Abstract
M.Phil. (Engineering Management)
Railways are important in the transportation of bulk commodities and in the economic integration of Africa, however; only 79% of the African railways are operational. Railway transportation fares better than road transportation on aspects such as energy use, freight costs and air pollution. The management of railways encompasses extensive information, which can be managed better with the use of technology. The research project studies a literature on the maintenance management and state of bridges and tunnels globally and applies the literature information in a case study. Bridges, which form part of transport infrastructure, are inspected at optimum intervals. Visual Inspections (VI) are conducted, however, VI have limitations that compel the asset owners to explore alternative methods. The alternative methods and systems of inspections include robots, sensors, Unmanned Aerial Vehicles, convolutional neural networks, echo state networks, Infrared Thermography and ultrasonic waves. Bridges are ageing and are being overloaded, which makes it important that real time monitoring, or Structural Health Monitoring (SHM) is implemented. SHM can assist in the optimum management of bridges with respect to bridge use, maintenance and replacement. A Bridge Management System, which is a computer-aided system, which prioritizes bridge maintenance by considering all relevant aspects, such as structural integrity, deterioration progression, economics and environmental factors. Railway bridges specifically also experience high dynamic loading influences and must be analysed for fatigue. Tunnels are difficult to inspect visually, so noncontact acoustic inspections are conducted. The prediction of the remaining life of tunnels also provides an alternative to visual inspections. Maintenance management and the state of bridges and tunnels is studied using the South African Railway Company (SARC) as a case study. The concepts that are studied at the SARC are bridge inspection types and frequencies, Structural Health Monitoring (SHM), overloading and bridge ageing. The concepts studied are chosen because of challenges at the SARC. A stratified sample with a size of 85 bridges is selected from a total of 2 287 railway bridges to study the selected concepts using quantitative primary data. The study finds that the SARC has two bridge inspection frequencies, the more frequent inspections are conducted in two-year intervals and the less frequent inspections are conducted in eight-year intervals. SHM is implemented on one percent of the SARC bridges whilst 11% of the bridges are overloaded. SHM is conducted on 11% of the overloaded bridges. The SARC bridges are younger than the presumed 100-year bridge design life. Compared to other bridge owners/jurisdictions, the SARC inspection frequencies compare well. The SARC bridges are generally younger comparisons of the comparing bridge owners/jurisdictions.