Investigating the maintenance costs and condition states of deteriorated small road structures

Hadonou, Patient (2018) Investigating the maintenance costs and condition states of deteriorated small road structures. [USQ Project]


Over the past decade, various regions of Queensland have been impacted by two extreme flood events in 2011 and 2013. One such region was the Lockyer Valley Region (LVR). As a result, a community study by a team of researchers in partnership with the Natural Hazard CRC demonstrated that although small, road structures such as floodways and culverts are very important toward maintaining the resilience of rural.

Prior to the floods, the maintenance of smaller road structure had been neglected. Services to culverts and floodways were provided on a need-basis. This led to two prominent issues. Firstly, inspectors took longer to identify the causes of failure due to the lack of reports regarding condition states prior to failure. This delayed repairs. Secondly, a reactive approach can often mean that needs might not be recognised until a major failure has occurred and it is too late. Hence the importance of an inspection framework. A fully functional inspection framework allows the inspectors to gather the condition states of structures which can then be used to predict future conditions. This study uses the Stochastic Markov Chain approach in order to develop deterioration models for various Lockyer Valley Floodways and Culverts. The models were calibrated using the non-linear optimisation method, validated using Pearson’s Chi-squared method and then used to predict how those small road structures over time. Finally, a simple cost estimation was undertaken considering the effects of replacing individual structures as a form of maintenance. The research paper found that although generally accurate, the Markov Chain method is more reliable using condition state data based on constant monitoring rather than snapshot data. Snapshot data makes it almost impossible to discern between structures that naturally deteriorated and those that were constantly maintained. It is then difficult to filter out maintained structures from the model. In most cases however, the Markov Chain Approach was more reliable than deterministic methods as it takes into account the stochastic nature of deteriorating civil structures. The cost estimation process itself was limited due to the unavailability of accurate cost data. Moreover, it was possible to deduct based on a replacement scenario that although some structures could be cheaper to replace, the frequency of the replacement was a crucial factor.

Overall, this research project provides a simplistic and reliable method to predict deterioration states of deteriorated road structures. Through future studies and more detailed inspection data, it will be possible to calibrate deterioration models by filtering out outliers. The current inspection data in particular only provides the condition states of the overall structures. By implementing an inspection framework that gathers condition states for each element within a structure, a more in-depth analysis can be carried out comparing the deterioration of structural elements.

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Item Type: USQ Project
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Civil Engineering and Surveying (1 Jul 2013 - 31 Dec 2021)
Supervisors: Lokuge, Weena; Karunasena, Karu
Qualification: Bachelor of Engineering (Honours) (Civil)
Date Deposited: 05 Sep 2022 04:33
Last Modified: 29 Jun 2023 01:38
Uncontrolled Keywords: road structures; floodways; culverts; maintenance costs

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