Engineering Commons^™

Design Of Bamboo Reinforced Concrete Beams Considering Variability In Tensile Strength Of Bamboo, Bibek Bhardwaj, Michael Stoner, Weichiang Pang

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In recent years, the price of steel has soared, making steel reinforcement in concrete structures unaffordable for households in low-income countries. Seismic activities in low-income households, particularly those in developing countries, pose a significant threat to life and property to unreinforced concrete structures. The application of bamboo as an alternative to steel in reinforced concrete is still in its early stages of development. Unlike steel, bamboo is a natural material, and its structural properties vary greatly based on species, location, age, and geometric properties. Thus, the design of bamboo-reinforced concrete involves more uncertainties than steel-reinforced concrete. This research investigates the …

Adaptive Signal System Safety Impacts Final Report, Mashrur Chowdhury, Weiman Jin, M. Sabbir Salek, Sakib Mahmud Khan, Katherine Brunk, Patrick Gerard, Nathan Huynh, Mohammad Torkjazi

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The research team conducted a literature review and a nation-wide survey at the beginning of the research. The literature review revealed that Adaptive Signal Control System (ASCS) was effective in reducing crashes in some studies, while in other studies, the crash reduction due to ASCS was not statistically significant. Twenty-eight states participated in the nation-wide survey and helped the research team identify corridor characteristics, such as the design speed and Annual Average Daily Traffic (AADT) of an ASCS corridor, which would allow for the best operational and safety outcomes. Then, to determine the safety effects of ASCS, the research team …

Investigating The Impacts Of Crash Prediction Models On Quantifying Safety Effectiveness Of Adaptive Signal Control Systems, Weimin Jin, Mashrur Chowdhury, Sakib Mahmud Khan, Patrick Gerard

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Introduction: Adaptive Signal Control System (ASCS) can improve both operational and safety benefits at signalized corridors. Methods: This paper develops a series of models accounting for model forms and possible predictors and implements these models in Empirical Bayes (EB) and Fully Bayesian (FB) frameworks for ASCS safety evaluation studies. Different models are validated in terms of the ability to reduce the potential bias and variance of prediction and improve the safety effectiveness estimation accuracy using real-world crash data from non-ASCS sites. This paper then develops the safety effectiveness of ASCS at six different corridors with a total of 65 signalized …

A Probabilistic Casualty Model To Include Injury Severity Levels In Seismic Risk Assessment, Weichiang Pang, S. Majdalaweyh, A. Safiey, K. Rokneddin, S. Prabhu, M. Javanbarg, E. Ziaei

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Despite the increasing adoption of Performance-Based Earthquake Engineering (PBEE) in seismic risk assessment and design of buildings, earthquakes resulted in around 1.8 million injuries (three times the number of fatalities) over the past two decades. Several existing PBEE-based methodologies use rudimentary models that may not accurately estimate earthquake-induced casualties. Even when models are suitable for predicting the total number of fatalities and critical injuries, they may fail to adequately differentiate between different levels of injury severity. This paper draws attention to the importance of extending the seismic casualty assessment method by broadening the perspective on injury severity. To this cause, …

Investigating Hierarchical Effects Of Adaptive Signal Control System On Crash Severity Using Random-Parameter Ordered Regression Models Incorporating Observed Heterogeneity, Weimin Jin, Mashrur Chowdhury, M. Sabbir Salek, Sakib Mahmud Khan, Patrick Gerard

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No abstract provided.

