Papers by Ram Krishna Mazumder
Water Distribution Systems (WDSs) are among the most important infrastructures that are critical ... more 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. These factors are classified into four main vulnerability indices (strength, hydraulic, environmental, road) and one consequence class in order to evaluate the integrated risk of water mains. Fuzzy analytical hierarchy process is used to quantify the uncertainty in the risk factors to aid the decision-making process. Network centrality analysis is used to identify the most critical components of the WDS. The final decision is made by combining the outputs from the fuzzy inference and the network centrality analysis. The WDS of Modena, Italy is used to demonstrate the proposed approach.
Multiple pipeline failures in water distribution systems (WDS) caused by natural hazards such as ... more 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 q...
Seismic performance is obtained for a five-storied reinforced concrete frame building performing ... more 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. Non-linear static pushover analysis is performed to determine damage states from pushover curve. Four damage states (from slight to collapse) are defined bas...
Journal of Building Engineering, 2021
Abstract The seismic risk of old unreinforced masonry (URM) buildings is inherently high due to t... more Abstract The seismic risk of old unreinforced masonry (URM) buildings is inherently high due to their non-ductile behavior. Masonry buildings constructed without seismic resistance characteristics have performed poorly in previous earthquakes. There is a clear need for reliable vulnerability assessment techniques for identifying the most vulnerable buildings to support risk mitigation strategies in urban areas. Seismic risk evaluation and mitigation planning are often performed in a multi-level risk assessment approach, where the first level is meant to identify relatively vulnerable buildings that require further assessment. This paper proposes a fuzzy synthetic-based first level seismic risk evaluation technique for identifying relatively risky URM buildings in an urban area. Fourteen risk factors, categorized into five indexes, are used to estimate the overall seismic risk of individual URM buildings. The proposed approach is illustrated for 81 old URM buildings of an urban settlement at Shakhari Bazar, Dhaka city, Bangladesh, using data collected as part of a technical assessment project by Dhaka City Corporation. The results of the case study show that most of the buildings (more than 90%) have high to a very high level of risk and are expected to suffer severe damage in case of future large earthquakes in this region. The outcome of this study is compared with a previous study conducted for the same urban settlement. The proposed method provides a simple procedure for prioritizing riskiest URM buildings for seismic rehabilitation.
ASCE-ASME Journal of Risk and Uncertainty in Engineering Systems, Part A: Civil Engineering, 2021
AbstractCorrosion deterioration is the predominant factor for a large number of cast iron (CI) wa... more AbstractCorrosion 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 wall...
Journal of Water Resources Planning and Management, 2021
AbstractFailure of a buried water pipeline can have an adverse effect on neighboring infrastructu... more AbstractFailure 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 wate...
International Journal of Disaster Risk Reduction, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Journal of Pipeline Systems Engineering and Practice, 2020
AbstractBuried water pipelines suffer extensive damages when subjected to earthquake loading. Pro... more AbstractBuried water pipelines suffer extensive damages when subjected to earthquake loading. Probable seismic damage of buried pipelines is typically estimated based on empirical analyses, where t...
Journal of Infrastructure Systems, 2018
AbstractWater distribution systems (WDS) are among the most critical civil infrastructure systems... more AbstractWater 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 socie...
It is relatively simple to obtain ground shaking characteristics, i.e. predominant period and amp... more It is relatively simple to obtain ground shaking characteristics, i.e. predominant period and amplification factor, from the microtremor observation in order to estimate the dynamic behaviour of structure for the damage assessment due to future earthquake. The characteristics of ground motion are amplified the most when the frequency content of the motion and the natural frequencies of structure are close to each other. Based on forced and ambient vibration test, the response of surroundings soil as well as structure can be monitored. This paper presents microtremor observations at free-field, concrete floor and on machine foundation in a 110MW power plant site in the south western part of Bangladesh.
Bangladesh is one of the most earthquake prone countries in South Asia where Sylhet City is locat... more Bangladesh is one of the most earthquake prone countries in South Asia where Sylhet City is located. To evaluate the existing condition of Reinforced Concrete Frame Buildings, a multiple level assessment of the seismic vulnerability of 194 Buildings in northern part of Sylhet City, is presented. From the Tier1 assessment, 26% of the buildings performance score was low and 74% of buildings performance score was comparatively good. In Tier 2, it was revealed from the study that about 11% of the buildings fall under high risk group, 20% of the buildings fall under moderate risk group and 70% of the buildings in low risk group.
