Ministry of Land, Infrastructure, Transport and Tourism Method for Ensuring the Implementation of Supervision NAKAE Hajime Architecture & Building Engineering Division, Government Buildings Department, MLIT

Problem caused by inconsistency of current system of supervision and/or inspection 1.Malicious modification of the structural statement by a building engineer  Concerned projects: 205 (1990~2005)  Projects modified maliciously : 99 (1997~2005) 2. Wrong execution in the construction work for a government office building  Mistake of the size of a column  Mistake of the number of main reinforcements

Column Section and Arrangement of Bar Column executed wrong in construction work Execution drawing M.R. 12-D32 Main Reinforcement M.R. 18-D32

Situation of the Construction Work

Cause of the Wrong Execution contract Supervision and/or inspection MLIT Sub- contractors General Contractor Supervising Office 1.Sub-contractor made wrong document for processing main reinforcements. 2.General contractor overlooked the mistake of document. 3. Main reinforcements were assembled wrong by sub- contractor. 4. General contractor overlooked again the wrong execution of assembling work. 5.Supervisor and inspector overlooked it, too.

Regulation in the Specification Steel Reinforcement Arrangement Inspection The reinforcing bars arrangement of the main structural portion shall be inspected by the Supervisor prior to the casting of concrete. The Common Specification for Architectural Construction Work The Supervising Method for Architectural Construction Work Steel Reinforcement Arrangement Inspection Main supervising points : Numbers, cover of concrete, intervals, positions, and so on of major arrangement of bars Supervising action : Visual inspection and /or measurement Supervising guideline : Conformity to the working drawing will be verified. Reference materials : Construction report and Photos

Problem to be solved in the Supervising Method 1.Inspection method is not clarified concretely. 2.It cannot be traced later whether all the main supervising points were inspected. 3.The extent to which each concerned body take charge of is ambiguous.  General contractor  Supervisor  Inspector

Consideration in Reviewing the Method 1.The inspection implemented by all the concerned bodies must be recorded. 2. It must be recorded to have inspected all the main supervising points. 3.All the concerned bodies and the content of the inspection must be traceable. MLIT will examine and establish a checklist and/or other materials.

Example of Checklist

Theme of Examination in the Future 1.Application to other construction work 2.Application to design

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