Ground Motion Duration Effects On The Seismic Risk Assessment Of Wood Light-Frame Buildings, Weichiang Pang, A. Safiey, S. Majdalaweyh, E. Ziaei, K. Rokneddin, M. Javanbarg

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Wood construction comprises a large portion of building stocks of several countries across the globe with high preparedness for earthquakes including Japan, Canada, and the United States. Built environments of these countries are prone to long-duration ground shakings due largely to the proximity of subduction faulting systems. However, the current seismic design requirements do not adequately emphasize this key feature of ground motions. This study evaluates the impact of long-duration ground motions on seismic risk characteristics of code-conforming wood lightframe buildings. To this end, a study matrix of wood light-frame buildings is developed incorporating with two different heights (i.e., 1-story …

The Influence Of Incorporation Of Mn On The Pitting Corrosion Performance Of Crfeconi High Entropy Alloy At Different Temperatures, H. Torbati-Sarraf, Mitra Shabani, Paul D. Jablonski, Garrett J. Pataky, A. Poursaee

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The electrochemical behavior and susceptibility to pitting corrosion of CrFeCoNi and CrMnFeCoNi high entropy alloys were studied in a 0.1 M NaCl solution at temperatures ranging from 25 to 75 °C. Electrochemical measurements revealed that CrMnFeCoNi is more susceptible to oxide film breakdown and localized corrosion compared to CrFeCoNi. Post corrosion microscopic observations showed severe pitting corrosion for CrMnFeCoNi in higher temperatures compared to CrFeCoNi. Based on in-depth XPS profile measurements on the remaining oxide films, this behavior was attributed to the depletion of Cr in the oxide film and detrimental presence of Mn in the matrix solid solution of …

Dynamic Identification Of Soil-Structure System Designed By Direct Displacement-Based Method For Different Site Conditions, Vahidreza Mahmoudabadi, Omid Bahar, Mohammad Kazem Jafari, Amir Safiey

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This study mainly aims to assess the performance of soil-structure systems designed by direct displacement-based method coupled with strong column-weak beam design concept through various system identification techniques under strong ground motions. To this end, various system identification methods are employed to evaluate the dynamic characteristics of a structure (i.e., modal frequency, system damping, mode shapes, and plastic hinge formation pattern) under a strong seismic excitation considering soil-structure interaction for different site conditions as specified by ASCE 7-10. The scope of the study narrowed down to the code-complying low- to high-rise steel moment resisting frames with various heights (4, 8, …

Seismic Vulnerability Assessment Of Anchored Block Type Contents Due To Sliding And Overturning, Sereen Majdalaweyh, Weichiang Pang, Amir Safiey, Ershad Ziaei, Keivan Rokneddin, Mohammad Javanbarg, Saurabh Prabhu

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Damage to contents and nonstructural components is often the main driver of property losses against smaller earthquakes as evidenced by empirical evidence from past events. In the 2014 South Napa earthquake in California, for example, 56% of the affected buildings reported content damage. The primary modes of content damage include sliding, rocking, and overturning. The FEMA P-58 document provides seismic fragility functions for sliding and overturning of unanchored block content types, but no data is provided for anchored components. The ASCE/SEI 7-16 provides stability guidelines for different types of nonstructural components, but falls short of providing recommendations for the contents …

Seismic Performance Of Mid-Rise Code-Conforming X-Braced Steel Frames, Mokhtar Ansari, Hosein Gholi Pour, Amir Safiey

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Prolixity and complexities inherent in the nonlinear dynamic analysis (NDA) impel engineers to lean towards nonlinear static analysis (NSA) in practice. This paper partly explores differences and similarities in responses obtained from these two simulation techniques. The scope of the study is narrowed down to ubiquitous regular code-conforming mid-rise steel X-braced frames. Different common lateral load patterns are coupled with NSA to study their interactive effects on responses. The modal nonlinear static analysis is also carried out, where deemed necessary. NDA using three different earthquake records are conducted as well, to validate NSA results. Results of nonlinear analyses are undertaken …

Development And Evaluation Of Recurrent Neural Network-Based Models For Hourly Traffic Volume And Annual Average Daily Traffic Prediction, Zadid Khan, Sakib Mahmud Khan, Kakan Dey, Mashrur Chowdhury

