Engineering Commons^™

Behavior Of Piled Raft Foundation In Partially Saturated Soils, Salman Alrubaye

Civil & Environmental Engineering Theses & Dissertations

Current foundation design practice considers conventional pile group foundation when simpler and rather economical raft foundations do not meet one of the design criteria. However, design requirements could be met by incorporating a reduced number of piles with the raft. Piled Raft foundation (PRF) is a composite foundation in which, the piles and the raft contribute to the total resistance of the foundation.

The objective of this dissertation is to study the behavior of PRF in fully and partially saturated soils. The primary purpose of this study is to develop models capable of estimating the resistance of different types of …

Modeling Effects Of Rainwater Harvesting Systems On Water Yield Increase And Non-Beneficial Evaporation Reduction To Sustain Agriculture In A Water-Scarce Region Of China, Tennille Wade

Civil & Environmental Engineering Theses & Dissertations

The northwestern region of China, which has an arid/semiarid climate, relies heavily on agriculture to provide food for the growing population. Climate change is affecting water availability in the region, causing long periods of drought and water scarcity followed by shorter periods of heavy rainfall and excess water availability. The ridge and furrow rainwater harvesting systems (RFRWHS) are a means of solving the problem of water scarcity; the systems can replenish soil moisture, reduce non-beneficial evaporation from bare soils, and increase surface water yield. In such a region, the hydrologic cycle is dominated by soil evaporation, leading to minimal surface …

Flexural Behavior And Strength Of Doubly-Reinforced Concrete Beams With Hollow Plastic Spheres, Rutvik R. Patel

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of an investigation into the experimental and theoretical flexural behavior and strength of doubly-reinforced concrete beams with and without hollow plastic spheres. Tests are conducted on two types of beams having simply supported end conditions. To obtain experimental results, a gradually increasing two-point loading is used up to collapse. The experimental load-deflection and load-strain curves are recorded. Theoretical analysis is based on developing non-linear moment-curvature relationships for cross sections with and without hollow spheres. These moment-curvature relationships are then coupled with three separate numerical methods namely, finite difference method, finite integral method and Newmark’s method …

Techno-Economic And Life Cycle Assessment Of Hydrothermal Processing Of Microalgae For Biofuels And Co-Product Generation, Andrew P. Bessette

Civil & Environmental Engineering Theses & Dissertations

Traditional processing methods of algae to biofuels require dewatering after harvesting of the algae before the lipids can be extracted. This is typically the most energy intensive and therefore the most expensive step. Old Dominion University (ODU) has successfully utilized a flash hydrolysis (a kind of hydrothermal) process where proteins are solubilized into the liquid phase of product and the remainder lipid-rich, low nitrogen product is separated into a solid phase. The solid phase (lipid-rich) is then an ideal candidate for biofuel feedstock and the liquid phase, or hydrolysate, can be used for coproducts such as a source of nutrients …

Simplified, Alternative Formulation Of Numerical Simulation Of Proton Exchange Membrane Fuel Cell, Russell L. Edwards

Mechanical & Aerospace Engineering Theses & Dissertations

Three-Dimensional proton exchange fuel cell (PEMFC) operation in steady-state is simulated with computational fluid dynamics / multiphysics software that is based upon the finite-element method. PEMFC operation involves the simultaneous simulation of multiple, interconnected physics involving fluid flows, heat transport, electrochemical reactions, and both protonic and electronic conduction. Modeling efforts have varied by how they treat the physics occurring within and adjacent to the membrane-electrode assembly (MEA). Several approaches treat the MEA as part of the computational domain, solving multiple, and coupled conservation equations via the CFD approach within the 3 regions of the MEA. The thickness dimensions of the …

The Evaluation Of Enhancing Biological Phosphorus Removal And Improving Settleability Using Mainstream Hydrocyclones For External Selection, Amanda Carrie Ford

Civil & Environmental Engineering Theses & Dissertations

Hydrocyclones, which receive mixed liquor tangentially, separate lighter solids from more dense solids through their tapered shape. Increasing the velocity of liquid as it moves downward allows for the selection of a desired solids fraction. Limited research has been conducted utilizing 20 m³hr^-1 hydrocyclones, with the intent of improving settleability and biological phosphorus removal (Bio-P) for mainstream processes. Improved settleability would allow for increased capacity in the secondary clarifiers which prevents the loss of biomass and subsequent treatment disruption, especially during wet weather scenarios. In addition, treatment intensification can be accomplished by maintaining a higher mixed liquor …

