Civil Engineering Commons^™

Characterization Of Human-Induced Vibrations, Benjamin Thomas Davis

Theses and Dissertations

In the US alone, 20% of citizens will be over the age of 65 by the year 2030, and the largest challenge facing this growing demographic is not a new disease but a simple motion - the fall. These events are the premier cause of fatal and nonfatal injuries. In fact, a fall is so common that every 17 seconds an older adult is treated for fall-related injuries, and every 30 minutes, an older adult dies from fall complications. Research has shown a positive outcome of a fall event is largely dependent on the immediate response (<30 minutes) and rescue of the person.

This work explores …

Deposits Emplaced In Upper Regime, Ricardo Rafael Hernández Moreira

Theses and Dissertations

Relatively common to the submarine setting are depositional sequences that begin with a lower erosional boundary, followed in ascending order by a either a graded or an inherently massive basal unit, a relatively coarse parallel laminated unit, a cross laminated unit, a relatively fine parallel laminated unit, and a capping layer of massive mud. These sequences are present in turbidity current, coastal storm and tsunami deposits, and their study is the key to understanding the physical processes governing sediment transport, erosion and deposition in submarine settings, to the reconstruction of global paleoclimate and paleoflow, to the exploration of hydrocarbon reservoirs …

Use Of Biochar-Ultrafiltration Membrane Processes For Removal Of Humic Acid, Vaibhavi Shankar

Theses and Dissertations

The performance of an ultrafiltration (UF)-biochar process was evaluated in comparison with a UF membrane process for the removal of humic acid (HA). Bench-scale UF experiments were conducted to study the rejection and flux trends under various hydrodynamic, pH, conductivity, and pressure conditions. The resistance-in-series model was used to evaluate the processes and it showed that unlike stirred conditions, where low fouling resistance was observed, comparable trends were obtained for UF-biochar and UF alone for unstirred conditions. Thus, the processes were further evaluated under unstirred conditions. Additionally, total fouling resistance was decreased in the presence of biochar, indicating that HA …

Modeling Embankment Breach Due To Overtopping, Ali Asghari Tabrizi

Theses and Dissertations

Despite numerous embankment failures around the world, in-depth assessments as well as reliable, comprehensive sets of data of such failures are limited. Detailed understanding of the earthen embankment failure process and the dominant parameters affecting the failure are needed to predict and model the breach process precisely. Therefore, a series of laboratory experiments on embankment (i.e., dam and levee) overtopping as well as erodibility measurements using the Submerged Jet test are conducted. Also, to study the influence of different model parameters (e.g., turbulence model, bedload formula), one of the dam embankment experiments is simulated. The main goal of this research …

Addressing The Impact Of Gavins Point Dam On The Lowermost~1400 Kilometers Of The Missouri River, Gregory Leaphart

Theses and Dissertations

The Missouri River originates in the Rocky Mountains in western Montana and joins the Mississippi River near St. Louis, Missouri. Beginning in the early 1900s, engineering efforts, such as dam construction, channel narrowing, and river alignment, were performed for flood control, navigational purposes, to use of water for agricultural and industrial needs, to produce hydroelectric power and the impounded lakes for recreation. These projects permanently altered the flow and sediment transport regimes in the river and the exchange of sediment with the surrounding floodplain. We focus on the long term effects of dam construction and channel narrowing on approximately the …

Evaluation Of Concrete Degradation Using Acoustic Emission: Data Filtering And Damage Detection, Marwa A. Abdelrahman

Theses and Dissertations

The prevalence of aging and deteriorating infrastructure in the U.S. has raised concerns regarding its level of serviceability, reliability, and vulnerability to natural disasters. This issue has gained attention recently and efforts are being conducted to accelerate the delivery of enhanced nondestructive testing (NDT) and structural health monitoring (SHM) methods. Acoustic emission (AE) is a strong candidate for these applications due to its high sensitivity and potential for damage detection in different materials. However, several challenges associated with the technique hinder the development of automated, reliable, real-time SHM using AE.

