74 research outputs found
Influence of Decision Making During Disasters and How It Impacts a Community
The frequency of natural disasters occurrences has increased and is becoming noticed by many due to the impact on economy, society, and the environment.
Decision making during disasters contributes towards community safety and resilience. Decisions taken to protect people from disasters have an impact on society, economy, environment, travel patterns, and reliability and performance of transport networks.
Decisions often affect the performance of transport networks and critical infrastructure systems during disasters and during demand times. Decision making and decision styles which were observed during disaster events will show the areas that the decisions have worked well or created more risks to the society. Risks to the community due to environmental disasters are high, and they are worsened when integrated with poor decision making and actions. Good decision making provides for community resilience, good connectivity between cities, improved efficiency, safety to communities, and improved network reliability to all road users during disasters.
This paper will examine decision-making scenarios used during disasters and how they impacted the community and provided for community resilience. The case study will identify ways to integrate decision making into disaster risk reduction and shows the decisions made during extreme events and how they impacted on the community and transport infrastructure
Design of Ternary Blend High-Volume Fly Ash Concrete Mixes using Hydrated Lime
The increase of carbon emission due to annual growth of Portland cement (PC) production has enforced research into the development of sustainable green concrete using a range of readily available industrial waste materials. The present study is focused on developing two high volume fly ash (HVFA) concretes with cement replacement levels 65% (HVFA‒65) and 80% (HVFA‒80). Initially, the required lime for both HVFA concrete mixes were determined, and then the optimized mix design identified, based on 28-day strength, by varying the fly ash‒lime combination. The optimized mixes achieved a compressive strength of 53MPa and 40MPa, for HVFA‒65 and HVFA‒80 concretes, respectively. Similar to PC concrete, both HVFA concretes showed high resistance to chloride penetration, water absorption and carbonation at 28 days. The early stage strength development is dependent upon the matrix produced in the specific HVFA concrete, which is itself dependent upon the number of unreacted fly ash spheres
Investigating the performance of floodway in an extreme flood event
Resilience of critical infrastructure such as roads, telecommunications and power is vital in support activities for disaster response and recovery. In the event of natural disasters such as the Queensland floods, resilient roads were critical to survival and safety, as well as to the health and security of the region. Disaster damage to road structures such as bridges, culverts and floodway significantly increases the vulnerability of communities. This research paper investigates the damage caused by the recent floods in Queensland on the floodway. Floodway in Lockyer Valley Regional council (LVRC) area in Queensland has been selected as a case study. LVRC has identified a major need to re-examine the design of flood-ways, which have to be designed to be submerged during a flood and return to complete functionality after the flood water subsides. In 2011 flood, about 58% of the floodway were damaged in LVRC area. Many of the flood-ways were damaged during the period of submergence and are currently the weakest links in Lockyer Valley roads after a flood. There are no standard design guidelines for these structures accepted at national level.
In this case study, data such as the dimensions, materials used (concrete, gravel with concrete overlay), culvert details and the type of road where the floodway are situated will be collected. Inspection of damaged floodway revealed that the damage due to the floods was mainly due to the excessive debris load and impact load. This paper aims at developing a strategy for flood-way design considering impact loading and debris loading by using a detailed analysis of flood-ways in this region
Using Shipping Containers to Provide Temporary Housing in Post-disaster Recovery: Social Case Studies
AbstractHousing that makes use of the ubiquitous general purpose shipping container is becoming more commonly seen as a useful way of reusing the empty vessels as valuable accommodation. In particular, the application of shipping container temporary housing is suited to post-disaster situations, design examples of which can be found in the literature. However, ensuring the success of implementing such projects in a post-disaster setting requires investigation into the social considerations of temporary housing. This research takes a qualitative approach, focusing particularly on case studies of temporary housing experiences following the Hurricane Katrina in 2005, the Christchurch Earthquake in 2011 and a field study of 2009 Black Saturday bushfire-affected communities in Victoria, Australia. Key social factors found to be significant to the success of shipping container temporary housing projects relate to flexibility in ownership, reuse and siting arrangement, in addition to robust pre-disaster planning by authorities, taking into account the varying characteristics of different types of disasters
Framework to inspect floodways towards estimating damage
Floodways provide economic and environmental friendly alternative solution over bridges and culverts for roads with low traffic volumes in rural road networks. They connect regional communities, farmlands and agricultural areas to city centers and hence play a vital role in the economy of a country. Design and operational condition of floodways differ from major road infrastructures because the floodway design process allows a certain degree of submergence for floods with high annual exceedance probability (AEP). Nevertheless, natural hazards can cause damage to floodways as evident from the 2011 and 2013 Queensland flood events. 58% of floodway structures in the Lockyer Valley Regional Council area in Queensland, Australia, were damaged during the 2013 Queensland flood event leading to operational failures in rural road networks and isolating regional communities. Damage assessment during the post-disaster event is a difficult but significant step to enhance the resilience of regional communities. A lack of a proper method to estimate the extent of damage can cause significant delays to repair/reconstruction activities and also can lead to errors in the decision-making process on prioritizing the repair/reconstruction works. Such delays can have a detrimental effect on the resilience of the regional communities. In general, floodways are infrequently being inspected or assessed its capacity only after a natural disaster. This irregularity can cause difficulties during the inspection and assessment process, as information on the previous state of the floodway can easily be unknown. Unavailability of a widely accepted inspection framework is the main cause of this problem. Having identified this gap in knowledge, this paper aims to develop a floodway inspection framework. This framework is designed to extend its capability to help the decision makers to quantify the damage and estimate the repair/reconstruction needs. This framework, therefore, contributes to enhancing the resilience of regional communities who are served by floodways
Fault tree analysis method for deterioration of timber bridges using an Australian case study
Purpose:
Deterioration of timber bridges can often be related to a number of deficiencies in the bridge elements, connectors and or as a result of been in aggressive environments which they are exposed to. The maintenance cost of timber bridges is affected significantly by a number of deterioration mechanisms which require a systematic approach for diagnosis and treatment. Evaluating the risk of failure of these bridges is of importance in bridge performance assessment and decision making to optimize rehabilitation options.