Predicting Effects Of Climate Change And Sea Level Rise On Hydrologic Processes In A Mid-Atlantic Coastal Watershed, Rui Li

Civil & Environmental Engineering Theses & Dissertations

This dissertation assessed impacts of Climate Change (CC) and Sea Level Rise (SLR) on coastal hydrologic processes using the Lynnhaven River watershed as a test bed. The watershed is part of Chesapeake Bay Watershed and hydraulically connected with mid-Atlantic Ocean. Six CC scenarios were considered in terms of eight Regional Climate Models’ predictions for three Intergovernmental Panel on Climate Change (IPCC) emission assumptions, namely, B1, A1B, and A2, for two future periods, namely 2046 to 2065 and 2081 to 2099. The ensemble means of downscaling results from four methods were used to represent the future climates. On the other hand, …

Celebrating 20 Years Of The Exceed Teaching Workshop, Allen C. Estes, Stephen J. Ressler P.E., Camilla M. Saviz P.E., Brock E. Barry, Carol L. Considine, Dion Coward, Norman D. Dennis Jr., P.E., Scott R. Hamilton P.E., David S. Hurwitz, Tanya Kunberger P.E., Thomas A. Lenox, Tonya Lynn Nilsson, Leslie Nolen Cae, James J. O'Brien Jr., Robert James O'Neill, David A. Saftner, Kelly Salyards P.E., Ronald W. Welch P. E.

Engineering Technology Faculty Publications

In response to the clear need for faculty training, the American Society of Civil Engineers (ASCE) developed and funded Project ExCEEd (Excellence in Civil Engineering Education) which is celebrating its twentieth year of existence. For the past two decades, 38 ExCEEd Teaching Workshops (ETW) have been held at six different universities. The program has 910 graduates from over 267 different U.S. and international colleges and universities. The ExCEEd effort has transformed from one that relied on the grass roots support of its participants to one that is supported and embraced by department heads and deans. This paper summarizes the history …

Manufacturing Applications Of The One-Dimensional Cutting Stock Problem As A Team Project, Hüseyin Sarper, Nebojsa I. Jaksic

Electrical & Computer Engineering Faculty Publications

This paper explains the beneficial and practical impact of operations research in two real manufacturing settings. Two manufacturing examples used in student projects were (1) cutting rails (80‘ or 40‘) to manufacture railroad frogs of many sizes and (2) cutting round metal rolls (12‘ to 20‘) to meet customer demands for various lengths of cuts. Student teams in Engineering of Manufacturing Processes and Operations Research courses wrote computer programs. The program first identified all possible patterns that can be cut out of a given stock length. Next, the program created a mathematical model (a text file) as an output. This …

Collaborative Strategies For Sea Level Rise Adaptation In Hampton Roads, Virginia, Carol Considine, Emily Steinhilber

Engineering Technology Faculty Publications

[Introduction] The Hampton Roads region is located in southeastern Virginia where the Chesapeake Bay meets the Atlantic Ocean. The region includes seventeen municipal governments and has a large federal government presence with 26 federal agencies represented (See Figure 1). The region has a population that exceeds 1.7 million and is home to the deepest water harbor on the U.S. East Coast. Hampton Roads' economy is dependent on the local waterways and houses the world's largest naval facility, the sixth largest containerized cargo complex and supports a thriving shipbuilding and repair industry as well as a tourism industry. However, the region's …

Transforming Yekaterinburg Into A Safe, Resilient-Smart And Sustainable City, S. A. Timashev, V. N. Alekhin, L. V. Poluyan, I. Fontanals, A. Gheorghe

Engineering Management & Systems Engineering Faculty Publications

The initiative (since 2014) project described in this paper is a product of a joint innovative research and implementation effort of the Civil Engineering and Architecture Institute, Ural Federal University, the Science and Engineering Centre "Reliability and Safety of Large Systems and Machines", Ural Branch Russian Academy of Sciences (both Yekaterinburg), Start-up OptiCits, Barcelona, Spain and the Old Dominion University, Norfolk, VA, USA. The project is based on using the MAICS convergent technology [1] to create a versatile multi-purpose tool for optimizing the science and art of risk based governance of resilience-smart and sustainable city infrastructure and communities operating in …

Hurricane Evacuation Modeling Using Behavior Models And Scenario-Driven Agent-Based Simulations, Yuan Zhu, Kun Xie, Kaan Ozbay, Hong Yang

