@article {bnh-7480, title = {Structural design of floodways under extreme flood loading}, journal = {International Journal of Disaster Resilience in the Built Environment}, volume = {11}, year = {2020}, month = {05/2020}, abstract = {

Purpose

Current methods for floodway design are predominately based on hydrological and hydraulic design principles. The purpose of this paper is to investigate a finite element methods approach for the inclusion of a simplified structural design method into floodway design procedures.

Design/methodology/approach

This research uses a three-dimensional finite element method to investigate numerically the different parameters, geometric configurations and loading combinations which cause floodway vulnerability during extreme flood events. The worst-case loading scenario is then used as the basis for design from which several structural design charts are deduced. These charts enable design bending moments and shear forces to be extracted and the cross-sectional area of steel and concrete to be designed in accordance with the relevant design codes for strength, serviceability and durability.

Findings

It was discovered that the analysed floodway structure is most vulnerable when impacted by a 4-tonne boulder, a 900 mm cut-off wall depth and with no downstream rock protection. Design charts were created, forming a simplified structural design process to strengthen the current hydraulic design approach provided in current floodway design guidelines. This developed procedure is demonstrated through application with an example floodway structural design.

Originality/value

The deduced structural design process will ensure floodway structures have adequate structural resilience, aiding in reduced maintenance and periods of unserviceability in the wake of extreme flood events.

}, keywords = {bridge failure, Flood, floodways, impact load, Infrastructure, resilience}, doi = {https://doi.org/10.1108/IJDRBE-10-2019-0072}, url = {https://www.emerald.com/insight/content/doi/10.1108/IJDRBE-10-2019-0072/full/html?skipTracking=true}, author = {Isaac Greene and Weena Lokuge and Warna Karunasena} } @article {bnh-6868, title = {Vulnerability assessment of bridges subjected to extreme cyclonic events}, journal = {Natural Hazards}, year = {2020}, month = {04/2020}, abstract = {

Over the past few years, Queensland in Australia has suffered from a number of severe tropical cyclones, the most recent one being Marcia, which took place in 2015. Damage bill of Cyclone Marcia exceeded $50 million which included the cost of repairing a number of damaged road structures. Failure of road structures such as bridges isolates communities from accessing essential services and commodities. This necessitated a methodical approach to evaluate the failure of bridges to improve their resilience and provide base knowledge for developing emergency maintenance response. Although there are several methods available to evaluate the vulnerability of bridges, fault tree analysis (FTA) was selected in this study by considering its positive attributes over the other methods. FTA was used to estimate the probabilities of failure of main components (superstructure and substructure) and elements of timber and concrete bridges. Secondary data (level 1 and level 2 bridge inspection reports from Transport Main Roads in Rockhampton) before and after the Cyclone Marcia were used in conjunction with expert advice to construct fault trees for both timber and concrete bridges. Potential failure mechanisms were observed, and the degree of susceptibility of main components of timber and concrete bridges to cyclonic events was evaluated. This research was based on selected bridges under specific cyclone in one region, which is a limitation of the study. Few other case study bridges subjected to cyclonic events can be used to strengthen the understanding of the complete dynamics of the bridge failure under these extreme events.

}, keywords = {bridge failure, cyclone, fault tree analysis, preventative maintenance, Vulnerability}, doi = {https://doi.org/10.1007/s11069-020-03931-y}, url = {https://link.springer.com/article/10.1007/s11069-020-03931-y$\#$citeas}, author = {Thilini Pathiranage and Weena Lokuge} } @article {bnh-6040, title = {Predicting the probability of failure of timber bridges using fault tree analysis}, journal = {Structure and Infrastructure Engineering}, volume = {15}, year = {2019}, month = {02/2019}, pages = {783-797}, abstract = {

The resilience of a community in an extreme event depends mainly on the robustness of the critical infrastructures. Road bridges are a critical link of the road network, which plays a focal role in Australia{\textquoteright}s economy, prosperity, social well-being and quality of life. Timber bridges are a weaker link of the Australian road network and they often provide critical access to the rural communities. This research uses a number of bridge inspection reports to develop a method to predict the probability of failure of a timber bridge. The inspected condition states of the elements in the timber bridge are used to develop a Markov chain based model and Gamma process model to predict the deterioration of each element. The probability of condition state movement for each element thus calculated were used in fault tree analysis to estimate likelihood of failure of a bridge in a given time period. Although the developed method is based on limited data and it has several limitations, model can be further refined with the availability of more inspection reports. The method developed is demonstrated using an inspection report for a timber bridge, which was not used in the development of the models.

}, keywords = {bridge failure, fault tree analysis, inspection, Markov process, rehabilitation, Timber structures}, doi = {https://doi.org/10.1080/15732479.2019.1569069}, url = {https://www.tandfonline.com/doi/abs/10.1080/15732479.2019.1569069}, author = {Weena Lokuge and Matthew Wilson and Huu Tran and Sujeeva Setunge} }