Design/ methodology/ approach:
This paper identifies common causes for timber bridge deterioration and demonstrates an integrated approach based on fault tree analysis (FTA) to obtain qualitative or quantitative estimation of the risk of failure of timber bridge sub-systems. Level 2 inspection report for a timber bridge in Queensland, Australia has been utilized as a case study in this research to identify the failure modes of the bridge.
Originality/ value:
A diagnostic tool for timber bridge deterioration will benefit asset inspectors, managers, and engineers to identify the type, size and the distress mechanisms in order to recognize the proper corrective measures either to prevent or to reduce further deterioration. Timber bridge maintenance is a major issue in Queensland, Australia. The proposed framework can benefit road authorities and local councils
Prioritising sustainability factors for Australian community buildings’ management using Analytical Hierarchy Process (AHP)
The essence of Australian community buildings’ sustainable management drives through a previously established decision-making structure with four sustainability aspects and accompanying 18 criteria. Informed decisions are supported with a decision-making model that generates sustainability impacts of building components based on this decision-making structure. Building components’ individual impacts can be assigned using a numbering scale incorporated with linguistic terms. However, similar importance given to each aspect or criterion is arguable when the combined effect is considered. Hence, they should be given different weightings and their combination with individual impacts will produce final sustainability impacts. For calculating weightings, the study uses Analytical Hierarchy Process (AHP), widely used technique in Multi Attribute Decision-Making (MADM). The study also conducted an industry-wide questionnaire across Australian local councils because pair-wise comparison data is essential for weighting calculation. This paper presents the survey data and analysis results that captured weightings of sustainability aspects and criteria
Strategies for minimising the whole of life cycle cost of reinforced concrete bridge exposed to aggressive environments
n design of bridge structures, it is common to adopt a 100 year design life. However, analysis of a number of case study bridges in Australia has indicated that the actual design life can be significantly reduced due to premature deterioration resulting from exposure to aggressive environments. A closer analysis of the cost of rehabilitation of these structures has raised some interesting questions. What would be the real service life of a bridge exposed to certain aggressive environments? What is the strategy of conducting bridge rehabilitation? And what are the life cycle costs associated with rehabilitation? A research project funded by the CRC for Construction Innovation in Australia is aimed at addressing these issues. This paper presents a concept map for assisting decision makers to appropriately choose the best treatment for bridge rehabilitation affected by premature deterioration through exposure to aggressive environments in Australia. The decision analysis is referred to a whole of life cycle cost analysis by considering appropriate elements of bridge rehabilitation costs. In addition, the results of bridges inspections in Queensland are presente
Evaluation of distress mechanisms in bridges exposed to aggressive environments.
There are about 2500 bridges in Queensland, Australia. Majority of these structures require significant repairs around the halfway mark of their design life with probably 1% or less reaching a 100 year design life. (Carse, 2005). This is due to the fact that bridges constructed in aggressive environments such as the coastal regions experience accelerated deterioration. As a result, maintaining the service delivery of these assets has become one of the important issues for the Queensland Department of Main Roads (QDMR)
Towards a rule-based matrix for evaluating distress mechanisms in bridges
The effective management of bridge stock involves making decisions as to when to repair, remedy, or do nothing, taking into account the financial and service life implications. Such decisions require a reliable diagnosis as to the cause of distress and an understanding of the likely future degradation. Such diagnoses are based on a combination of visual inspections, laboratory tests on samples and expert opinions. In addition, the choice of appropriate laboratory tests requires an understanding of the degradation mechanisms involved. Under these circumstances, the use of expert systems or evaluation tools developed from “realtime” case studies provides a promising solution in the absence of expert knowledge. This paper addresses the issues in bridge infrastructure management in Queensland, Australia. Bridges affected by alkali silica reaction and chloride induced corrosion have been investigated and the results presented using a mind mapping tool. The analysis highights that several levels of rules are required to assess the mechanism causing distress. The systematic development of a rule based approach is presented. An example of this application to a case study bridge has been used to demonstrate that preliminary results are satisfactory
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