This study aims to advance the use of AE for …

Improved Assessment Of The Magnitude And Acceleration Of Prehistoric Earthquakes In The South Carolina Coastal Plain, Emad Gheibi

Theses and Dissertations

Seismically-induced soil liquefaction is one the most hazardous geotechnical phenomenon that can cause loss of life and devastating damage to infrastructure. Proper estimation of critical ground motion parameters (e.g. peak ground acceleration and earthquake magnitude) is vital for seismic design of new structures and retrofit of existing structures, especially in regions such as the South Carolina Coastal Plain (SCCP) where the frequency of re-occurrence of large earthquakes is low (studies of paleoliquefaction features have revealed seven, large, prehistoric earthquakes occurring within the last 6000 years) and the locations of potential sources are not exactly known. Moreover, due to mechanical and …

Assessment Of Classifiers For Potential Voice-Enabled Transportation Apps, Md Majbah Uddin

Theses and Dissertations

Transportation apps are playing a positive role for today’s technology-driven users. They provide users with a convenient and flexible tool to access transportation data and services, as well as collect and manage data. In many of these apps, such as Google Maps, their operations rely on the effectiveness of the voice recognition system. For the existing and new apps to be truly effective, the built-in voice recognition system needs to be robust (i.e., being able to recognize words spoken in different pitch and tone). The goal of this study is to assess three post-processing classifiers (i.e., bag-of-sentences, support vector machine, …

Numerical And Experimental Investigations Of Dam And Levee Failure, Ezzat Youssef Elhassan Mohamed Elalfy

Theses and Dissertations

Both numerical and experimental investigations are conducted to study the failure of earthen dams and levees. Boussinesq equations describing one-dimensional unsteady flow including non-hydrostatic pressure distribution are solved numerically along with Exner equation for the sediment mass conservation to include the effects of the streamline curvature on the failure of non-cohesive earthen embankments. In addition, the effects of the steep bottom slope on the flow variables during the failure are studied by solving the Saint- Venant equations modified for steep bed slope along with the Exner equation to simulate non-cohesive earthen embankment failure due to overtopping. The Boussinesq equations are …

Confluence Of Density Currents Over An Erodible Bed, Hassan Ismail

Theses and Dissertations

Results from laboratory experiments on conservative density current confluence are reported. Hydraulic characteristics and morphodynamic consequences of the confluence of two continuous release density currents in a horizontal, 45 degree asymmetrical junction are examined and compared to those of terrestrial river junctions. It was observed that density current confluence is markedly different than those in river junctions primarily due to the ease of the dense fluid to convect into the ambient fluid in the junction zone. Upward convection in the junction resulted in low horizontal velocity and shear stresses on the bed of the junction zone, followed by re-plunging to …

Economic Feasibility And Increased Sustainability Of Short Span Arch Culvert, Rafsan Jani Rafi

Theses and Dissertations

Short span box culverts are widely used for stream flow passing throughout the State of Arkansas. Arkansas State Highway and Transportation Department (AHTD) has standard box culverts ranging from 4 ft to 12 ft in span to use for individual box culvert combination. This study is strictly for culverts with a total span range from 10 ft to 30 ft. To achieve more than 12 ft culvert span, AHTD uses different combinations of standard box culverts. As a result, the clear span becomes smaller and may cause higher debris accumulation near the culvert openings. The goal of this study is …

Developing Pavement Performance Prediction Models For The State Of Arkansas, Lena Baker Abu-Ennab

Theses and Dissertations

Pavement management systems (PMS) provide a methodology for synthesizing all the activities related to the pavement network. These include all the activities involved in the planning and programming, design, construction, maintenance, and rehabilitation (1). The effective implementation and utilization of PMS requires a systematic approach involving condition assessment and performance modelling. A very important part of such approach is the use of pavement performance prediction models to predict the future condition of pavements based on present condition. This study presents a methodology used to develop network level pavement performance prediction models for the pavement network in the state of Arkansas. …

