Civil Engineering Commons^™

Performance Of The Grout Curtain At The Kentucky River Lock And Dam No. 8, Robert C. Hatton

Theses and Dissertations--Civil Engineering

Karst bedrock conditions and deterioration of the lock and dam structures have resulted in significant leakage through, underneath, and around Lock and Dam No. 8 on the Kentucky River. During severe droughts, the water surface in Pool No. 8 has been observed to drop below the crest of the dam, resulting in water supply shortages and water quality issues for surrounding communities reliant on the pool. Presently, the primary purpose of Lock and Dam No. 8 is water supply. Pool No. 8 is currently where the cities of Nicholasville (Jessamine County, KY) and Lancaster (Garrard County, KY) draw their water. …

Numerical Modeling And Isotope Tracers To Investigate Karst Biogeochemistry And Transport Processes, Admin Husic

Theses and Dissertations--Civil Engineering

This dissertation investigated the physical and biogeochemical processes affecting the source, fate, and transport of sediment, carbon, and nitrogen within a highly-coupled fluviokarst system. Elemental and isotopic datasets were collected at surface and subsurface locations for both dissolved and particulate contaminant phases, new methodology regarding data collection was presented to the karst research community, an in-cave sediment transport model coupling physical transport with elemental and isotopic mass balances of carbon and nitrogen was formulated, pathway and process control on nitrate leaching from agricultural karst watersheds was assessed, and nitrate mobilization and fractionation were modeled using high frequency storm sampling and …

Direct Measurement Of Crosstie-Ballast Interface Pressures Using Granular Material Pressure Cells, Travis James Watts

Theses and Dissertations--Civil Engineering

The magnitudes and relative pressure distributions transmitted to the crosstie-ballast interface of railroad track significantly influences the subsequent behavior and performance of the overall track structure. If the track structure is not properly designed to distribute the heavy-axle loads of freight cars and locomotives, deficiencies and inherent failures of the crossties, ballast, or underlying support layers can occur, requiring substantial and frequent maintenance activities to achieve requisite track geometrical standards. Incorporating an understanding of the pressure distribution at the crosstie-ballast interface, appropriate designs can be applied to adequately provide a high performing and long-lasting railroad track. Although this can be …

High Resolution Sensing Of Nitrate Dynamics In A Mixed-Use Appalachian Watershed: Quantifying Nitrate Fate And Transport As Influenced By A Backwater Riparian Wetland, Alexandria Kosoma Jensen

Theses and Dissertations--Biosystems and Agricultural Engineering

As harmful algal blooms begin to appear in unexpected places such as rivers in predominantly forested systems, a better understanding of the nutrient processes within these contributing watersheds is necessary. However, these systems remain understudied. Utilization of high-resolution water quality data applied to deterministic numerical modeling has shown that a 0.42% watershed area backwater riparian wetland along the Ohio River floodplain can attenuate 18.1% of nitrate discharged from local mixed-use watersheds and improves in performance during high loading times due to coinciding increased hydrological connectivity and residence times of water in these wetlands. Loading from the Fourpole Creek watershed was …

Applying Machine Learning Techniques To Analyze The Pedestrian And Bicycle Crashes At The Macroscopic Level, Md Sharikur Rahman

Electronic Theses and Dissertations

This thesis presents different data mining/machine learning techniques to analyze the vulnerable road users' (i.e., pedestrian and bicycle) crashes by developing crash prediction models at macro-level. In this study, we developed data mining approach (i.e., decision tree regression (DTR) models) for both pedestrian and bicycle crash counts. To author knowledge, this is the first application of DTR models in the growing traffic safety literature at macro-level. The empirical analysis is based on the Statewide Traffic Analysis Zones (STAZ) level crash count data for both pedestrian and bicycle from the state of Florida for the year of 2010 to 2012. The …

Safety Investigation Of Traffic Crashes Incorporating Spatial Correlation Effects, Khalid Alkahtani

Electronic Theses and Dissertations

One main interest in crash frequency modeling is to predict crash counts over a spatial domain of interest (e.g., traffic analysis zones (TAZs)). The macro-level crash prediction models can assist transportation planners with a comprehensive perspective to consider safety in the long-range transportation planning process. Most of the previous studies that have examined traffic crashes at the macro-level are related to high-income countries, whereas there is a lack of similar studies among lower- and middle-income countries where most road traffic deaths (90%) occur. This includes Middle Eastern countries, necessitating a thorough investigation and diagnosis of the issues and factors instigating …

Fusing Freight Analysis Framework And Transearch Data: An Econometric Data Fusion Approach, Salah Uddin Momtaz

