Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Basic study on Anomaly Detection for Port Infrastructure MaintenanceShogo Miyajima
Graduate School of Management, Kyoto University
Kyoto, Japan

ABSTRACT

time of inspection and diagnosis, to analyze them across facilities, andto study the mechanism of deformation occurrences if necessary.
Results should be reflected frequently in design and construction,
which are the preliminary stages of facility development, so thatmaintenance and management can be performed more easily.
As abovementioned, most of the port and harbor structures are locatedunder the sea or ground; thus, it is difficult to inspect them with a close
visual inspection. Neither is it financially or technically feasible toconduct visual inspections of all the components and parts of thestructures. Therefore, it is essential to identify these components andparts that require inspection intensively and with priority. Whenconsidering such a strategic inspection policy, it is necessary to: 1)
evaluate components and parts that are deteriorating rapidly and may
potentially be damaged in some way; 2) identify components and parts
that are important for ensuring the functions and safety of the structures.
The purpose of this study is to develop a methodology for theevaluation of potentially damaged components and parts, based on past
inspection results from the viewpoint of number 1) above (hereinafterreferred to as the "potential evaluation" ).
Due to the difficulty of visual inspection for port and harbor structures,
it is rare to have past inspection results of the port and harbor structuresthat must be inspected. Therefore, we have no choice but to evaluate
the possibility of damage to the components and structure parts basedon past inspection results of similar port structures. To develop a
strategic inspection policy for port and harbor structures, an AI systemthat uses machine learning to support the evaluation of possible
deterioration for port and harbor structures is an effective strategy. In
this study, I propose a new method to evaluate the degradation potentialof port structures using machine learning. The purpose of this study is
to investigate the possibility of machine learning for the damage
assessment of port structures based on available past inspection results.
The basic concept of this research is explained in the next Section,
followed by anomaly detection test by machine learning andinvestigation of the possibility of understanding the spatial correlation
distribution.

To maintain proper performance of port facilities over an extended
period, maintenance management based on inspection and diagnosis isessential during the maintenance phase. There is a growing concern
about the shortage of engineers, so improving labor productivity has
become an important issue. In this study, we investigate themethodology of using machine learning to extract data that requires
detailed confirmation from the inspection and diagnosis results in themaintenance of port infrastructure. Our findings confirmed that
abnormal data can be extracted from the field data, and the possibilityof understanding the spatial distribution of abnormal data is suggested.

KEY WORDS: port facilities; maintenance; inspection and diagnosis;
machine learning; spatial interactions; asset management.

INTRODUCTIONPort and harbor facilities are subjected to severe natural environments
so their performance often deteriorates, even during their service period(Kobayashi and Ueda, 2003). With the amendment of the Port andHarbor Act of 2013, inspections for port and harbor facilities became
mandatory, and inspections and diagnoses based on maintenance plans
were conducted (PHB-MLIT, 2019). In the maintenance phase of port
infrastructure, the degree of facility deterioration is determined basedon the results of inspection and diagnosis, and decisions are made on
the necessity and priority of countermeasures, based on the calculated
life cycle cost (LCC).
The inspection and diagnosis of port and harbor facilities presents avaluable opportunity to obtain important information on theirdeformation. It is necessary to utilize the information obtained from theinspection and diagnosis as effectively as possible. In particular, sincemost of the port facility structures are fixed under the sea or in the soil,and restrictions occur while the facilities are in service, there are limits
as to what can be done during the maintenance phase. Therefore, it isdesirable to determine those deformations that require attention at the2805