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The prediction of high-resolution hourly traffic volumes of a given roadway is essential for transportation planning. Traditionally, automatic traffic recorders (ATR) are used to collect these hourly volume data. These large datasets are time-series data characterized by long-term temporal dependencies and missing values. Regarding the temporal dependencies, all roadways are characterized by seasonal variations that can be weekly, monthly or yearly, depending on the cause of the variation. Traditional time-series forecasting models perform poorly when they encounter missing data in the dataset. To address this limitation, robust, recurrent neural network (RNN)-based, multi-step-ahead forecasting models are developed for time-series in this …

A State-Of-The-Art Review Of Bending And Shear Behaviors Of Corrosion-Damaged Reinforced Concrete Beams, Mahmoodreza Soltani, Amir Safiey, Almarie Brennan

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Steel corrosion is mainly at fault for the trend of deterioration among U.S. infrastructure—namely, bridges, pipelines, and wharves. Reinforced concrete (RC) is used as the primary construction material worldwide. Reinforcement corrosion can significantly impair mechanical properties of RC members, including shear and bending capacities. In the past decades, several attempts have been made to investigate the impacts of corrosion on the mechanical behavior of RC members. It can be observed that the number of research programs conducted on this topic has rapidly increased in recent years. Therefore, there is a need in the body of knowledge to encapsulate the relevant …

Situation-Aware Left-Turning Connected And Automated Vehicle Operation At Signalized Intersections, Sakib Mahmud Khan, Mashrur Chowdhury

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One challenging aspect of the Connected and Automated Vehicle (CAV) operation in mixed traffic is the development of a situation-awareness module for CAVs. While operating on public roads, CAVs need to assess their surroundings, especially the intentions of non-CAVs. Generally, CAVs demonstrate a defensive driving behavior, and CAVs expect other non-autonomous entities on the road will follow the traffic rules or common driving behavior. However, the presence of aggressive human drivers in the surrounding environment, who may not follow traffic rules and behave abruptly, can lead to serious safety consequences. In this paper, we have addressed the CAV and non-CAV …

Fiber Element-Based Nonlinear Analysis Of Concrete Bridge Piers With Consideration Of Permanent Displacement, Mokhtar Ansari, Farhad Daneshjoo, Amir Safiey, Naser Safaeian Hamzehkolaei, Maryam Sorkhou

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Utilization of fiber beam-column element has gained considerable attention in recent years due mainly to its ability to model distributed plasticity over the length of the element through a number of integration points. However, the relatively high sensitivity of the method to modeling parameters as well as material behavior models can pose a significant challenge. Residual drift is one of the seismic demands which is highly sensitive to modeling parameters and material behavior models. Permanent deformations play a prominent role in the post-earthquake evaluation of serviceability of bridges affected by a near- fault ground shaking. In this research, the influence …

Development Of Statewide Annual Average Daily Traffic Estimation Model From Short-Term Counts: A Comparative Study For South Carolina, Sakib Mahmud Khan, Sababa Islam, Md Zadid Khan, Mashrur Chowdhury, Nathan Huynh, Mohammad Torkjazi

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Annual Average Daily Traffic (AADT) is an important parameter for traffic engineering analysis. Departments of Transportation continually collect traffic count using both permanent count stations (i.e., Automatic Traffic Recorders or ATRs) and temporary short-term count stations. In South Carolina, 87% of the ATRs are located on interstates and arterial highways. For most secondary highways (i.e., collectors and local roads), AADT is estimated based on short-term counts. This paper develops AADT estimation models for different roadway functional classes with two machine learning techniques: Support Vector Regression (SVR) and Artificial Neural Network (ANN). The models predict AADT from short-term counts. The results …

Evaluation Of Seismic Performance Of Mid-Rise Reinforced Concrete Frames Subjected To Far-Field And Near-Field Ground Motions, Mokhtar Ansari, Masoud Ansari, Amir Safiey