Electronic Theses and Dissertations

A major hurdle in freight demand modeling has always been the lack of adequate data on freight movements for different industry sectors for planning applications. Freight Analysis Framework (FAF), and Transearch (TS) databases contain annualized commodity flow data. The primary motivation for our study is the development of a fused database from FAF and TS to realize transportation network flows at a fine spatial resolution (county-level) while accommodating for production and consumption behavioral trends (provided by TS). Towards this end, we formulate and estimate a joint econometric model framework grounded in maximum likelihood approach to estimate county-level commodity flows. The …

Sinkhole Detection And Quantification Using Lidar Data, Amirarsalan Rajabi

Electronic Theses and Dissertations

The state of Florida is highly prone to sinkhole incident and formation, mainly because of the soluble carbonate bedrock which is susceptible to dissolution and groundwater recharge that causes internal soil erosions. Numerous sinkholes, particularly in Central Florida, have occurred. Florida Subsidence Incident Report (FSIR) database contains verified sinkholes with Global Positioning System (GPS) information. In addition to existing detection methods such as subsurface exploration and geophysical methods, a remote sensing method can be an alternative and efficient means to detect and characterize sinkholes with a wide coverage. the first part of this study is aimed at developing a method …

Optimizing Chlorine Disinfection By Chlorine Injection Location And Pipe Diameter Selection In A Water Distribution System, Margaret Neff

Dissertations, Master's Theses and Master's Reports

Due to a variety of factors chlorination is common water disinfectant for community-scale distribution systems. The town of Suyo, Peru was already equipped with a gravity fed water system and drip chlorinator which achieved 4-log inactivation of viruses throughout the town, however, it was not providing 3-log inactivation of giardia cysts at all points of the system.

This project used an EPANET model to determine and compare the potential benefits of changes which could be made to the pre-existing water system in Suyo.

The model was used to compare current operating conditions of the Suyo system, 1.5 mg/L chlorine addition …

Understanding Large-Scale Natural Mine Water-Geologic Formation Systems For Geothermal Applications, Ting Bao

Dissertations, Master's Theses and Master's Reports

Geothermal energy recovery from flooded mines has been gaining momentum worldwide. Numerous mines are flooded after their closure, either naturally or artificially, in which the water in the mines can be heated by the surrounding geologic formations due to geothermal gradients, leading to sizeable man-made reservoirs of warm water. Such mine water, therefore, can be treated as a renewable geothermal resource for heating/cooling buildings, which has the potential to benefit over millions of people in the United States and much more around the world. Though some real projects and/or installations launched worldwide for the use of flooded mines for geothermal …

Initial Investigation Of Generating Electricity From Concrete, Mohamed Abdel-Raheem, Ofsman Quintana

Civil Engineering Faculty Publications

Cement heat of hydration (HH) can be problematic especially in mass concrete structures as it causes thermal stresses that can lead to failure. Previous and current research has focused on minimizing the HH and mitigating its effects. The methods currently used for treating the HH in mass concreting varies between using: adding supplementary material to concrete, precooling of aggregates and mixing water, post-cooling of concrete, insulation of concrete members, and placement of concrete in thin lifts. These methods result in adding more cost and time to the construction project. This research sheds the light on a new approach in treating …

Probabilistic Analysis And Resistance Factor Calibration For Deep Foundation Design Using Monte Carlo Simulation, Thuy Vu, Erik Loehr, Douglas Smith

Civil Engineering Faculty Publications

The method of incorporating the sources of parameter uncertainty is crucial when conducting probabilistic analysis for service limit state (SLS) design of a deep foundation. This paper describes the method of using Monte Carlo simulation for probabilistic analyses and for calibration of resistance factors of drilled shafts at SLS. The paper presents discussions on the finding of an impossible case, where the different combinations of load, variability of soil strength and target probability of failure made it impossible to calibrate the SLS resistance factors. Resistance factors for drilled shafts in shale are introduced, and were found to be responsive to …

A Two-Dimensional Finite Element Model Of The Grain Boundary Based On Thermo-Mechanical Strain Gradient Plasticity, Yooseob Song, George Z. Voyiadjis

Civil Engineering Faculty Publications

In this work, a two-dimensional finite element model for the grain boundary flow rule is developed based on the thermo-mechanical gradient-enhanced plasticity theory. The proposed model is temperature-dependent. A special attention is given to physical and micromechanical nature of dislocation interactions in combination with thermal activation on stored and dissipated energy. Thermodynamic conjugate microforces are decomposed into energetic and dissipative components. Correspondingly, two different grain boundary material length scales are present in the proposed model. Finally, numerical examples are solved in order to explore characteristics of the proposed grain boundary flow rule.