Modeling Force Main Systems For Surge Analysis And Studying Dynamic Response Due To Water Hammer, Wissam Al-Taliby

Theses and Dissertations

The major impact of water hammer on force mains integrity include excessive pressure oscillation that is usually accompanied by pipe vibrations. Models for simulating force main water hammer response have been developed. All of these models were based on the method of characteristics (MOC) and most of them were not calibrated for the lack of efficient field data. Although predicting maximum pressure during the first wave cycle is sufficient in most applications, some applications require precise prediction of pressure damping. One-dimensional models usually over predict pressure oscillation beyond the first cycle since they are based on steady friction expressions. It …

Engineering Properties Of Pile Rebound Soils Based On Cone Penetration Testing, Hadeel Dekhn

Theses and Dissertations

High pile rebound (HPR) has been identified by Florida Department of Transportation (FDOT) to occur during the installation of square prestressed concrete piles at many sites in Florida. Significant pile rebound values of up to 1.5 inch/blow were measured resulting in increased blow counts. Pile refusal is a common occurrence when blow count exceeds 240 blow/ft; leading to pile redesign and economic consequences. The overall objective of this research is to identify the engineering properties of soil deposits which may cause HPR and develop improved correlations that may be used to predict HPR during the design process. Seven sites were …

Integrating Pavement Crack Detection And Analysis Using Autonomous Unmanned Aerial Vehicle Imagery, Patrick J. Grandsaert

Theses and Dissertations

Efficient, reliable data is necessary to make informed decisions on how to best manage aging road assets. This research explores a new method to automate the collection, processing, and analysis of transportation networks using Unmanned Aerial Vehicles and Computer Vision technology. While there are current methodologies to accomplish road assessment manually and semi-autonomously, this research is a proof of concept to obtain the road assessment faster and cheaper with a vision for little to no human interaction required. This research evaluates the strengths of applying UAV technology to pavement assessments and identifies where further work is needed. Furthermore, it validates …

Test And Evaluation Of Ultrasonic Additive Manufacturing (Uam) For A Large Aircraft Maintenance Shelter (Lams) Baseplate, Daniel H. Gartland

Theses and Dissertations

Additive manufacturing is an exciting new manufacturing technology that could have application to Air Force Civil Engineer (CE) operations. This research replicates a Large Area Maintenance Shelter (LAMS) baseplate design for ultrasonic additive manufacturing (UAM). Due to production problems the test section was not built as designed. Instead, a smaller block of material was submitted for evaluation. After the UAM build, ultrasonic inspection was conducted to identify anomalies in the test piece. The results of this proof of concept study indicate that UAM is not yet ready for CE expeditionary applications requiring a high degree of mechanical strength. The machine …

Modeling And Simulation Of Evacuation Plan For Hancock Stadium, Nirmal Neranjan Weerasekara

Theses and Dissertations

The goal of this study is to use Modeling and Simulation of Evacuation Plan (MSEP) to support management to execute proper evacuation plan in case of emergency at Hancock Stadium in Illinois State University. Analyses of the research literature and evacuation scenarios are used to build a simulation system that will connect a description of emergency and evacuation situation with its context. It shows how an evacuation plan actually functions. The results of the study will help safety managers to understand the current situations of evacuation according to the specific simulation scenarios. The evacuation simulation is categorized according to the …

Development Of Computer Simulation Model For Urban Region Using Xp-Swmm In Savannah, Georgia, Matthew Dale Ricks

Theses and Dissertations

The objective of this thesis was to determine if it is possible to create, calibrate, and validate a computer simulation model given a limited amount of measured data. In June 1999, significant flooding was experienced throughout the Casey Canal North drainage basin in Savannah, Georgia. Time-depth rainfall data from a single gage was recorded for this event, along with peak water surface elevations throughout the basin. The computer model chosen for this application was XP-SWMM, which was approved by the Federal Emergency Management Agency to simulate both one dimensional and two dimensional hydraulic models. XP-SWMM was chosen due to its …

