Seismic reinforcement (retrofitting)

Kobe Former Foreign Settlement Building No. 15 in Chuo Ward, City of Kobe is a two-story wood-frame brick building in the colonial style built in 1881.

The building collapsed following the Great Hanshin-Awaji Earthquake, but 70% of the original building materials had to be reused for it to remain a cultural property. This was the first important cultural property to be retrofitted with seismic isolation.

The Taisei Yugawara Training Club, completed in 1964, is a large building complex built on a sloping site that consists of 3 main buildings (2 stories, 7 stories, and 16 stories), and a 7-story building to the east. Seismic isolation between floors has been provided by cutting columns on the 8th floor of one of the main buildings in half and installing seismic isolators. As a result, the response acceleration and shear force above the seismically isolated floor have been reduced to approximately 1/5 to 1/10 of their initial values, eliminating the need for reinforcement of the structure above. The load on the substructure has also been greatly reduced. The east wing has a seismically isolated foundation, eliminating the need for reinforcement of the superstructure.

Built in 1929, the main hall of the Honganji Obihiro Betsuin temple has a large roof with wooden trusses supported by RC columns and walls. To preserve the 69-year-old (as of 1995) main hall for many years to come, seismic isolators were installed in the building foundation to reduce seismic input and improve seismic resistance. The work began with the construction of a temporary foundation to support the superstructure, followed by the installation of new RC grade beams on both sides of the existing grade beams and the removal of the existing foundation in places where the seismic isolators were to be installed. A new pile foundation was installed where the seismic isolators were located, and the existing foundation was completely removed after installation.