Development of an optimum maintenance strategy for infrastructure

Worldwide, due to aging of vast asset of infrastructure, effective maintenance of infrastructures is increasingly sought by asset managers. In an ageing infrastructure, various potential deficiencies i.e. failure modes can cause failure and consequently economic losses. Through an effective maintenance strategy, the catastrophic failures of structures can be prevented. In this paper, an efficient maintenance strategy considering different failure modes and structural components, which determines when, where and what to maintain, is developed. Within this maintenance strategy, time-dependent reliability as well as structural system reliability is employed. After mathematical formulation of the proposed maintenance strategy, in an example, application of the proposal to a bridge structure is presented. © 2017 Taylor & Francis Group, London

Development of an optimum maintenance strategy for infrastructure

Worldwide, due to aging of vast asset of infrastructure, effective maintenance of infrastructures is increasingly sought by asset managers. In an ageing infrastructure, various potential deficiencies i.e. failure modes can cause failure and consequently economic losses. Through an effective maintenance strategy, the catastrophic failures of structures can be prevented. In this paper, an efficient maintenance strategy considering different failure modes and structural components, which determines when, where and what to maintain, is developed. Within this maintenance strategy, time-dependent reliability as well as structural system reliability is employed. After mathematical formulation of the proposed maintenance strategy, in an example, application of the proposal to a bridge structure is presented. © 2017 Taylor & Francis Group, London

Time-dependent finite element reliability assessment of cast-iron water pipes subjected to spatio-temporal correlated corrosion process

© 2020 Reliable prediction of the service-life of water pipes is of great importance for asset managers and decision makers. This paper introduces a framework for evaluating the reliability of corroded pipelines. Incorporating the random field representation of corrosion into a finite-element analysis have always been a daunting task especially when the time-dependent reliability analysis is intended. This research addresses the issue by representing the cross-section reduction of a buried pipe due to corrosion through a combination of the Gamma process concept and copula. Moreover, spatial and temporal evolutions of the correlation structure that exists among the corrosion pits over the pipe surface are considered using a time-dependent correlation length model recently introduced by the authors. A three-dimensional non-linear finite element analysis is used to model the residual strength of pipes in terms of time. The method is applied to a case study for estimating the failure probability of a corrosion-affected cast iron water pipe. Furthermore, the impact of the correlation structure of the corrosion depths on the estimated probability of failure is investigated. The research concludes that the proposed method is able to predict the service life of corroding buried pipeline efficiently

Risk-cost optimised maintenance strategy for tunnel structures

Due to limited maintenance budget, effectively spending the available funds for maintaining infrastructures is increasingly sought by asset managers. Tunnel is an essential infrastructure that plays a pivotal role in transportation network, economy, prosperity, social well-being, quality of life and the health of its population. In the light of considerable research that has been or is being undertaken on "aboveground" infrastructure, e.g. bridges, this threat cannot be more apparent for underground infrastructure such as tunnels. The situation has been exaccrbatcd due to more unknowns and uncertainties relating to the factors such as underground water and soil/rock that affect the operation of tunnel infrastructure. In an ageing tunnel system, various potential deficiencies such as seepage, spalling, crack, delamination, steel corrosion, drainage, convergence and settlement of the lining structure can cause catastrophic life safety and economic consequences. Most collapses of tunnel structures in the world are related to tunnel deterioration with catastrophic consequences. Through an effective maintenance plan, the catastrophic failures of tunnels can be prevented. This research aims to develop a maintenance strategy for concrete tunnels which determines when (maintenance intervention times), where (segments of tunnel network) and what (failure mode of tunnel structure) maintenance actions need to be taken to ensure the safe and serviceable operation of tunnel with the intention to minimise the risk. The mathematical formulation of the proposed maintenance strategy, which is based on risk optimisation, is provided in a generic format. Application of the proposal to tunnel structures is presented in a numerical example. © The authors and ICE Publishing: All rights reserved, 2016

Risk-cost optimised maintenance strategy for tunnel structures

Due to limited maintenance budget, effectively spending the available funds for maintaining infrastructures is increasingly sought by asset managers. Tunnel is an essential infrastructure that plays a pivotal role in transportation network, economy, prosperity, social well-being, quality of life and the health of its population. In the light of considerable research that has been or is being undertaken on "aboveground" infrastructure, e.g. bridges, this threat cannot be more apparent for underground infrastructure such as tunnels. The situation has been exaccrbatcd due to more unknowns and uncertainties relating to the factors such as underground water and soil/rock that affect the operation of tunnel infrastructure. In an ageing tunnel system, various potential deficiencies such as seepage, spalling, crack, delamination, steel corrosion, drainage, convergence and settlement of the lining structure can cause catastrophic life safety and economic consequences. Most collapses of tunnel structures in the world are related to tunnel deterioration with catastrophic consequences. Through an effective maintenance plan, the catastrophic failures of tunnels can be prevented. This research aims to develop a maintenance strategy for concrete tunnels which determines when (maintenance intervention times), where (segments of tunnel network) and what (failure mode of tunnel structure) maintenance actions need to be taken to ensure the safe and serviceable operation of tunnel with the intention to minimise the risk. The mathematical formulation of the proposed maintenance strategy, which is based on risk optimisation, is provided in a generic format. Application of the proposal to tunnel structures is presented in a numerical example. © The authors and ICE Publishing: All rights reserved, 2016