Awarded Contract for Seismic Retrofitting of Kurushima Kaikyo Bridge and Other Construction

July 7, 2026

JFE Engineering Corporation

JFE Engineering Corporation (President and CEO: Kazumi Fukuda, Headquarters: Chiyoda-ku, Tokyo) has been awarded the contract for the "Kurushima Kaikyo Bridge Seismic Retrofitting and Other Construction" (hereinafter referred to as "the Project") by Honshu-Shikoku Bridge Expressway Company Limited (hereinafter referred to as "HSBE")

The Project involves seismic retrofitting work in preparation for major earthquakes on the Kurushima Kaikyo First, Second, and Third Bridges (total length approximately 4 km), located on the Ehime Prefecture side of the E76 Nishiseto Expressway (Shimanami Kaido).

The Kurushima Kaikyo Bridge is the world's first three-span suspension bridge, spanning approximately 4 km across the Kurushima Strait between Oshima Island and Imabari City in Ehime Prefecture. It also features a road for motorized bicycles and pedestrians. Since its opening in 1999, it has served not only as a vital transportation link between Honshu and Shikoku but also as infrastructure for tourism, including cycling, and for the daily lives of residents on the islands, being used by many vehicles, pedestrians, and cyclists. Our company was responsible for the construction of the Kurushima Kaikyo Third Bridge (total length 1,570m) as part of a joint venture, and we will apply the technology and expertise we have cultivated in long-span bridges to this Project.

The main construction details of the Project are as follows:

Replacement of existing center stays [Note 1] and side stays [Note 2] with friction dampers [Note 3] with high damping performance, which will significantly improve the safety of the bridge by absorbing and dissipating energy during earthquakes through friction.

New installation of vibration control dampers [Note 4] to control vibrations during earthquakes, effectively suppressing the risk of damage to piers and bridge collapse.

Installation of reinforcing structures, etc., at the bearing parts [Note 5] to prevent girder drop during earthquakes and to fix the bridge in the longitudinal direction, while also mitigating the impact of girder collisions during seismic events.

The objective of this Project is to enhance the seismic performance of the Kurushima Kaikyo Bridge, aiming to achieve rapid resumption of service even in the event of a major earthquake exceeding assumptions, such as a Nankai Trough earthquake, and to realize the development of resilient road infrastructure that ensures its function as an emergency transport route.

Our company has been involved in the construction and maintenance of bridges managed by HSBE for many years. For this seismic retrofitting work, we will bring together our comprehensive technological capabilities in steel bridge design, manufacturing, and erection, and reliably complete the work to ensure the safety and security of the Shimanami Kaido.

[Note 1] A device that connects the main cable and the bridge girder (stiffening girder) in the central part of the bridge. [Note 2] A component installed at the ends of the bridge (girder ends) to reduce the effects of temperature changes, earthquakes, and wind. [Note 3] A seismic isolation and damping device that efficiently absorbs bridge sway by converting vibration energy during earthquakes and strong winds into heat energy through friction. [Note 4] A device for absorbing (damping) vibration energy caused by earthquakes and wind, preventing damage to bridge girders and piers. [Note 5] The part installed between the superstructure (bridge girder) and the substructure (pier or abutment) that absorbs expansion and contraction due to temperature changes and load.

Project Overview

Project Name

Kurushima Kaikyo Bridge Seismic Retrofitting and Other Construction

Client

Honshu-Shikoku Bridge Expressway Company Limited

Project Location

Kamiura-cho, Imabari City, Ehime Prefecture (KP29.605) to Sunaba-cho, Imabari City, Ehime Prefecture (KP54.140)

Contract Amount

4,356,000 thousand yen (tax included)

Construction Period

August 1, 2026 - October 13, 2029 (1,170 days)

About Kurushima Kaikyo Bridge

The Kurushima Kaikyo Bridge is one of the bridge groups that make up the Nishiseto Expressway (Shimanami Kaido), which opened in 1999. Located in Imabari City, Ehime Prefecture, it is the world's first three-span suspension bridge spanning approximately 4 km across the Kurushima Strait between Oshima Island and Imabari. It consists of three bridges: the First Bridge (960m), the Second Bridge (1,515m), and the Third Bridge (1,570m). In addition to the expressway for automobiles, it also has a road for motorized bicycles and pedestrians, and boasts high popularity both domestically and internationally as a sacred place for cyclists.

Photo: Provided by Honshu-Shikoku Bridge Expressway Co., Ltd.

Source: "Kurushima Kaikyo Bridge | Shimanami Kaido"

https://www.jb-honshi.co.jp/shimanami/about/shimanami/p07.html

For inquiries regarding this matter, please contact:

JFE Engineering Corporation, Public Relations Office, General Affairs Department