This paper presents liquefaction potential evaluation at six land development projects in Dhaka c... more This paper presents liquefaction potential evaluation at six land development projects in Dhaka city. Bangladesh has been identified as a moderate vulnerable country according to world seismic map. The country sufferred five large earthquakes having a magnitude greater than 7.0 within and just outside the country from 1865 to 1930. Recent numerous small earthquakes within the country point to the high probability of occuring a large earthquake. Most of the private land development projects of Dhaka city rested mainly on sand deposits. The ground water table is also shallow for these locations. The sites are susceptible to liquefaction during ground-shaking. Infrastructures constructed on land fill has the potential to suffer from liquefaction. To identify liquefaction potential of such areas, in situ Cone Penetration Test (CPT) has been conducted for six locations of different land development projects. The liquefaction analysis based upon force equilibrium concept cannot be directl...
Meghna Dhonagoda Irrigation Project (MDIP) is located at northern part of Chandpur district and 4... more Meghna Dhonagoda Irrigation Project (MDIP) is located at northern part of Chandpur district and 40 km south east of Dhaka near the confluence of the Padma and the Meghna River. MDIP is a 60 km long embankment. Recently, severe seepage and boiling were observed in the countryside of MDIP. To find the reason behind these problems, various laboratory and field tests at different locations of the embankment were carried out. After collected geotechnical data, cement stabilization at 11 points were suggested as remedial measures. To assess the strengthening work of MDIP at different points, geophysical investigation was carried out using Ground Penetrating Radar (GPR). A 100 megahertz (MHz) frequency antenna has been used to determine the layer profile of the embankment. Common Depth Point (CDP) and bi-static high range reflection profiling has been used for data collection.
: Unreinforced lime mortar masonry is common and oldest building pattern in older part of Dhaka c... more : Unreinforced lime mortar masonry is common and oldest building pattern in older part of Dhaka city. This type of old masonry structures consists approximately 15 percent of total building stock of 400,000 units in the city. Most of the buildings were built during Mughal period and British rule, having unique architectural style constructed by brick masonry with lime mortar. Over the years many unplanned modifications took place which is a serious threat for the houses. To identify seismic vulnerability of these buildings, structural analysis has been carried out. The details of the building including the dimension of structural elements, structural irregularities, position of openings, observed physical condition have been considered during the investigation. Direct shear test for mortar joint, compressive strength test of brick and ambient vibration measurement by microtremor have been performed. This paper represents overall techniques applied for 45 old structures in order to a...
Capacity spectrum method provides the capacity of a structure with respect to demand of a structu... more Capacity spectrum method provides the capacity of a structure with respect to demand of a structure during an earthquake. A simplified approach was used to estimate seismic demand calculation based on inelastic strength and displacement spectra. Static Pushover Analysis was performed by OpenSees program to obtain capacity curve. Response of the structure was transformed into equivalent Single Degree of Freedom (SDOF) System. Response Spectra from proposed Bangladesh National Building Code (BNBC) were transformed into acceleration displacement format. Performance point was obtained from the intersection point between bi-linear pushover curve and acceleration demand spectra.
Journal of Pipeline Systems Engineering and Practice, 2020
AbstractBuried water pipelines are subjected to corrosion deterioration and are vulnerable to ext... more AbstractBuried water pipelines are subjected to corrosion deterioration and are vulnerable to extreme events (e.g., earthquakes). Corroded metallic buried pipelines have experienced severe damage d...
ASCE Journal of Pipeline Systems - Engineering and Practice, 2019
Buried water pipelines are subjected to corrosion deterioration and are vulnerable to extreme eve... more 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). The results of the two case studies show that the restoration process has a significant influence on the shape of the FFS. Time to repair a break, number of breaks, network topology, the level of corrosion, and the available resources of utility companies are key parameters that determine the shape of the FFS. It is also observed that larger and older WDS networks experience a significantly higher number of breaks, which compromises their resilience. The proposed framework provides a useful planning tool for asset management of WDSs subjected to seismic hazards.
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Papers by Ram Krishna Mazumder