Civil Engineering

Overseas Projects

Turkey's Long-Standing Dream" Fulfilled with Many World's First Tunneling Technologies
-Bosphorus Strait Crossing Railway Tunnel

The Bosphorus Strait Crossing Railway Crossing Tunnel is a megaproject with a total length of 13.6 km, involving the construction of an immersed tunnel of 1.4 km length crossing the Strait, and 9.5 km of twin-bored shield tunnel (2 lines, 1 in each direction), 3 underground stations, and 1 above ground station. The concept of a tunnel crossing the Strait was a long-standing dream of the Turkish people, for which outline design drawings were prepared in 1860 during the Ottoman era. The construction was carried out by Taisei in a joint venture together with 2 Turkish construction companies, in order to realize this dream project which has major significance for the world.
The part of the tunnel below the sea was constructed by the immersed tunnel method, in which concrete segments were sunk to the bottom of the sea and joined. The part of the tunnel on land used various tunnel construction methods such as shield, NATM, etc.
The immersed tunnel succeeded in connecting the tunnel segments to form the world's deepest immersed tunnel (depth from the surface 60 m). In addition, it was the first time that a seabed tunnel (immersed tunnel method) and a land tunnel (shield method) constructed by different methods were successfully directly connected under the sea.

Client : General Directorate of Railways Ports and Airports Construction (DLH), Turkish Ministry of Transport

Designer : Taisei Corporation, Gama, Nurol JV

Year completed : 2014 (Partial opening October 2013)

Location : Istanbul City, Republic of Turkey

Recipient of the "Technology Award" in 2015 from Japan Concrete Institute

Our Main Achievements (Overseas)

Singapore Downtown Line (C907)

Singapore Downtown Line (C907)

Taisei has constructed the stage 1 section 907 part of the Downtown Line, the longest MRT line in Singapore having a total length of 40 km and 33 stations. This lump-sum construction contract that included Downtown Station and the cut and cover tunnels to the west and east sides contributes to enhancing the rail network of Singapore.

Client : Singapore Land Transport Authority

Designer : AECOM Singapore Pte Ltd

Year completed : 2013

Location : Marina Bay area, Republic of Singapore

Sri Lanka Southern Expressway

Sri Lanka Southern Expressway

Taisei has constructed 32 km of Sri Lanka's first major Expressway. As a result of completion access from the suburbs of Colombo to the World Heritage City of Galle, and to beautiful tourist beaches has been improved. It is expected that local employment will improve as a result of the development of tourism.

Client : Road Development Bureau, Ministry of Transport, Government of Sri Lanka

Designer : PCI, Japan Bridge & Structure Institute, Inc.

Year completed : 2012

Location : From Colombo to Matara South, Democratic Socialist Republic of Sri Lanka

Taiwan Coal Landing Pier

Taiwan Coal Landing Pier

This project included the construction of a pier for handling coal about 2.2 km into the sea and a jetty for access from land from the Taiwan Power Company Hsing-ta Power Plant in the outskirts of Kaohsiung City. This is a large-scale structure in the open seas of Taiwan that is frequented by typhoons, and the outstanding technical capabilities of Taisei on this project were highly evaluated.

Recipient of the Chinese Institute of Engineers Award for Construction Excellence

Client : Taiwan Power Company

Design and related consultancy : UNION-TECH ENGINEERING CONSULTANTS CO.

Year completed : 2008

Location : Hsing-ta, Taiwan

Thailand Bangkok Ring Road Cable-stayed Bridge

Thailand Bangkok Ring Road Cable-stayed Bridge

This project involved the construction of double PC-steel composite cable-stayed bridges across the Chao Phraya River on the Bangkok Industrial Ring Road, connecting the center and outskirts of Bangkok. Traffic congestion has been relieved as a result of completion of the bridge, contributing to the development of the local economy.

Recipient of the Japan Prestressed Concrete Institute(JPCI) Award

Client : Ministry of Transport, Kingdom of Thailand

Designer : Epsilon, Norconsult, Mott MacDonald JV

Year completed : 2006

Location : Bangkok to Samut Prakan, Kingdom of Thailand

Domestic Projects

Constructing a Major Artery in the Tokyo Area
-Tokyo Gaikan Expressway Tajiri construction

