Sewer condition assessment involves the determination of defective points and status of aged sewers by a CCTV inspection according to the standard manual. Therefore, it is important to establish a reliable and effective standard manual for identifying the sewer defect. In this study, analytic reviews of the CCTV inspection manuals of the UK, New Zealand, Canada and South Korea were performed in order to compare the defect codes and the protocols of condition assessment. Through this, we also established the standardized method for defect code and revised the calculation method of assigning the condition grade. Analyses of the types and frequencies of sewer defects that obtained by CCTV inspection of 7000 case results, showed that the joint defect and lateral defect were the most frequent defects that occurred in Korea. Some defect codes are found to be modified because those did not occur at all. This study includes a proposed new sewer defect codes based on sewer characteristics.

This study was performed to analyze the importances review on deterioration items of concrete retaining wall using statiscal analysis. As a result of study, the main deterioration items of concrete retaining wall were found out and the results can be utilized for the efficient management.

This study was performed to analyze the deterioration items of jointed rock slope using the Precision Inspection Results. As a result of study, the deterioration items of jointed rock slope was found out. The results can be utilized for the efficient management.