Journals
Time-Dependent Reliability Analysis of Buried Water Distribution Network: Combined Finite-Element and Probabilistic Approach
ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering, 7(4), 04021064.
Corrosion deterioration is the predominant factor for a large number of cast iron (CI) water main breaks. The reliability of CI pipelines decreases overtime as corrosion growth on pipe walls significantly reduces the strength of pipeline materials. To predict the reliability of water pipelines accurately, this study used a finite-element analysis (FEA) approach to determine the maximum pipeline stress at various stages of the pipeline’s life. A series of FEAs was performed to consider uncertainties in parameters associated with stress analysis. The circumferential stress was found to be the most critical stress for pipelines. Time-variant circumferential stress was obtained by accounting for the time-dependent corrosion pit growth on the pipeline wall. The time-variant failure probability of pipelines was determined by comparing the circumferential stress and the tensile failure strength of the pipeline at the burst limit state.
2021
Asset Management Decision Support Model for Water Distribution Systems: Impact of Water Pipe Failure on Road and Water Networks
Journal of Water Resources Planning and Management, 147(5), 04021022.
Failure of a buried water pipeline can have an adverse effect on neighboring infrastructure,especially road networks. The impact of the failure of water pipelines on road networks and water distribution systems (WDSs) significantly increases the economic and social consequences of such failure. This paper presents a risk-informed decision support framework for WDSs considering the risk and the criticality of components to aid maintenance prioritization.
2021
Failure Risk Analysis of Pipelines using Data-Driven Machine Learning Algorithms
Journal of Structural Safety, 89, 102047.
Failure risk analysis of pipeline networks is essential for their effective management. Since pipeline networks are often large and complex, analyzing a large number of pipelines is often intensive and time-consuming. This study utilizes recent advances in machine learning to develop a viable alternative to computationally intensive analytical approaches to determine the failure risk of steel oil and gas pipelines. Burst failure risk of pipelines under active corrosion defects is evaluated considering the remaining strength of pipelines with corrosion pit.
2021
Post-Disaster Sequential Recovery Planning for Water Distribution Systems using Topological and Hydraulic Metrics
Journal of Structure and Infrastructure Engineering.
Multiple pipeline failures in water distribution systems (WDS) caused by natural hazards such as earthquakes can significantly reduce the functionality of the systems. After a natural disaster, a quick recovery of WDS is desirable to ensure that critical facilities have access to clean water. However, experience from recent disasters has shown that the recovery period for WDS can be long. The recovery period depends on various factors, such as available resources, budget, etc. As such, all the failed pipelines cannot be repaired at the same time....
2021
Framework for Seismic Damage and Renewal Cost Analysis of Buried Water Pipelines.
ASCE Journal of Pipeline Systems - Engineering and Practice, 11(4), 04020038.
Buried water pipelines suffer extensive damages when subjected to earthquake loading. Probable seismic damage of buried pipelines is typically estimated based on empirical analyses, where the effects of corrosion deterioration are often neglected. Corrosion induced deterioration weakens the pipeline resistance capacity, which in turn significantly reduces the seismic reliability of water distribution systems (WDS). Improved seismic damage estimation of buried water pipelines needs to consider the effect of corrosion on their seismic performance to assist with the development of an effective and efficient renewal strategy. Hence, the first part of this study improves the American Lifeline Alliance (ALA) 2001 guideline on seismic repair rate (RR) estimation, based on the observed effects of corrosion on pipeline damages during a recent earthquake (2014 Napa Earthquake).
2020
Evaluation of natural hazard risk for coastal districts of Bangladesh using the INFORM approach.
International Journal of Disaster Risk Reduction.
Coastal districts of Bangladesh are increasingly suffering from climatic hazards (e.g., cyclone, flood, saltwater intrusion). Tropical cyclones and floods particularly affect millions of people almost every year. Massive property damages and life losses are a common scenario when these disasters hit the coastal belt. Moreover, due to climate change impact, saltwater intrusion is increasing significantly in the coastal districts, especially during dry seasons impacting crop production and drinking water sources. The amount of asset and population exposed to natural hazards have increased significantly in the coastal belt, which has exacerbated the risk of natural hazards. Previous studies on the disaster risk of coastal districts of Bangladesh did not explicitly account for the key vulnerability and lack of coping capacity parameters that are crucial for a comprehensive risk assessment. This study assesses the disaster risk of 19 coastal districts of Bangladesh using the Index for Risk Management (INFORM) model.
2020
Seismic Functionality and Resilience Analysis of Water Distribution Systems.
ASCE Journal of Pipeline Systems - Engineering and Practice, 11(1): 04019045..
Buried water pipelines are subjected to corrosion deterioration and are vulnerable to extreme events (e.g. earthquakes). Corroded metallic buried pipelines have experienced severe damage during past earthquakes resulting in the service disruption of Water Distribution System (WDS). Also, continuous and adequate water supply is imperative for fighting fires caused by the earthquakes. Therefore, evaluation of the functionality of WDS and its service restoration after an earthquake is very important for the water service provider as well as the communities. This paper presents a framework to evaluate both component-level and system-level seismic risk and resilience of WDSs considering time-variant corrosion of pipelines. The vulnerability of individual pipelines is modelled by modifying the American Lifelines Alliance (ALA) pipeline vulnerability functions to explicitly account for the strength deterioration due to corrosion. Resilience is modelled using a functionality curve that relates system failure probability and repair activities over time. Probabilistic Functionality Fragility Surface (FFS) is developed for both components and system, by integrating the fragility curves and the restoration functions. The use of the proposed framework is demonstrated on two hypothetical water networks (i.e., one small scale and one medium scale).
2019
Reliability Analysis of Water Distribution Systems using Physical Probabilistic Pipe Failure Method.
