The land ministry is set to impose multiple penalties against Sumitomo Mitsui Construction Co. and two other contractors over a tilting condominium in Yokohama and widespread data falsification, informed sources said.
Business suspensions as well as other penalties could be handed out as early as this month following the discovery of illegal practices such as blanket subcontracting. The penalties would fall under the construction business law, the sources said.
Additional checks have been ordered for the condominium, which was found to have had defective piling work.
As of Dec. 25, data manipulation had been confirmed in piling work conducted by Asahi Kasei Construction Materials Corp., which was subcontracted to carry out the piling work, for 360 building projects, including the condominium complex in Yokohama. Eight other companies also manipulated data for 56 projects.
Falsified data included figures showing that piles had reached the bearing strata under the ground, and the amount of cement used to fix piles.
Sumitomo Mitsui Construction was the prime contractor for the Park City Lala Yokohama complex in Tsuzuki Ward, Yokohama, that included the tilting building.
The piling work was subcontracted to Hitachi Ltd. subsidiary Hitachi High-Technologies Corp., which then commissioned the work to Asahi Kasei Construction Materials Corp., an Asahi Kasei Corp. unit.
An on-site manager of Asahi Kasei Construction was found to have manipulated the piling data.
Sources say Sumitomo Mitsui Construction did not check piling data until it received reports on the work. Furthermore, the firm failed to provide appropriate direction to the primary and secondary subcontractors, even though it knew that neither had a full-time on-site manager as required under the construction business law.
Hitachi High-Technologies left most of the construction work to Asahi Kasei Construction and submitted a construction plan created by the Asahi Kasei unit without checking it.
The Asahi Kasei Construction project manager showed up at the site only on 12 days during the estimated three-month construction period, because the official was involved in two other projects.
The construction business law bans blanket subcontracting, as responsibility becomes unclear for construction projects and the possibility of slipshod work may increase.
The sources said the ministry believed that blanket subcontracting was conducted between the two subcontractors, while Sumitomo Mitsui Construction failed to correct their misconduct, the sources said.