Showing papers in "Structure and Infrastructure Engineering in 2018"

Abstract: Unmanned aerial vehicles (UAV) are now a viable option for augmenting bridge inspections. Utilising an integrated combination of a UAV and computer vision can decrease costs, expedite inspections a...

Abstract: Pipe failure modelling is an important tool for strategic rehabilitation planning of urban water distribution infrastructure. Rehabilitation predictions are mostly based on existing network data and historical failure records, both of varying quality. This paper presents a framework for the extraction and processing of such data to use it for training of decision tree-based machine learning methods. The performance of trained models for predicting pipe failures is evaluated for simple as well as more advanced, ensemble-based, decision tree methods. Bootstrap aggregation and boosting techniques are used to improve the accuracy of the models. The models are trained on 50% of the available data and their performance is evaluated using confusion matrices and receiver operating characteristic curves. While all models show very good performance, the boosted decision tree approach using random undersampling turns out to have the best performance and thus is applied to a real world case study. The applicability of decision tree methods for practical rehabilitation planning is demonstrated for the pipe network of a medium sized city.

Abstract: Conventional water pipeline leak detection surveys employ labour-intensive acoustic techniques, which are usually expensive and not amenable for continuous monitoring of distribution systems. Many ...

Abstract: A non-linear finite element (FE) framework for time-dependent capacity assessment of corroded rectangular reinforced concrete (RC) columns is developed. The proposed non-linear FE model includes th...

Abstract: This is an Accepted Manuscript of an article published by Taylor & Francis Group in Structure and Infrastructure Engineering on 2018, available online at: http://www.tandfonline.com/10.1080/15732479.2018.1438479

Abstract: The loss of infrastructure functionality for a community from a tornado can significantly affect economic vitality and result in substantial social disruption. The duration of the loss of functionality is a decisive factor in the magnitude of the economic disruption caused by a tornado. Therefore, quantitative models for the post-tornado restoration processes are needed in order to provide risk-informed decision support. In this study, the water network, electric power network, school buildings, residential buildings and businesses were modelled with their relative spatial distribution along with select dependencies and cross-dependencies in order to investigate the restoration of a community in the aftermath of a disaster. A tornado path was simulated using statistics from a historical tornado database. Based on the damage level of the components and their connectivity throughout the community, the functionality of the supplier nodes was assessed through a Monte Carlo simulation. Finally, the rep...

Abstract: Existing performance models developed for interurban pavements are not applicable to urban pavements due to differences in traffic demands and deterioration trends. The objective of the study was t...

Abstract: This paper presents a method to analyse the influence of multi-pier settlement on the train–track–bridge coupled dynamic system, and to determine the safe value of the continuous multi-pier settlem...

Abstract: The main objective of this work is to develop a comprehensive criteria-based multi-attribute decision-making model to plan the rehabilitation of water networks. Among the main features of this model is the capability to simultaneously analyse comprehensive criteria for the rehabilitation of water networks; where there is a significant uncertainty within the operational data. In this model, which is called as WDSR model, using a fuzzy TOPSIS technique, it is possible to adjust the criteria based on the local conditions, and to weight them based on the group decision-making of experts. In this paper, using the WDSR model, the rehabilitation plan of the ‘Anytown’ water network is prioritised through two methods. The first method uses a predefined template of WDSR, and the second uses a local template based on the conditions within the study area. The obtained results show the potential of the WDSR in the rehabilitation planning of water networks, where is encountered with numerous criteria, a signifi...

Abstract: The selection and use of technical parameters and performance indicators plays an essential role in the pavement management process. It is known that if more parameters are used, a more accurate ev...

Abstract: A significant number of old masonry bridges are still in use and need to be assessed considering current traffic loading and safety requirements Masonry bridges are complex heterogeneous systems,

Abstract: This paper presents a computational framework for risk-based planning of inspections and repairs for deteriorating components. Two distinct types of decision rules are used to model decisions: simp...

Abstract: Many areas of the world are prone to multiple hazards that can be concurrent/non-concurrent and dependent/independent. Infrastructure systems located in such areas will likely be subjected to more ...

Abstract: This paper presents a framework for life-cycle loss estimation for non-structural damage in tall buildings under wind and seismic loads. Life-cycle cost analysis is a useful design tool for decisio...

Abstract: This paper estimates visual inspection quantitatively prior to its implementation in a Bridge Management System using a Value of Information (VoI) approach employing a Bayesian pre-posterior analysis. Information from a significant number of real bridges from Ireland and Portugal are considered in this regard following existing commercial practices. The variation of different parameters on the estimated VoI is investigated including the assumed probabilistic models of the prior bridge state, the likelihood of inspector assigned condition ratings and the economic setting surrounding the cost matrix for maintenance decision alternatives. The values of no information, perfect information and imperfect information are presented and the change in the optimal strategy based on such information is assessed. The effect of human imperfections in assessment and difference in condition rating scale are also estimated. The studies and findings of this paper are expected to allow a better insight for practisin...

