Within the framework of the “Seismic Reinforcement Project for Large Scale Bridges in Istanbul” currently undertaken and executed by IHI, a work was newly awarded as a variation order by KGM (General Directorate of Highways, Republic of Turkey), on the seismic reinforcement work of Mecidiyekoy Viaduct, which is located in the heart of the city.

The Mecidiyekoy Viaduct is located on the Circular Road (Cevreyolu / E-5), together with other target viaducts for this existing seismic reinforcement projects undertaken by IHI, namely Bosphorus Bridge, Golden Horn Bridge and Ortakoy Viaducts. The E-5 Circular Road consists the most important trunk of traffic flow, both for Istanbul City and the nation. The road becomes of a vital demand in case of tragic earthquake, to let emergency vehicles and relief team to flow. In order to protect the E-5 Circular Road as a system and to achieve the target of this “Seismic Reinforcement for Large Scale Bridges in Istanbul”, KGM decided to incorporate Mecidiyekoy Viaduct into the scope of the existing project, undergoing under scheme of Japanese government’s official overseas assistance.

Location of the viaduct is in the very heart of the city’s crowded area, and heavy traffic is observed both over- and under the viaduct. IHI will strive to complete this reinforcement as earlier as possible, with minimum traffic disruption, in order to protect civil life from possible big disaster.

Replacement of Hanger Plates of the Bosphorus Bridge completed successfully (1st March 2008)

IHI has been awarded in bridge widening contract by the Louisiana Department of Transportation and Development in the USA.

This challenging job involves widening superstructure of the existing cantilevered truss bridge adding　travel lane and inside and outside shoulders to each direction along with two existing travel lanes and a railway without complete closure of the traffic.

The bridge was built in 1935, is located in the Greater New Orleans area. The job scope includes measurement and monitoring of the existing bridge to make sure the connection and designed load transfer with new structures.

IHI is a member of a contingent joint venture with Massman Construction and Traylor Bros. IHI takes role of the erection and fabrication engineering in the JV.

The construction has commenced in March 2008 and be completed in the spring of 2012.　

This would be the 24th bridge project for IHI in the USA. IHI is the first Japanese steel bridge builder who participate as a contractor in the US.

Bridge Type
3 continuous and 1 single span 4 main truss bridge.
<Span>: 161m+241m+162m : + 162m
<Steel to add>: approx.13,000MT.

Nishi-Shinjuku junction which is an elevated bridge located over National Route 20 (Koushu Kaido) in Shinjuku area is completed successfully. The junction is planned to serve as a connection between the existing Metropolitan Expressway No.4 Shinjuku Route and the newly built Yamate tunnel of Circular No.6 Route.
The portion undertaken by IHI (SJ32 Portion) is a double leveled overhead crossing constituting the highest part of the junction passing over the Shinjuku route. This portion is in the form of a rigid framed structure with steel piers and stiffened steel box girders at all spans.
The bridge has a very complex geometrical form involving a superstructure diverge horizontally at an angle of 90 degrees and the piers with multiple bend points designed in order to avoid the interference with the Shinjuku Route and the underground utility lines.
The erection works had to be carried out in area which is one of the most famous traffic congestion sites of Tokyo where Circular No. 6 Route intersects with the National Route 20. Furthermore the works was limited to a very narrow field due to the severe constraints caused by the existing under passing roads and the subway line as well as the surrounding buildings.
Because of the unfavorable conditions for the erections works, sophisticated techniques are employed through the combination of multiple methods such as cantilever and large block erection. Furthermore precision control of the design and the erection phase was conducted by examining the sectional forces and deformation amounts occurred at all stages of the complex erection procedure by carrying out analytical modeling.