Computational Modeling & Simulation Engineering Faculty Publications

Transportation modeling and simulation play an important role in the planning and management of emergency evacuation. It is often indispensable for the preparedness and timely response to extreme events occurring in highly populated areas. Reliable and robust agent-based evacuation models are of great importance to support evacuation decision making. Nevertheless, these models rely on numerous hypothetical causal relationships between the evacuation behavior and a variety of factors including socio-economic characteristics and storm intensity. Understanding the impacts of these factors on evacuation behaviors (e.g., destination and route choices) is crucial in preparing optimal evacuation plans. This paper aims to contribute to …

Value Added Products From Lignin And Biomass Derivatives, Chen Li

Civil & Environmental Engineering Theses & Dissertations

Pyrolysis is one of the traditional lignin and biomass utilization methods. The liquid products bio-oil and solid products bio-char are the main value-added products from lignin pyrolysis. Due to the narrow application and low quality, using the pyrolysis method to produce bio-oil and bio-char cannot bring sufficient economic benefits. In this dissertation, two methods were investigated to improve the quality of lignin bio-products.

Instead of direct pyrolysis, chemical activation (pyrolysis) was introduced in this dissertation. Compared to bio-char, the lignin chemical activation product lignin-activated-carbon has better economic value. With the best activation conditions, the lignin-activated-carbon produced a surface area of …

Combined Effect Of Storm Surge And Overland Flow On Flooding In A Coastal Urban Area, Navid Tahvildari, Akash Sahu, Yawen Shen, Mohamed Morsy, Jonathan Goodall

Civil & Environmental Engineering Faculty Publications

The coastal regions in the U.S. East Coast and the Gulf of Mexico are under the risk of storm surge and precipitation-driven flooding. The adverse impacts of climate change including sea level rise (SLR), potential increase in intensity and frequency of extreme storms, and increase in precipitation intensity increases the vulnerability of coastal communities to flooding. The common practice for flood hazard assessment in urban coastal areas can result in some errors as the effect of storm surge and overland flow are not considered simultaneously. In this study, we combine the results of two hydrodynamic models, one for overland flow …

Investigation Of Ribbed Dome Including Tuned Mass Damper, Ali Parva

Civil & Environmental Engineering Master's Projects

This research report presents the outcome of an investigation of lightweight ribbed steel dome structure. The proposed ribbed dome structure is studied both numerically and experimentally under static, natural vibration, and base excitation conditions. The base excitation is considered in the form of a sinusoidal as well as seismic loading in the form of a scaled-down 1940 El Centro earthquake. A numerical study of the ribbed dome is also conducted including a tuned mass damper (TMD). The performance of the dome is also compared with that of a hexagonal vertical structure showing a superior response of the dome under seismic …

Modeling The Impacts Of Sea Level Rise On Storm Surge Inundation In Flood-Prone Urban Areas Of Hampton Roads, Virginia, Luca Castrucci, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Hampton Roads is a populated area in the United States Mid-Atlantic region that is highly affected by sea level rise (SLR). The transportation infrastructure in the region is increasingly disrupted by storm surge and even minor flooding events. The purpose of this study is to improve our understanding of SLR impacts on storm surge flooding in the region. We develop a hydrodynamic model to study the vulnerability of several critical flood-prone neighborhoods to storm surge flooding under several SLR projections. The hydrodynamic model is validated for tide prediction, and its performance in storm surge simulation is validated with the water …

Optimizing Nature-Based Features For Wave Dissipation And Land-Water Connectivity, Maura Boswell, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

Living shorelines integrate structural and natural features to stabilize the shoreline, through reduction of erosion from the wave climate, while keeping the connectivity between land and aquatic ecosystems. This study includes field study for two different types of living shoreline systems to quantify and compare their wave dissipation services and provide physics-based guidance for the design of living shoreline systems that are efficient in wave dissipation yet maximize land-water connectivity.

A Numerical Study On Surface Wave Evolution Over Viscoelastic Mud, Elham Sharifineyestani, Navid Tahvildari

Civil & Environmental Engineering Faculty Publications

A numerical modeling approach is applied to investigate the combined effect of wave-current-mud on the evolution of nonlinear waves. A frequency-domain phase-resolving wave-current model that solves nonlinear wave-wave interactions is used to solve wave evolution. A comparison between the results of numerical wave model and the laboratory experiments confirms the accuracy of the numerical model. The model is then applied to consider the effect of mud properties on nonlinear surface wave evolution. It is shown that resonance effect in viscoelastic mud creates a complex frequency-dependent dissipation pattern. In fact, due to the resonance effect, higher surface wave frequencies can experience …