| In the 2024 Noto Peninsula earthquake (M7.6), many road bridges were damaged due to strong motion and ground deformation. The Public Works Research Institute (PWRI) and the National Institute for Land and Infrastructure Management (NILIM) jointly investigated the damage to road structures, including 135 road bridges, as of March 2024. No major structural damage was found on 45 bridges that were designed according to design standards after the 1995 Kobe earthquake, which require bridges to withstand an M7 shallow earthquake directly below them, while 6 bridges suffered major structural damage on 91 bridges that were designed under the pre-1995 design standards.
Since no findings have been confirmed that would invalidate the current technical standards, the Road Bureau of the Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has proposed the following directions to improve of the technical standards from the viewpoint of speedy reconstruction.
- Improve the design items and contents in order to realize a damage pattern that enables rapid emergency restoration even in cases where no specific external force can be assumed.
- Ensure a structure that is easy to inspect, diagnose, and rehabilitate after an earthquake, and ensure access to the bridge.
- Consider the development of technical standards for repair, including the establishment of performance requirements and the introduction of the concept of damage control, so as to allow for flexible and appropriate measures.
We present details of the field investigation results and introduce the related research projects underway at our institute, which would contribute to the improvement of technical standards following the directions shown by the Road Bureau. |
