Subsidence on an apartment building in Yokohama, Japan has been found to be caused by inadequate foundations and that records were falsified by the contractor.
Investigations following the subsidence show that at least 70 out of the 473 of the piles installed at the site 10 years ago did not reach the design criteria and records of the construction were altered.
Initial investigations into the work by Asahi Kasei Construction Materials has suggested the problem in Yokohama is not an isolated case.
Japan’s Ministry of Land, Infrastructure, Transport and Tourism has ordered Asahi Kasei to carry out checks on 3,040 other buildings built by the company in the last decade by 13 November.
Asahi Kasei has declined to comment on which buildings might be affected by the problem but has published data on the types of buildings that may be affected and the prefecture locations.
With regard to the problems at the apartment building in Yokohama, the company has said: “It has become clear that Asahi Kasei performed faulty installation of a portion of foundation piles, and diverted and modified data in the corresponding installation report, in work subcontracted by Sumitomo Mitsui Construction.”
Asahi Kasei has appointed an independent commission to carry out an investigation.