Tohoku, Japan, Earthquake and Tsunami of 2011: Survey of Port and Harbor Facilities, Northern Region

This introduction provides an overview of the report of a reconnaissance trip sponsored by ASCE's Coasts, Oceans, Ports, and Rivers Institute to survey damage to port and harbor structures caused by the March 11, 2011, Japan earthquake and resulting tsunami. Background on the team members and area surveyed; Japanese port designations and seismic design criteria; and event seismology, shaking, and tsunami are included in this chapter.

During the onsite investigation conducted in Soma, the team visited two facilities. The main port consisted of a total of five planned wharfs; three were already constructed, one was under construction, and one was in planning. The fishery port consists of the main concrete frame fisheries structure located on a mole structure with an adjacent pier wrapped around the harbor. Detailed descriptions and extensive photographs of the team's findings, which focused on the design and construction of these structures, are provided.

The port of Sendai is one of the largest port facilities in northeastern Japan. The onsite investigation consisted of the container terminal at Takasago wharf, the Chuo-Kouen public park, the cargo docks at Raijin wharf, and the Takamatsu wharf. Detailed descriptions and extensive photographs of the team's findings, which focused on the design and construction of these structures, are provided.

Located within the Port of Sendai, the JX Nippon oil refinery consists of numerous process units, several tank farms, a liquefied petroleum gas terminal, truck and rail loading racks, and five marine terminals. In general, the refinery complex performed very well during the earthquake; however, the inundation by the tsunami caused widespread damage, including initiating an uncontrollable fire in the loading racks that resulted in a long term shutdown.

Matsushima is a small fishing and tourist community deep within the Sendai Bay and is well protected by barrier islands. During the investigation the team visited two small fishing and ferry terminals and a floating dock. Little damage was noted, and in comparing the damage levels on the exterior and interior towns of the bay, it was clear that the barrier islands significantly reduced tsunami damage.

The Ishinomaki port is an industrial port near the estuary of the Kitakami River. The survey team investigated six facilities, four within the main port and a tank farm and a marine oil terminal outside the port. Detailed descriptions and extensive photographs of the team's findings, which focused on the design and construction of these waterfront structures, are provided.

Onagawa is a small fishing port east of Sendai that suffered some of the most massive tsunami damage during the Tohoku, Japan earthquake and tsunami of 2011. The team visited the Onagawa Hospital and the waterfront areas extending from the northeastern portion of the Onagawa fishery port to the marina at Konori. Building structures sustained significant damage due to the combined forces of direct tsunami impact, hydrodynamic drag, and buoyancy forces while submerged. Detailed descriptions and extensive photographs of the team's findings, which focused on the design and construction of these structures, are provided.

Kesennuma is a major port for Japan's fishing industry that sustained heavy damage during the tsunami. Eight locations with the city, including a tsunami evacuation structure, a marine oil terminal, a shipyard, a floating dock, and several commercial wharfs, were investigated by the team. Detailed descriptions and extensive photographs of the team's findings are provided.

The team visited more than eight port sites from the moderately-sized port of Ofunato north to Kamaishi, including the small fishing villages of Sanriku, Sakihama, Ogihora, and Toni. The primary sites investigated in the Ofunato port area consisted of the main municipal wharf and a marine oil terminal, while in the villages the sites visited were fishing wharves. Detailed descriptions and extensive photographs of the team's findings are provided.

A number of sites in the Kamaishi, Otsuchi, and Yamada region, which are located approximately 50 km from the rupture zone, were visited by the team. The world's deepest breakwater, reaching a depth of 63 m, was completed in 2008 and is located in the mouth of Kamaishi Bay. The breakwater maintained stability during peak waves, but ultimately failed due to scour and variable hydrodynamic loads. Port facilities inspected in this area included a number of wharves and the Iwate Prefecture Oil Terminal in the Kamaishi area and several wharves and piers in Otsuchi and Yamada. Detailed descriptions and extensive photographs of the team's findings are provided.

The team visited the Miyako port area and the small fishing villages of Taro, Omoto, and Shimanokoshi along the Tohoku coast. The Miyako port consists of several gravity and steel sheet pile bulkhead structures protected by a concrete breakwater, while the fishing wharves at Taro, Omoto, and Shimanokoshi consist of gravity wall and caisson structures. Detailed descriptions and extensive photographs of the team's findings are provided.

The Kuji port area and several small fishing villages further north to Hachinohe were inspected by the team. Kuji is a moderately-sized port with concrete gravity seawalls and pile supported wharves protected by several breakwater structures. Detailed descriptions and extensive photographs of the team's findings are provided.

Hachinohe Port, located in Aomori prefecture more than 100km from the rupture zone, was the northernmost port area that the team visited. Four locations, including sheetpile wharves, container wharves, and a marine oil terminal, were inspected. Detailed descriptions and extensive photographs of the team's findings are provided.

This chapter summarizes the team's findings from all sites visited and draws general conclusions from these investigations. Topics include: earthquake and tsunami design codes; early warning systems; general construction and materials quality; sensing instrumentation; gravity, sheetpile, and pile supported structures; tanks, spheres, and vessels; anchored and unanchored equipment; piping and cranes; and tectonic plate movement and sea level rise. Also presented are the general recommendations prepared by the team for seismic and tsunami planning, analysis, and design and implementation of risk reduction measures at ports.

The shaking data provided in the appendix are intended to supplement that in the report and serve as background information to allow for more detailed analysis. All data are from stations discussed in this report.