To counter large-scale disasters including Nankai megathrust earthquakes and earthquakes in the greater Tokyo area, the following countermeasures are required: securing necessary trunk line cargo transportation soon after an earthquake and quickly securing the requisite minimum transportation of key emergency supplies for recovery and reconstruction hubs. In addition, the interaction of earthquakes, tsunamis, and high waves with the ground might cause coastal disasters, so it is necessary to reduce such risks.

Therefore, the themes of this research cover research and development which simultaneously achieves the two goals of improving earthquake resistance and reducing construction costs. These two goals can be achieved through diagnosis and performance verification of earthquake-resistance of facilities which address the properties of long-period and long-duration earthquake ground motion, which is expected to occur during a subduction-zone megathrust earthquake, as well as the properties of earthquake ground motion caused by local ground characteristics. Research and development are being conducted mainly on methods for investigating and diagnosing earthquake resistance as well as construction methods that improve the resistance, while using existing facilities with limited design life that were erected during the era of rapid economic growth.

We obtained 2864 strong motion earthquake records during the period between January to December 2015. We will organize and analyze these records and will then publish the data as a Technical Note of the Port and Airport Research Institute.

In collaboration with related organizations including the Ports and Harbours Bureau of the Ministry of Land, Infrastructure, Transport and Tourism, we investigated the on-site introduction of a quaywall deformation measurement tool utilizing RTK-GNSS, which is a technique to assess the post-earthquake damage conditions of port facilities and to determine whether such facilities can be used.

To develop a technique to estimate strong ground motions to prepare against large-scale earthquakes occurring directly beneath metropolitan areas, we analyzed data from several intraslab earthquakes with different characteristics and then developed and verified source models to explain those ground motions.

We conducted a study on the evaluation and analysis of liquefied ground behaviour targeting the sequenced earthquake motions and grounds involving fine contents, and elucidated the mechanism of the internal flow characteristics in association with the progress and propagation of liquefied zones.

To develop diagnostic and countermeasure techniques to improve the disaster-prevention characteristics of industrial complexes, we focused on actual coastal industrial complex facilities and confirmed the earthquake-resistance effects of the countermeasure by the model experiment using the National Research Institute for Earth Science and Disaster Resilience's large shake table (E-Defense) and conducted numerical analyses to re-create the behavior of these facilities.

We developed a numerical model for steel-pipe members to adequately represent their seismic performance and then proposed a new earthquake-resistant design method, with modified performance specifications applicable for piled piers, steel pipe sheet pile quay walls, and anchorages of sheet pile quay walls.

We took both breakwater mound/ground dynamics against tsunamis and countermeasure construction against them (reinforcing embankment) into account, and then proposed the method evaluating the stability of breakwaters.

We conducted centrifugal model experiments to study the ground stability against waves and found that inter-ground stress and water pressure affect ground stability. Also, we investigated how to reproduce wave breaking in narrow vessels, in which there is not enough distance to achieve wave shoaling, and compared the results of centrifugal model experiments with fluid numerical analyses.