Overview of the Large-Scale Repair Work on the Arakawa Bay Bridge Since fiscal year 2014, the Metropolitan Expressway Authority has been carrying out large-scale renewal and repair work at various locations along 63.7 km of its 327.2 km total route as part of the “Metropolitan Expressway Renewal Project.” This magazine has also reported on large-scale renewal project sites such as the “Kousoku Daishi Bridge” and the “Higashi-Shinagawa Pier and Samezu Reclamation Area.” In the case of the Arakawa Bay Bridge, detailed inspections utilizing new technologies revealed approximately 4,500 instances of damage, 53% of which were attributed to corrosion and coating degradation; as a result, large-scale repair work was added to the project in 2024. Along with the “Haneda Tunnel” on Expressway No. 1, the renewal section is expected to span 21.6 km, with a projected project cost of 305.6 billion yen. Overview of the Arakawa Bay Bridge Opening Date: January 20, 1978
Length: Approximately 840 meters
Number of lanes: 8 lanes in both directions (6 lanes in both directions at the time of construction)
Structural Type: Truss bridge (central span is a steel-deck box-girder bridge)
Structural Overview: 4 fixed spans, 3 suspension spans; steel deck box girder in the central section. Functional enhancement and seismic retrofitting of the Arakawa Bay Bridge. 1987–1988: Repainting work
1995–1999: Widening project to expand the road to four lanes (Shin-Kiba to Kasai)
1995–1999: Seismic retrofitting of RC bridge piers
2001–2004: Installation of bridge collapse prevention systems
2008–2009: Seismic retrofitting of steel bridge piers
2008–2013: Seismic retrofitting of the superstructure; repainting of the truss floor system (damage occurred during construction due to the Great East Japan Earthquake)
2011–2012: Emergency Restoration Work Following the Great East Japan Earthquake The scope of this project covers a 460-meter section on the Koto Ward side, where work will include repainting the bridge, repairing various types of damage, and installing inspection walkways and permanent scaffolding. Although the main truss of the Arakawa Bay Bridge had been repainted once and the deck girders twice in the past, those projects involved “Type 3 surface preparation,” which removed only the degraded paint film, resulting in a thick coating. Since there is a risk that the coating could peel off if left as is, this time we will perform “Type 1 surface preparation”—which completely removes not only rust but also the old chlorinated rubber-based coating via metal blasting to expose the steel surface—and apply a fluorocarbon coating for a highly durable finish. In addition to the existing inspection walkways, two new walkways will be installed on the upper side of the truss section beneath the deck, and one on the lower side. Furthermore, permanent scaffolding will be installed in the central span. Other work includes replacing damaged drainage pipes, bolts, and gusset plates, as well as repairing areas of delamination on the reinforced concrete piers. Work will proceed from the Koto Ward side, with “temporary scaffolding erection,” “repair and reinforcement,” and “repainting” carried out one span at a time, gradually moving toward the Edogawa Ward side. The construction period is estimated to be approximately 8 months for scaffolding erection and related work, and another approximately 8 months for painting and inspection, for a total of about 7.5 years from March 29, 2025, to December 26, 2032. The Edogawa Ward side is scheduled to issue a contract in the future.
I visited the construction site where scaffolding has been set up and repair and painting work is about to begin. The area shown here is “Work Zone A,” located closest to Koto Ward, with scaffolding already in place. Repair and painting work will be carried out next. The steel structures to be painted and repaired number approximately 1,700 along the entire section (about 840 meters). The finished color will be a shade of blue named “Waterside Blue.”
© Source travel watch