The Tokyo Gaikan Expressway forms a ring about 15 km from the center of Tokyo. After completion, it is expected to solve the chronic traffic congestion in the Tokyo area by allowing traffic that is just passing through to bypass the city center.
We are constructing jointly with other companies the Keiyo Junction (provisional name) underground, to connect the Gaikan Expressway with the Keiyo Road in Ichikawa City, Chiba Prefecture. This is a complex and extremely difficult construction that includes a total of about 1 km of main line and 4 ramps (connecting roads) in both directions.
Of these, the cut and cover method cannot be adopted for A ramp and D ramp, so construction is being carried out by the shield tunneling method.
In particular a normal shield machine cannot be used for D ramp due to sharp curve and only 2 m of earth cover, so our proprietary harmonica method, which is patented, has been adopted to construct the tunnel with small propulsion devices with the tunnel cross-section divided into smaller cross-sections. In addition, in order to minimize settlement of the prefectural road above D ramp as much as possible, an underpinning method, which is also patented, is being used in which after completion of the top portion of the tunnel, support piles are constructed from the segment into the ground, then the bottom portion of the tunnel is excavated.

Client : East Nippon Expressway Company Limited

Designer : Taisei Corporation and others

Location : Ichikawa City, Chiba Prefecture

Scheduled completion : October 2017

Introduction of our own technology
Harmonica method+Underpinning Method (D ramp) (patented)
  • 1. Harmonica Excavation

    The top portion of the tunnel is constructed by repeatedly using small box type propulsion devices.

  • 2. Earth Retaining, Construction of Top Floor Slab, and Underpinning

    After completion of harmonica propulsion, support piles are driven from the box members of the tunnel top portion into the ground, the tunnel top slab is constructed, and supported by the piles.

  • 3. Excavation, Construct Bottom Slab and Side Walls, Backfilling, Remove Piles

    The space in the bottom portion of the tunnel is excavated, and the tunnel bottom slab and side walls are constructed to complete the tunnel.

  • Harmonica propulsion can achieve safe and efficient construction with high accuracy control of attitude.

  • View of completion of excavation. The width was about 90 m at the widest location.

Large Section Slurry Earth Pressure Shield Method (A ramp)

A ramp, which passes under the tunnel box sections of the Gaikan Main Line, is being constructed using a large cross-section shield machine. The latest large section slurry earth pressure shield method has been adopted to enable stable excavation by injecting an additive to the soil excavated at the front surface of the machine, and enhancing the fluidity of the soil and the water tightness.

A Construction Site Where Women can Work with Vitality "Team Nadeshiko Gaikan Tajiri"

Today, with so many outstanding activities of women in various fields of society, more women engineers and craftswomen are working at construction sites. On the Tajiri construction site, 10 female members of staff from the joint venture and subcontractors have formed the "Team Nadeshiko Gaikan Tajiri", putting their efforts into creating an environment where women can work with ease, by undertaking modifications to changing rooms and toilets, etc., with the aim of creating a construction site where women can work with vitality.

Our Main Achievements (Domestic)

Metropolitan Expressway Central Circular Route Shinagawa Line Tunnel

Metropolitan Expressway Central Circular Route Shinagawa Line Tunnel

The Metropolitan Expressway Central Circular Route Shinagawa Line tunnel, developed to relieve traffic congestion in the Tokyo area, has been completed using the company's most advanced shield tunneling method. As a result of opening the Shinagawa Line the Metropolitan Expressway Central Circular Route is now completely in service. Major environmental improvements are expected, such as relieving traffic congestion and reduction in the quantity of vehicle emissions.

Client : Metropolitan Expressway Company Ltd.

Designer : Oriental Consultants Co., Ltd.

Location : Shinagawa-ku to Meguro-ku, Tokyo

Year completed : 2015

Joban Expressway (Sakamoto Section)

Joban Expressway (Sakamoto Section)

The final section to open within Miyagi Prefecture (total construction length 5.4 km), which was ordered immediately after the earthquake, has been constructed. The main types of construction included cuttings, bridge substructures, and culverts. A total of about 300 km of Expressway connecting the coast of Miyagi Prefecture with the Tokyo area was completed and opened to the public in March 2015.

Client and designer : East Nippon Expressway Company Limited, Tohoku Branch

Location : Yamamoto Town, Watari District, Miyagi Prefecture

Year completed : 2014

Midosuji Utility Conduit

Midosuji Utility Conduit

This is a public utility conduit that accommodates important networks such as water supply pipes and electrical power cables, located 30 m below ground in the center of Osaka. Branch shafts at 7 locations were constructed using the upward inclined shield construction method.

Client : Ministry of Land, Infrastructure, Transport and Tourism, Kinki Regional Development Bureau

Designer : Taisei, Penta Ocean Special Construction J/V

Location : Namba Naka, Namba-ku to Sonezaki, Kita-ku, Osaka City, Osaka Prefecture

Year completed : 2014

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