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Damages to buildings affected by a near-fault strong ground motion are largely attributed to the vertical component of the earthquake resulting in column failures, which could lead to disproportionate building catastrophic collapse in a progressive fashion. Recently, considerable interests are awakening to study effects of earthquake vertical components on structural responses. In this study, detailed modeling and time-history analyses of a 12-story code-conforming reinforced concrete moment frame building carrying the gravity loads, and exposed to once only the horizontal component of, and second time simultaneously the horizontal and vertical components of an ensemble of far-field and near-field earthquakes are conducted. …

Influence Of Irreparability Fragility On Seismic Vulnerability Assessment Of Buildings, Amir Safiey, Ershad Ziaei, Mengzhe Gu, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg

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The probability that a building is sanctioned to demolition following an earthquake depends on several geotechnical, structural, strategic and financial decision variables. This paper explores the literature on post-earthquake reparability assessment of buildings focusing on structural characteristics and evaluates their approaches for four midrise code-compliant structural systems, namely, steel moment frame, reinforced concrete moment frame, light frame wood, and steel braced frame. The structural responses are estimated using incremental dynamics analysis (IDA) in accordance with FEMA P-695 provisions and the IDA results are relayed to a building-specific loss assessment framework to estimate their seismic vulnerability in terms of monetary losses. …

Seismic Vulnerability Assessment Of Buildings Using A Statistical Method Of Response Prediction, Ershad Ziaei, Amir Safiey, Weichiang Pang, Keivan Rokneddin, Mohammad Javanbarg, Mengzhe Gu

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The seismic vulnerability functions for portfolio-level loss estimation are typically developed for general classes of buildings which may not be suitable to assess building-specific risks. Performance-based earthquake engineering (PBEE) provides the means to conduct building-specific seismic risk assessments. However, such assessments often rely on computationally-intensive analytical frameworks such as incremental dynamics analysis (IDA) which poses a challenge for many types of risk assessment projects. To expand its accessibility, FEMA P-58 outlines a simplified method to predict the nonlinear responses of buildings in which the scope is limited to lower levels of inter-story drifts (less than 4%). This limitation restricts its …

Simulation Of The Behavior Of Corrosion Damaged Reinforced Concrete Beams With/Without Cfrp Retrofit, Masoud Zabihi-Samani, Mohsenali Shayanfar, Amir Safiey, Amir Najari

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Harsh environmental conditions along with aggressive chemical agents are known as one of the main reasons behind damages observed in reinforced concrete members. Corrosion of reinforcement worldwide is one of the leading causes of damages occurred in reinforced concrete over the lifespan. There are many critical energy and transportation infrastructures located on coastal regions exposed to high humidity and chloride content where they are highly prone to reinforcement corrosion. This calls for retrofit methods, which safeguard not only the strength but also the durability of corrosion deteriorated reinforced concrete structures. Carbon fiber polymers considering their mechanical and chemical properties are …

Increase In The Reduction Potential Of Uranyl Upon Interaction With Graphene Oxide Surfaces, V. N. Bliznyuk, N. Conroy, Y. Xie, R. Podila, A. Rao, Brian A. Powell

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Coordination of uranyl (U(VI)) with carboxylate groups on functionalized graphene oxide (GO) surfaces has been shown to alter the reduction potential of the sorbed uranium ion. A quantitative measure of the reduction potential and qualitative estimation of sorption/desorption processes were conducted using cyclic voltammetry, and the proposed coordination environment was determined using the surface sensitive attenuated total reflection mode of infrared spectroscopy (ATR-FTIR). GO is a nanostructured material possessing a large amount of oxygen-containing functional groups both on basal planes and at the edges, which can form strong surface complexes with radionuclides. The presence of these functional groups on the …

A Comparative Study On The Durability Of Geopolymer Mortars Produced With Ground Glass Fiber, Fly Ash, And Glass-Powder In Sodium Sulfate Solution, Hassan Rashidian-Dezfouli, Prasada Rao Rangaraju

