fehmernbelt between Rødbyhavn,

140km south of Copenhagen, and Puttgarden, on the north coast of Germany

�Comprehensive studies including environmental studies resulted in decision

that immersed tunnel is best solution

�Project combines records such as a length of 18.5 km and a water depth of 30

m, while crossing a busy navigational channel.

IMMERSED TUNNEL SOLUTION - FOR FEHMERNBELT LINK, DENMARK

�Tunnel elements consist of combined road and rail cross-section all at one

level within concrete structure

�Each Standard element of immersed tunnel has length of approximately

217 m.

�Underneath the road and rail tubes there will be access to all areas of the

tunnel to reduce disruption of the traffic to a minimum.

IMMERSED TUBE TUNNEL CONSTRUCTION IN HONG KONG

1: Cross Harbour Tunnel. 2: Mass Transit Railway Tunnel.

3: Eastern Harbour Crossing Tunnel. 4:Airport Railway Western Immersed tube

5: Western Harbour Crossing Tunnel. Tunnel.

•Hong Kong has extensive immersed tube tunnel experience

•First steel immersed tube tunnel was placed across the Victoria Harbour in

1972.

•There are four other vehicle/railway tunnels crossing the Harbour using

immersed tube techniques.

•The layout plan of the five immersed tube tunnels is shown in the Figure

below

�OUTFITTING SITE

�Finish elements

�Ready them for immersion

�Attach elements to

winches or cranes

�Pontoons or barges needed

COMPRESSION

OF RUBBER

GASKET

COMPLETING THE INSTALLATION

�FINISHING

� Foundation

� Backfill trench

� Protect top of tunnel

� Finish insides

LAND-SIDE INTERFACES

�Ventilation buildings

�Earthquake joints

�Cut-and-cover tunnel

�Open approaches

�Sequence IMT-C&C schedule

driven

�IMMERSED TUNNEL CHALLENGES

�Use Advanced Construction Techniques

�Use Latest Ventilation Techniques

�Select ideal Immersed Tunnel Alignments

�Determine Construction and Staging Locations

�Deal with Difficult Ground Conditions

�Dredging and Disposal

FINDINGS OF STUDY FOR OF AN IMMERSED TUNNEL IN IZMIR BAY, TURKEY

� The proposed izmir bay immersed tube tunnel (ibitt) will measure 40 m in width

and 7.6 km in length. The tunnel is characterized by a rectangular cross-section, and

will have 2x3 road traffic lanes on both sides, and a 2x1 railway tracks in the middle.

An immersed tube tunnel construction is considered along this route for the

following reasons:

�Izmir bay is relatively shallow (<25 m) so it meets the maximum depth criteria (60

m) for constructability

�Seabed soil is generally made of the non-cohesive very loose to loose silt-sand

mixtures, with a very low bearing capacity, which can be improved by suitable soil-

improvement technique

�By selection of a straight-line route between two sides of the bay, the tunnel can

be connected to the existing highway junctions and nearby railway lines

�The buried tube tunnel surrounded with a selected compacted fill in the tunnel’s

dredged ditch has a better earthquake response when compared to a much heavier

elevated bridge structure

�Substantial foundation cost savings, compared to other fixed-crossing options, will

be realized due to the fact that the immersed tube tunnel makes use of water-

buoyancy (Archimedes principle), which enables smaller load transfer to the very

loose seabed soil with very low bearing capacity.

CONSTRUCTION OF AN IMMERSED TUBE TUNNEL ACROSS THE IZMIR BAY WILL ENABLE:

� Direct link to the existing highway and railway junctions in the north and

the south districts.

� Also, traffic congestion in the centre of the city will diminish substantially.

� The tunnel will considerably shorten the commuting distance between the

Çeşme-Motorway and Izmir-Çanakkale Highway by about 40 km.

� Shorter distance & smooth drive -- Leads to considerably Lower petrol

consumption leading to considerable reduction in foreign exchange outgo

for the import of petrol -- highly beneficial to national economy.

� Quality of life and air for people living in the city will be improved, as

transport difficulties and environmental pollution will decrease.

CHINA’S PLANS LONGEST UNDERWATER TUNNEL ON THE PLANET

PLANNED SUBMERGED TUNNEL IN CHINA

�ESTIMATED LENGTH - 123KM

� LONGER THAN COMBINED LENGTH OF WORLD’S TWO

LONGEST UNDERWATER TUNNELS—JAPAN’S SEIKAN TUNNEL

AND CHANNEL TUNNEL BETWEEN THE UK AND FRANCE.

�CONNECT PORTS OF DALIAN AND YANTAI – 105 MILES APART

AS CROW FLIES

�AT PRESENT DRIVE BETWEEN PORTS TAKES – 7-8 HRS

�TUNNEL WILL SHORTEN DRIVING TIME TO ONE HOUR.

�PASSES THROUGH TWO SEISMIC FAULT ZONES –

CONSTRUCTION TO WITHSTAND EARTHQUAKE OF EIGHT

MAGNITUDE

�Development of International cities across water bodies

http://www.airpano.com/360Degree-VirtualTour.php?3D=Shanghai-China

�Development of International cities across water bodies

http://www.airpano.com/360Degree-VirtualTour.php?3D=Honkong

THANK YOU