Lessons Learnt from Bridge Reconstructions Post Successive Disaster Events in the Eurobodalla LGA

Sale, Maggie (2022) Lessons Learnt from Bridge Reconstructions Post Successive Disaster Events in the Eurobodalla LGA. [USQ Project]

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The 2019-20 Australian bushfire season burnt over 17 million hectares overall including over 5.3 million hectares (6.7%) of NSW and over 80% of the Eurobodalla LGA, the worst impacted LGA. The lengthy droughts and extreme heat in 2019 contributed the making this the worst bushfire on record. One that warranted a large-scale response with interstate and international personnel deployed, had a large negative impact on flora and fauna, and damaged or destroyed 18 timber bridges in the Eurobodalla LGA. Post fires in 2020 the weather was warm but very wet which triggered multiple floods events within the Eurobodalla LGA causing another non-fire damaged timber bridge to fail which brought the total of disaster damaged bridges to 19. These impacts were further amplified due slope instability, landslides and the COVID-19 pandemic.

This paper documents the research completed on timber bridges in NSW, bushfire damaged timber bridges, and project management practices, the recovery process of ESC’s disaster damaged bridges, the assessment of each project based on scope, schedule, cost, quality, and stakeholders, and notes the lessons learnt from the bridge reconstructions. The bridges in the analysis include a timber bridge repair, footbridge replacement, construction of five replacement culverts, 11 modular bridges, and one steel bridge. The 19 structures were completed within 2.5 years with 18 rebuilt as resilient.

The analysis delivered results for each of the criteria assessed. The primary reason for scope variations was increased scour protection to reduce the effects of flooding however a couple were design changes. Nearly all the bridge projects deviated from the original schedule with the variations in commencement dates and variations in duration primarily due to the frequency of rain, flood events, and landslides, site access issues and resource availability although a few are due to scope variations. The most frequent reason depicted for cost variation was the increased cost of transporting components, underestimation of number of inspections required, escort cost for concrete trucks due to remote location of bridges, the need for increased scour protection, and the rises in industry prices, particularly steel. All the projects were compliant to all relevant standards and technical specifications however there were a number of projects that didn’t complete and/or document the QA process. The majority was notifications were complete, the exception being the projects completed very early on in the reconstruction process. Improvements could be made on communicating with residents however the relationship with TfNSW through the process was good.

The outcome of this report was the successful identification of areas for improvement and the creation of a list and flowchart demonstrating the best process for rebuilding destroyed bridges. These practices will assist in improving the process for any further similar situations through the implementation of more effective and efficient methods, increasing the number of resilient structures, and reducing the impact of disasters to the community.

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Item Type: USQ Project
Item Status: Live Archive
Faculty/School / Institute/Centre: Current – Faculty of Health, Engineering and Sciences - School of Engineering (1 Jan 2022 -)
Supervisors: Thorpe, David
Qualification: Bachelor of Engineering (Honours) (Civil)
Date Deposited: 20 Jun 2023 01:28
Last Modified: 20 Jun 2023 01:28
Uncontrolled Keywords: disaster event; bushfire season; bridge reconstruction
URI: https://sear.unisq.edu.au/id/eprint/51892

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