Abstract: Addressing the multidimensional challenges involved in advancing the sustainability of pavement systems requires the development of optimisation-based decision support system (DSS) for pavement management with the capability to identify optimally sustainable pavement maintenance and rehabilitations (M&R) strategies. The main objective of this research work is to develop a multi-objective optimisation framework that hosts a comprehensive and integrated pavement life cycle costs–life cycle assessment model that covers the pavement’s whole life cycle, from the extraction and production of materials to construction and maintenance, transportation of materials, work-zone traffic management, usage and end-of-life. The capability of the proposed DSS is analysed in a case study aiming at investigating, from a full life cycle perspective, the extent to which a number of pavement engineering solutions are efficient in improving the environmental and economic aspects of pavement sustainability, when applied ...

Abstract: Civil infrastructure assets, such as roads, locks, bridges, treatment plants and storm surge barriers, are often characterised by long service lives and corresponding technical life cycles. When life cycles are long, the time value of money plays a role in asset management decision-making on capital investments and operation and maintenance expenditures. In this paper, a new life cycle costing (LCC) approach for discounting in two classes of maintenance optimisation models is developed. These models are the age replacement model and the interval replacement model. Three well-known LCC techniques, which are the present worth, the capital recovery and the capitalised equivalent worth, are combined and used to develop a stepwise methodology. This methodology is validated with the few case-specific mathematical equations that exist in the literature. The advantage of using this alternative LCC approach is its applicability and flexibility for reliability and maintenance engineers. The resulting LCC method builds on well-known LCC formula and enhances the understanding of the inclusion of discounting principles in reliability models. Understanding these principles makes the method flexible. Practitioners can extend or adapt the method to changing circumstances, such as additional cash flows and altering reliability modelling.

Abstract: Chloride-induced corrosion of highway bridges constitutes a critical form of environmental deterioration and may result in significant escalation of seismic life-cycle costs due to increased fragil...

Abstract: The International Association for Life-Cycle Civil Engineering (IALCCE) was founded in 2006 to support this challenge and to create a fertile ground for promoting the study, research, and applicati...

Abstract: An overview of structural integrity management of offshore structures in the oil and gas energy sector is presented in this article. Based on relevant experiences with the hazards, accidents and me...

Abstract: Fibre-reinforced plastic (FRP) composites are extensively used to retrofit civil structures. However, the quality and the characteristics of the bond between the FRP and the structure are critical ...

Abstract: This work focuses on structural health monitoring of long span bridges for damage detection. A feature extraction level data fusion based damage isolation strategy is presented using multi-metric sensing. The multi-metric sensing uses two types of sensors, namely strain sensors and accelerometers. The methodology combines the advantages offered by each type of sensors, while at the same time overcomes their limitations. The flexibility index method is applied and the flexibility matrices based on the strain and displacement data are combined after performing co-ordinate transformation. A study has been carried out on a simulated finite element model of the Great Belt East Bridge where realistic damage scenarios like damage in the girder, breaking of hanger cables, pier settlement, and loss of cable pretension were introduced on the structure. The study indicates that multi-metric sensing is indeed necessary as it reduces the possibility of false detections and increases the sensitivity and robustn...

Abstract: The quality of life-cycle assessments and civil and structural engineering reliability analyses depends much on the quality of the models on which they are based. Models for loads and material prop...

Abstract: This study presents the general features of the structural health monitoring (SHM) system of the long-span cable-supported bridges in Turkey, namely the First Bosphorus Bridge, the Second Bosphorus...

Abstract: Full-scale failure tests of bridges are important for improving understanding of bridges’ behaviour and refining assessment methods. However, such experiments are challenging, often expensive, and ...

Abstract: Deterministic seismic analysis of dam-foundation-water does not usually reflect the true behavior of the system due to presence of different epistemic uncertainties. On the other hand, the crude Mo...

Abstract: The Bouc–Wen (BW) model is a successful differential equations model used to describe a wide range of nonlinear hysteretic systems. However, it is unable to describe force degradation, stiffness de...

Abstract: Scheduling of inspection and maintenance policies during the life-cycle of operating infrastructure necessitates optimization of long-term objectives in stochastic environments. Modern answers to t...

Abstract: Ship structures are subjected to repetitive wave loads that can lead to fatigue damage. Accumulation of fatigue damage may eventually result in structural failure. In order to mitigate fatigue haza...

Abstract: In this paper, the effects of soil–structure interaction (SSI) on the response of a girder bridge pier is evaluated by assessing the energy distributions in the barge–pier collision system. The fin...