Enhancing resilience of critical road infrastructure: bridges, culverts and floodways
Article Type: News From: International Journal of Disaster Resilience in the Built Environment, Volume 5, Issue 3
A recent research project funded by the Bushfire and Natural Hazards Cooperative Research Centre (CRC) in Australia focuses on enhancing resilience of critical road infrastructure: bridges, culverts and floodways under natural hazards. The seven-year project aims to quantify the impact of failure of road structures on the resilience of the local community, road authorities and the wider stakeholders. A conceptual framework has been developed and the implementation has commenced in October 2013.
This project will develop innovative tools and techniques for implementing strategies to enhance resilience of road infrastructure to multi-hazards of floods, fire and climate change and earthquakes. The research will commence with close assessment of two case study regions: one in Victoria and one in Queensland. It will then be expanded and validated.
Road networks and critical road structures such as bridges, culverts and flood ways have a vital role before, during and after extreme events to reduce the vulnerability of the community being served. A major gap in the current research is the lack of assessment techniques and tools to reduce the vulnerability of road structures to enhance both community and structural resilience.
The outcomes of this project will include:
Quantitative evaluation of vulnerability of road structures under multi-hazards of fire, flood, earthquake and climate change: a web based tool for design and maintenance optimisation of bridges, culverts, floodways to flood, bushfire, climate change and earthquake.
Quantifying social, environmental and economic consequences of failure: community, emergency services staff and road/local government authorities: community adaptation options to enhance resilience as an alternative to hardening of structures when critical road structures are damaged.
Input for decision support at local government and state road authorities: a new design guide for floodways, plus recommended changes to other standards.
A generic research methodology that can be applied to other infrastructure, such as transmission towers, and water infrastructure.
Prof Sujeeva Setunge (RMIT University, Australia) is leading this project and the rest of the team include:
Prof Chun-Qing Li (RMIT University, Australia).
Prof Darryn McEvoy (RMIT University, Australia).
Assistant Prof Kevin Zhang (RMIT University, Australia).
Prof Priyan Mendis (Melbourne University, Australia).
Dr Tuan Ngo (Melbourne University, Australia).
Assistant Prof Karu Karunasena (University of Southern Queensland, Australia).
Dr Weena Lokuge (University of Southern Queensland, Australia).
Prof Dilanthi Amaratunga (University of Salford, UK)
As a first stage of implementation, the research group has assessed the effect of recent flood events in Queensland, Australia, which had an adverse effect on the country’s social and economic growth. It is noted that due to climate change, frequency and intensity of recent flood events have increased. Bridges affected by 2013 flood in Lockyer Valley region in western Queensland were selected as a case study. For the damaged bridges, data such as level of damage, material used in these bridges, type of bridge (girder/precast/in situ), age of the bridge, elevation of the bridge from the mean sea level, annual average daily traffic, class of the bridge, heavy vehicles and inspection data before and after the flood were collected and analysed. The attributes of bridges contributing to failure such as bridge approaches, bridge surface, waterway, bridge substructure and bridge superstructure were identified and further analysis is undertaken on the failure criteria/mode of failure of different types of bridges (concrete, timber, in situ, pre-cast, etc.). It was interesting to observe that there is an unexpected inverse relationship between the age of the bridge and the damage level, as well as the daily traffic and the damage level. The reasons for this is further investigated and attributed to the different construction practices adopted in different periods of construction, previous rehabilitation work or road classification and loading adopted in the design of road structures. To analyse and confirm these reasons, bridge design codes used for the bridges in question have been identified and analysed.