ASCE Journal of Water Resource Planning and Management 145(2): 04018097
Water distribution systems (WDS) are among the most essential infrastructure systems for the sustenance of societies. Therefore, their continued reliability is of utmost importance. However, the reliability of WDSs decreases over time due to aging and deterioration of components, especially pipelines. Metallic pipes are subject to external and internal corrosion overtime, which can significantly affect their mechanical strength and hydraulic performance and, consequently, WDS reliability. Existing research on system reliability is typically based on statistical failure prediction of pipelines, which, however, typically assumes a constant failure rate, thereby ignoring time-dependent strength deterioration due to corrosion. This paper proposes a framework for modeling the time-dependent reliability of WDSs with cast iron pipes considering both mechanical and hydraulic reliabilities.
2018
Performance Evaluation of Water Distribution Systems and Asset Management.
ASCE Journal of Infrastructure Systems 24(3):03118001
Water distribution systems (WDS) are among the most critical civil infrastructure systems. A reliable and safe water supply is essential for the prosperity and continued well-being of society. Hence, adequate maintenance, repair, and renewal of the vast physical assets in WDS are of paramount importance, especially in places with widespread deterioration of critical water infrastructure assets. However, due to limited resources, water utilities struggle for their asset management strategies to keep pace with the aging of components. Recently, utilities have made efforts to refine the traditional condition-based approach to pipeline asset management that focuses on maintaining the current condition of assets into a service-based approach in which system performance is explicitly considered. This paper reviews existing literature on the various aspects of asset management of WDS, focusing specifically on buried pipelines. Existing condition assessment (CA) techniques, failure prediction models, time-dependent vulnerability models, maintenance planning strategies, and renewal techniques are reviewed.
2018
Seismic Damage Assessment Using GIS and RADIUS: A Case Study of Sylhet City, Bangladesh.
International Journal of Disaster Risk Reduction 34:243-254.
Seismic risk of urban areas around the world is a major concern to stakeholders due to the potential losses of lives and extensive damage to infrastructure that can occur following an earthquake. As risk mitigation resources are limited, a method for assessing risk and prioritizing structures for seismic retrofit at a city or regional scale is required. Scenario-based seismic damage prediction can be used by decision-makers for identifying the riskiest structures that can be prioritized for risk mitigation to optimize the use of available resources. In this case study, for the first time, seismic damage estimation is performed for Sylhet City Corporation (SCC), Bangladesh by integrating Risk Assessment tools for Diagnosis of Urban areas against Seismic disasters (RADIUS) and Geophysical Information System (GIS).
2018
Analytical Fragility Curves for Reinforced Concrete Building Using Single Point Scaled Spectrum Matched Ground Motion Analyses.
Malaysian Journal of Civil Engineering 28(3):394-406.
Seismic performance is obtained for a five-storied reinforced concrete frame building performing non-linear dynamic time history analyses. Performance of the building was obtained as a mean of fragility function of spectral acceleration. Earthquake ground motion records are selected from online source considering local earthquake faults scenario proposed in Comprehensive Disaster Management Program (CDMP) and then scaled to fit with Bangladesh National Building Code (BNBC) 1993 design response spectra. Since the structure is considered as typical reinforced concrete ordinary moment resisting frame located in Bangladesh, mechanical properties and other associated parameters are chosen according to Bangladeshi perspective. Each ground motion spectrum is matched with design code spectrum at fundamental time period of the building.
2016
Conference Papers
Reliability Assessment of Corroded Water Distribution Networks.
ASCE-UESI Pipelines Conference, Nashville, TN 2019.
A majority of water mains in North America are made of cast iron (CI). The use of CI pipes in water utility started at the end of the nineteenth century and many of the pipes are still functioning even after their expected lifespan. CI pipelines are susceptible to external and internal corrosion over time, which can significantly affect their mechanical strength and hydraulic performance, and consequently the water distribution system (WDS) reliability. Buried CI water mains have experienced the highest number of failures due to corrosion deterioration over time. Since most of the water pipelines are running underground, physical condition assessment of pipelines in a distributed network is often expensive and time-consuming. Existing research on WDS reliability based on statistical failure prediction methods typically assume a constant failure rate and ignore time-dependent strength change due to corrosion.
2019
A Decision-making Framework for Water Distribution Systems using Fuzzy Inference and Centrality Analysis.
International Conference on Applications of Statistics and Probability in Civil Engineering, Seoul, Korea 2019.
Water Distribution Systems (WDSs) are among the most important infrastructures that are critical for the smooth functioning of communities. However, age-old existing WDSs are progressively at risk in the United States. Since failure in a WDS may affect other interdependent infrastructure and result in high economic consequences, water utilities are more interested in preventing rather than reacting to failure. The current study proposes a decision support framework that employs fuzzy hierarchical inference and network graph analysis to rank the most vulnerable water pipelines considering a set of risk factors and their negative consequences. Fourteen (14) risk factors are identified considering water and road network interdependence.
2019
Conference Poster
Risk and Resilience of Aging Water Distribution Systems.
ASCE Structures Congress, Fort Worth, TX 2018.
A majority portion of Water Distribution System (WDS) mains are in North America is made of Cast Iron. Use of CI material in water utility started at the end of the nineteenth century and still functioning in many municipalities even after their expected lifetime. CI pipelines are subjected to external and internal corrosion overtime, which can significantly affect their mechanical strength and hydraulic performance, and consequently the WDS reliability. Buried CI water pipelines have experienced the highest number of failures due to corrosion deterioration over time. Since most of the water pipelines are running underground, physical condition assessment of pipelines in a distributed network is often expensive and time-consuming. On the other hand, existing research based on statistical failure prediction method typically assumes a constant failure rate and ignore time-dependent strength change due to corrosion.