Adaptivity For Meshfree Point Collocation Methods In Linear Elastic Solid Mechanics, Joshua Wayne Derrick

Theses and Dissertations

This study presents the behavior of local node adaptivity for point collocation meshfree numerical methods and its application to linear elastic solid mechanics. A bisection approach to meshfree adaptivity will be presented with numerical examples showing that convergence is achieved. A threshold value is required from the user and this value is an acceptable change in gradient for the problem. If the change in gradient between 2 nodes exceed this limit, a node is added at the mid-point between the two nodes. This process applies to all nodes in the model. Once the refinement is complete, the model is processed …

Experimental Study Of Longitudinal Sorting Of Particles Differing In Size And Density, Nabila Mahjabeen

Theses and Dissertations

Transport, deposition and erosion of sediment particles differing in size, shape and density may result in particle segregation, which in geosciences applications is generally referred to as sediment sorting. A thorough understanding of sediment sorting processes is important to describe and model a wide variety of natural processes such as the decrease in particle size and/or density in a fluvial system (downstream fining and/or lightening), the formation of economic placers, concentration of heavy minerals, chemical and metal pollutants etc. Sorting of sediment grains associated with sediment transport in the streamwise direction results in the development of longitudinal sorting patterns. Vertical …

Drilled Shaft Skin Resistance Design In The Cooper Marl, William J. Gieser

Theses and Dissertations

As drilled shafts have become a more popular foundation type in the Charleston, South Carolina area, there has been an ongoing goal of optimizing drilled shaft design while maintaining the structural integrity of the foundation. In the Charleston area, the primary bearing stratum for deep foundations is the Cooper Marl, a calcareous Oligocene formation. Research performed from 2002 to 2004 on load test data from drilled shafts constructed in the Cooper Marl and soil properties from three test sites for the Cooper River Bridge explored the relationship between the measured skin resistance and geotechnical properties. In the 15 years since …

Functionalized Graphitic Nanoreinforcement For Cement Composites, Nima Zohhadi

Theses and Dissertations

Physical and mechanical properties of graphitic nanomaterials, in particular multiwalled carbon nanotubes (MWCNTs) and graphene nano-platelets (GNPs) make them promising candidates for nanoreinforcement of cement composites. The two key challenges associated with the incorporation of MWCNTs and GNPs are to attain uniform dispersion and interfacial bonding within the composite matrix. The effects of three main-stream dispersion techniques (namely, ultrasonication, acid-etching, and surfactant-coating) on the mechanical properties and microstructure of MWCNT- and GNP-cement composites were experimentally studied. Compressive strength tests and different characterization techniques including dynamic light scattering, Raman spectroscopy, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission …

Context-Sensitive Seismic Strengthening And Repair Of Substandard Confined Masonry, Rahim Ghorbani

Theses and Dissertations

Confined masonry (CM) is a construction system consisting of load-bearing masonry panels that are confined with cast-in-place reinforced concrete tie columns and beams. Due to satisfactory seismic performance, CM has become the predominant low-rise residential construction system in several areas around the world. However, in developing regions, the use of substandard materials, details and construction practices may result in inadequate performance as highlighted in the 2010 earthquakes in Haiti and Chile. In the aftermath of an earthquake, households are often reluctant to reoccupy their dwellings due to concerns about safety of structures. If feasible, preventive (pre-hazard) strengthening or structural repair …

Scheduling Of Container Handling Equipment In Marine Container Terminals, Narges Kaveshgar

Theses and Dissertations

To improve the competitiveness of marine container terminals, it is critical to minimize the makespan of a container vessel. The makespan is defined as the latest completion time among all handling tasks of the container vessel. Lower makespan (i.e. lower vessel turn time) can be achieved through better scheduling of the container handling equipment during vessel operations. The scheduling of terminal equipment is an operational problem, and a detailed schedule for each type of equipment operating in the terminal is necessary. Several studies have applied operations research techniques to optimize the processes of equipment in a terminal. This dissertation investigates …