Publications

An experimental investigation was conducted to investigate the performance of geopolymers made with three different precursors consisting of fly ash, Ground Glass Fiber (GGF), and Glass-Powder (GLP) exposed to sodium sulfate solution. Precursors were activated using either sodium hydroxide solution or combinations of sodium hydroxide and sodium silicate solution with varying levels of sodium and silica content. Among the mixtures with each of the three precursors, mortar mixtures with the highest compressive strength were selected to test their resistance against exposure to a 5% sodium sulfate solution. Changes in the weight and compressive strength of the specimens were monitored up …

Real-Time Traffic State Estimation With Connected Vehicles, Sakib Mahmud Khan, Kaken Dey, Mashrur Chowdhury

Publications

A novel framework is developed in this paper, to increase the real-time roadway traffic condition assessment accuracy, which integrates connected vehicle technology (CVT) with artificial intelligence (AI) paradigm forming a CVT-AI method. Traffic density is a major indicator of traffic conditions. In this paper, the traffic operational condition is assessed based on traffic density. A simulated network of Interstate 26 in South Carolina is developed to investigate the effectiveness of the method. The assumption is that the vehicle onboard units will forward the CV generated data to the edge devices (e.g., roadside units) for further processing. CV generated distance headway …

The Soil Moisture Velocity Equation, Fred L. Ogden, Myron B. Allen, Wencong Lai, Jianting Zhu, Mookwon Seo, Craig C. Douglas, Cary A. Talbot

Publications

Numerical solution of the one-dimensional Richards' equation is the recommended method for coupling groundwater to the atmosphere through the vadose zone in hyperresolution Earth system models, but requires fine spatial discretization, is computationally expensive, and may not converge due to mathematical degeneracy or when sharp wetting fronts occur. We transformed the one-dimensional Richards' equation into a new equation that describes the velocity of moisture content values in an unsaturated soil under the actions of capillarity and gravity. We call this new equation the Soil Moisture Velocity Equation (SMVE). The SMVE consists of two terms: an advection-like term that accounts for …

Enhancing Anaerobic Digestion Of Food Waste Through Biochemical Methane Potential 1 Assays At Different Substrate: Inoculum Ratios, Shakira R. Hobbs, Amy E. Landis, Bruce E. Rittmann, Michelle N. Young, Prathap Parameswaran

Publications

Food waste has a high energy potential that can be converted into useful energy in the form of methane via anaerobic digestion. Biochemical Methane Potential assays (BMPs) were conducted to quantify the impacts on methane production of different ratios of food waste. Anaerobic digester sludge (ADS) was used as the inoculum, and BMPs were performed at food waste:inoculum ratios of 0.42, 1.42, and 3.0 g chemical oxygen demand/g volatile solids (VS). The 1.42 ratio had the highest CH4-COD recovery: 90% of the initial total chemical oxygen demand (TCOD) was from food waste, followed by ratios 0.42 and 3.0 at 69% …

Do Single-Use Medical Devices Containing Biopolymers Reduce The Environmental Impacts Of Surgical Procedures Compared With Their Plastic Equivalents?, Scott R. Unger, Troy A. Hottle, Shakira R. Hobbs, Cassandra L. Thiel, Nicole Campion, Melissa M. Bilec, Amy E. Landis

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Background: While petroleum-based plastics are extensively used in health care, recent developments in biopolymer manufacturing have created new opportunities for increased integration of biopolymers into medical products, devices and services. This study compared the environmental impacts of single-use disposable devices with increased biopolymer content versus typically manufactured devices in hysterectomy.

