Development of a structural health monitoring tool for underwater concrete structures

Limited studies have gathered information on structural health monitoring (SHM) of underwater structures, and most of those studies are outdated. The existing methods evaluated structural distresses separately, without accounting for the correlation between the distresses. This study developed a SHM tool which accounts for the reciprocal relationships and priority weights of different structural distresses, and assessed underwater structures using the developed structural health monitoring tool. A new rating method was developed using fuzzy analytic hierarchy process (FAHP) which incorporates visual inspections of surface distresses, nondestructive tests (NDTs), crack details, hydraulic conditions, and casual characteristics of the underwater structures. The SHM tool was applied to 12 underwater structures, including bridges, dams, canals, water tanks and quay walls. The results of NDTs such as rebound hammer tests and ultrasonic pulse velocity tests, crack surveys, and visual observations on underwater concrete structures are employed in the SHM tool and the structures were rated using priority weights allocated to different attributes. The SHM tool developed in this study supports enhanced efficiency and effectiveness of structural health monitoring of underwater structures and proposes a numerical framework which can be employed to rate and compare the structural health of different underwater concrete structures.