An Engineering Approach For The Design Of Archaeological Reburial Systems, Angel Ari Perez Mejia

Theses and Dissertations

Archaeological sites are a non-renewable resource which is often our only link to the past. However, sites are under constant threat of destruction due to construction activities. Civil engineers and archaeologists must the work together to ensure both the continued survival of archaeological sites while allowing for development to continue. Reburial systems, when properly designed and constructed, allow for the protection of archaeological sites while allowing the continued use of the land. However, because reburial as an intentional conservation technique is relatively modern, practice is fragmented and there are no universally accepted guidelines. Current reburial system design relies on prescriptive …

A Cost/Benefit Evaluation Of Incentives Paid For Asphalt Concrete Hot Mix (Achm) Properties, Christopher T. Mckenney

Theses and Dissertations

The purpose of this study was establishing if projects receiving incentive payments for Asphalt Concrete Hot Mix (ACHM) properties were providing a better quality and longer pavement life cycle. Reviewing governmental agencies' and states' Department of Transportation (DOT) standards, through literary review, indicated other possible guidelines and recommendations. Results were formulated by employing a specific methodology, allowing for data validation through an ordered series of groupings and project pairings. Arkansas Highway and Transportation Department (AHTD) databases furnished essential pavement data to accomplish this task. Derived from methodology, data analysis supported the comparison analysis of selected construction projects. Documented conclusions validated …

An Analysis Of Factors That Influence The Success Of Expeditionary Civil Engineer Hub-And-Spoke Organizations, Joshua A . Hager

Theses and Dissertations

Expeditionary Air Force Civil Engineer support to recent operations in southwest Asia created a unique organizational learning environment, particularly related supporting the general engineering requirements of geographically separated units in a manpower-constrained contingency environment. One of the direct results of this organizational learning was the hub-and-spoke expeditionary engineer unit featuring elements of both RED HORSE and Prime BEEF capabilities operating with theater-wide visibility of infrastructure requirements. This study acquired insights from literature and a purposeful sample of subject matter experts about operational advantages this hub-and-spoke unit offered compared to those offered by strictly legacy organizational models. The research used a …

Case Study Analysis Of Trust And Commitment Between The Civil Engineering Commodity Council And The Civil Engineering Career Field, Jonnathan B. Page

Theses and Dissertations

The Air Force is pursuing strategic sourcing as a strategy for reducing costs of goods and services to help meet budget reductions while still performing its mission. These commodities are sourced through a number of commodity councils, each of which whom interact with their stakeholders throughout the sourcing process for that specific commodity. This research identifies factors that influence the success or failure of the sourcing process from the perspective of the Civil Engineering Commodity Council (CECC) and attempts to organize these factors within a framework built around trust and its effect on commitment and cooperation. These factors were identified …

An Analysis Of Turnover Intentions: A Reexamination Of Air Force Civil Engineering Company Grade Officers, Joshua D. Connell

Theses and Dissertations

A potential retention problem is facing company grade officers (CGOs) in the Air Force Civil Engineer (CE) career field. This is due to the stress caused by a demanding workload experienced during a prolonged period of conflict (Iraq and Afghanistan), which is compounded by a reduction in force. The possibility of reduced retention is thus a concern for CE leadership. Based on past research, and the prior study conducted by Riddel (2010), a new model of turnover intentions was developed. The new model expands on Riddel's simplified model of turnover and attempts to focus on key factors that may help …

Turnover Intentions: A Quantitative Analysis Of Comments From Air Force Civil Engineering Company Grade Officers, Tj E. Gabrielson

Theses and Dissertations

Voluntary turnover is a concern for the military and many other organizations from a financial and performance standpoint. This study applied grounded theory to code and network comments provided by CE officers in 2010. The results of this study found the most influential construct that predicts turnover intentions to be the relationship of OPSTEMPO influencing interrole conflict. This conflict is increased by the workload at home station due to under manning within CE. OPSTEMPO is an important aspect of a military member's decision to stay or leave the service because it was found to interact with a multitude of other …