Methods: A comparative life cycle assessment of single-use disposable medical products containing plastic(s) versus the same single-use medical devices with biopolymers substituted for plastic(s) at Magee-Women’s Hospital (Magee) in Pittsburgh, PA and the products used in four types of hysterectomies that contained plastics potentially suitable for biopolymer substitution. Magee is …

Changes In Temporal Variability Of Precipitation Over Land Due To Anthropogenic Forcings, Goutam Konapala, Ashok Mishra, L. Ruby Leung

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This study investigated the anthropogenic influence on the temporal variability of annual precipitation for the period 1950–2005 as simulated by the CMIP5 models. The temporal variability of both annual precipitation amount (PRCPTOT) and intensity (SDII) was first measured using a metric of statistical dispersion called the Gini coefficient. Comparing simulations driven by both anthropogenic and natural forcing (ALL) with simulations of natural forcing only (NAT), we quantified the anthropogenic contributions to the changes in temporal variability at global, continental and sub-continental scales as a relative difference of the respective Gini coefficients of ALL and NAT. Over the period of 1950–2005, …

Analytical Content Vulnerability Assessment Methodology For Earthquake Catastrophe Models, Keivan Rokneddin, Amir Safiey, Mohammad Javanbarg, Vijay Manghnani, Weichiang Pang

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The scarcity of detailed claims data for building contents (Coverage C) from historical earthquake events poses a significant challenge for property insurance catastrophe models to reliably estimate the losses associated to building contents. To develop content vulnerability functions empirically, one would need to have access to data from a multitude of historical events; however, loss disaggregation by coverage is rarely reported even when claims data become available from recent significant events such as Maule (2010) and Tohoku (2011). While damage to the building structure (Coverage A) can be estimated analytically using simulation-based fragility functions to amend sparse historical observations, the …

Development Of Earthquake Vulnerability Functions And Risk Curves For Low And Mid-Rise Hotel Buildings Using A Performance-Based Loss Estimation Framework, Amir Safiey, Weichiang Pang, Mohammad Javanbarg, Keivan Rokneddin, Ershad Ziaei

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The concept of performance-based earthquake engineering has gained significant attentions in both the research and engineering communities. The development of a performance-based seismic loss assessment framework, known as the FEMA P-58 method, allows one to estimate the potential financial losses of a building using performance-based engineering method. This research employs a seismic loss estimation framework derived using the P-58 method to estimate the monetary loss of a mid-rise wood-frame hotel building which is assumed to be located in Napa Valley, California. A 3D structural model representative of the dynamic behavior of the wood-frame hotel was created and subjected to Incremental …

Role Of Ground Glass Fiber As A Pozzolan In Portland Cement Concrete, Hassan Rashidian-Dezfouli, Prasad Rao Rangaraju

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Millions of tons of fiberglass are produced annually for a variety of applications. Because of stringent quality requirements and operational characteristics of the manufacturing plants, a significant quantity of fiberglass that does not meet required specifications of the industry ends up as waste in landfills. This study investigated the use of ground glass fiber (GGF) that had been discarded by plants because it did not meet prescribed standards, as a supplementary cementitious material (SCM) for portland cement. Three replacement levels (10%, 20%, and 30% by mass) for portland cement in paste, mortar, and concrete mixtures were studied. Mechanical and durability …

Integration Of Structural Health Monitoring And Intelligent Transportation Systems For Bridge Condition Assessment: Current Status And Future Direction, Sakib Mahmud Khan, Sez Atamturktur, Mashrur Chowdhury, Mizanur Rahman

Publications

Recent catastrophic bridge failures clearly indicate the urgent need for improving interval-based bridge inspection procedures that are qualitative and subjective in nature. Structural Health Monitoring (SHM) can mitigate the deficiencies of interval-based inspection techniques and provide real-time diagnostic information regarding the bridge structural health. SHM is not flawless however; the variability in the vehicle characteristics and traffic operational conditions makes it prone to false diagnosis. Recent advancements in the integration of SHM with intelligent transportation systems (ITS) demonstrate the successful use of ITS devices (e.g., traffic cameras, traffic detectors) in the analysis of bridge responses to multimodal traffic with varying …