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Bridge Maintenance and Earthquake Protection

Many of the large bridges constructed during the heyday of rapid economic growth in Japan are now starting to age, making infrastructure maintenance an issue of increasing concern.
The Hitachi Zosen group boasts 130 years of accumulated expertise in inspection, diagnosis and evaluation of bridges as well as repair, reinforcement and renovation techniques that extend the usable life of bridges. By bringing together skills and techniques from these areas, Hitachi Zosen is able to devise comprehensive problem-solving solutions for bridge maintenance that enable bridges and in this way make an important contribution to society.

Minato Bridge

Major technologies

Preventative maintenance

At a time when much infrastructure is aging, it is increasingly important to develop preventative maintenance regimes involving early detection and repair of faults and damage in order to minimize overall life cycle costs and extend the usable life of bridges. Preventative maintenance is based on the concept of asset management predicated on efficient and effective maintenance programs.
The Hitachi Zosen Bridge Management System brings together the combined expertise of the entire Hitachi Zosen group in a wide range of fields under a systematic framework encompassing inspection, evaluation and damage forecasting systems, repair and reinforcement techniques, renovation and upgrading solutions, and total bridge replacement.

Hitachi Zosen Bridge Management System


Inspection, monitoring and emergency systems

Hitachi Zosen is developing a bridge maintenance database based on the three-dimensional product models currently used at the factory fabrication stage. Under this approach, laser scanners or equivalent are used to generate 3-D measurement data that is combined with product models to generate a comprehensive database to assist in the development of bridge maintenance solutions.
Hitachi Zosen is also working on disaster prevention and emergency systems that combine GPS technology (which played a vital role in providing measurements of tsunamis during the Great East Japan Earthquake) with the Geographic Information System (GIS) and can be used to generate comprehensive route information, monitor the structural integrity of bridges, and provide communication services at times of emergency.

the three-dimensional models using laser scanners

Seismic analysis

Seismic reinforcement of very large bridges is shifting towards damage control designs using devices that are designed to reduce seismic forces more efficiently by absorbing earthquake energy. This approach necessitates highly advanced dynamic analysis techniques.
The Hitachi Zosen group boasts extensive experience and expertise in dynamic response analysis and FEM analysis under special conditions on a wide range of different bridge types, from very large bridges to ordinary bridges. We have applied our knowledge to major reinforcement works on very large bridges such as the Minato and Tempozan Bridges in Osaka.

dynamic response analysis of the Tempozan Bridges

Renovation and upgrading

Many aging bridges suffer not only from deterioration and damage over time but also from higher traffic levels, heavier truck loads, environmental impacts such as ground subsidence and the need for improved seismic reinforcement. The Hitachi Zosen group refurbishes aging bridges using a range of techniques such as seismic reinforcement and replacement of floor systems that can extend the usable life of bridges and allow them to serve as important public assets for many more years and carry on into the next generation.
Hitachi Zosen was the first in Japan to apply the cable tension readjustment technique (on the Kamome Bridge) and has upgraded many bridges by replacing the floor system.

Kamome Bridge
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