Technology solutions for strategic bridge inspections in South Africa

Abstract

Principal bridge inspections for strategic bridges require an Under-bridge Inspection Unit (UBIU). Strategic bridges have restricted access due to the height and size of the structures or when the structure is located over a perennial river. The cost associated with strategic bridge inspections can be substantial depending on the size of the structure and duration of inspection. The Council for Scientific and Industrial Research (CSIR) has been investigating the application of new technologies such as Unmanned Arial Vehicles (UAVs) to capture image data and photogrammetry software to process images and creating point cloud models, to enhance the current bridge inspection methodology in accordance with Technical Methods for Highways (TMH) 19. Research to date indicates that bridge inspections can be performed off-site using only point cloud models and captured images, to identify defects and complete inspection forms as an alternative bridge inspection methodology. This paper investigates the practicality of replacing the use of an UBIU for strategic bridges and alternatively capture image data with an UAV and performing inspections using the new proposed inspection methodology. The paper also includes the comparison of the cost and time components of the new inspection methodology versus traditional TMH19 visual inspections. This study aims to reduce the cost of bridge inspections and to improve the safety of bridge inspectors.