Construction Methods Used For Controlling Temperature In Mass Concrete Structures, Mohamed Abdel-Raheem, Ofsman Quintana, Melissa Morales, Yahaira Marroquin-Villa, Dalinda Ramos, Sylvia Hernandez

Civil Engineering Faculty Publications

The hydration of cement can release a substantial amount of heat that can be problematic in mass concrete structure. This heat of hydration (HH) can produce thermal stresses that can crack the concrete and compromise the integrity of the structure leading to its failure. Throughout the years, different methods have been developed in order to mitigate the negative effects of the HH on mass concrete structures. This study presents a comprehensive review of the previous methods documented in the literature that have been utilized in controlling the temperature rise due to the HH in mass concreting. The reviewed methods were …

Hydrothermal Carbonization Of Food Waste For Nutrient Recovery And Reuse, Ifeolu M. Idowu

Theses and Dissertations

Food waste represents a rather large and currently underutilized source of potentially available and reusable nutrients. Laboratory-scale experiments evaluating the hydrothermal carbonization of food wastes collected from restaurants were conducted to understand how changes in feedstock composition and carbonization process conditions influence primary and secondary nutrient fate. Results from this work indicate that at all evaluated reaction times and temperatures, the majority of nitrogen, calcium, and magnesium remain integrated within the solid-phase, while the majority of potassium and sodium reside in the liquid-phase. The fate of phosphorus is dependent on reaction times and temperatures, with solid-phase integration increasing with higher …

Understanding Geopolymerization Process For Enhancement Of Mechanical Properties Of Fly Ash Based-Geopolymer Concrete, Lateef Najeh Assi

Theses and Dissertations

Concrete is a major construction material that is largely made up of cement. Unfortunately, the manufacturing process for the cement currently used to produce concrete releases a great deal of CO2, which endangers the environment. Hence, finding alternatives to ordinary Portland cement is of extreme importance. The intellectual contribution of this dissertation is the development of an improved understanding of the geopolymerization process so that the compressive strength of cement can be maximized while the need for external heating is minimized. The intent is to create a substance to replace commonly used cement without sacrificing other beneficial properties. The first …

The Transport Of Non-Spherical Particles In A Simulated Ocean Environment, Hannah Reed

REU Final Reports

Plastic particles contaminating the world’s oceans and accumulating in oceanic gyres has become a ubiquitous problem and the solution involving how to clean up the debris efficiently has still not been found. One particular issue is understanding where the greatest densities of debris may be. It is known that floating trash will tend to accumulate in large circular systems of ocean water called gyres, however these areas span thousands of miles of ocean. The present study aims to understand the transport of anisotropic particles in conditions similar to an oceanic environment using experimental methods in an effort to better predict …

Building Information Modeling (Bim) Impact On Construction Performance, David D. John

College of Graduate Studies: Theses & Dissertations

This study is designed to address the need for having a measure for Construction Performance on BIM-assisted construction projects. Through this study a new Construction Key Performance Indicator (CKPI) matrix is identified and created by the author. The CKPI could be used to assess BIM-assisted projects. Utilizing a sequential mixed methodology approach, academic and practitioner perspectives are assessed. A qualitative content analysis and quantitative descriptive analysis based on demographics are conducted to establish a better understanding of BIM and Construction Performance. The academic perspective is used to assess the relevance of BIMM and CKPI indicators, and the practitioner perspective is …

Designing And Testing 3-D Printed Wafer-Box With Embedded Pzt Sensors To Identify The Shape Effect On Energy Harvesting, Ahmad Jami Safayet

College of Graduate Studies: Theses & Dissertations

Piezoelectric energy has been recently paid attention in the field of alternative energy. Day by day the traditional energy sources including Coal tar and oils are becoming scarce. People are heading to an alternative energy source to meet the future energy demand. Piezoelectric energy is one of the competitive energy sources compared to the conventional renewable energy sources including solar, wind, and geothermal power and so on. This energy production method bears enormous research potential because it can be used as the roadway for a new method of power generation. This research project aimed to identify which shaped wafer-box produced …

Field Implementation Of Cement-Based Composite Strengthening Technologies, Michael Andrew Janke

Masters Theses

"With infrastructure continuing to age, technologies are being developed to strengthen structures as a more sustainable option than replacement. The use of fiber-reinforced cementitious matrix (FRCM) strengthening systems is a promising new technology for adding flexural and shear capacity to existing reinforced concrete members. While cement based systems with carbon, PBO, and steel have all been implemented in a lab setting, there is not research data available for installation in the field. FRCM composites have advantages over more widely used fiber reinforced polymer (FRP) composites such as heat resistance and compatibility with concrete substrate. FRP systems have previously been field …