Civil and Environmental Engineering Commons^™

Mitigation And Evaluation Of Alkali-Silica Reaction (Asr) And Freezing And Thawing In Concrete Transportation Structures, Richard Albert Deschenes Jr.

Graduate Theses and Dissertations

An evaluation of alkali-silica reaction (ASR) and freezing and thawing (F/T) in concrete transportation structures is presented along with mitigation methods for slowing the rate of deterioration in concrete. A combination of field and laboratory testing confirms ASR deterioration is exacerbated by exposure to F/T. Laboratory testing indicates an aggregate previously deemed inert to ASR, caused ASR deterioration in several concrete pavement and transportation structures. Existing standard test methods deem this aggregate safe for use in concrete. A modified test method shows the concrete can deteriorate rapidly when subjected to cycles of conditions promoting ASR and F/T. Several structures containing …

Optimization Of Concrete Mixtures For Use In Structural Elements, Waleed Almutairi

Graduate Theses and Dissertations

Portland cement is an essential ingredient in concrete. The use of cement is to enhance the strength as well as other hardened properties of concrete mixtures. Determining the accurate amount of cement is important because the required strength may not be achieved if not enough cement is used. By contrast, when using too much cement, concrete cracking may occur that leads to reducing durability. Researchers at the University of Arkansas (UA) have shown that many bridge decks achieve their 28 day design strength of 4000 psi by 7 days of age. Bridge decks having high strength may experience cracking, which …

Conditional Bias-Penalized Kalman Filter For Improved Estimation And Prediction Of Extremes, Miah Mohammad Saifuddin

Civil Engineering Theses - Archive

Kalman filter (KF) and its variants are widely used for real-time updating of model states and prediction in environmental sciences and engineering. Whereas in many applications the most important performance criteria may be the fraction of the times when the filter performs satisfactorily under different conditions, in many other applications the performance for estimation and prediction of extremes, such as floods, droughts, algal blooms, etc., may be of primary importance. Because KF is essentially a least squares solution, it is subject to conditional biases (CB) which arise from the error-in-variable, attenuation, effects when the model dynamics are highly uncertain, the …

Hydrocarbon Pool Fire Performance Of Reinforced Elastomeric Bearing Pads, Shashank Malal

Civil Engineering Theses - Archive

Bearing pads are used as support for bridge girders to transfer the reaction forces to the substructure. They are designed to accommodate high axial loads from girder, shear deformations due to lateral thermal expansion of girder, and rotational deformation. Apart from these deformations bearing pads may also be subjected to thermal stresses due to daily temperature variations and extreme events like fire hazard. Current design methods do not account for these thermally induced stresses in elastomeric bearing pads. The objective of this research is to study the hydrocarbon pool fire performance of elastomeric bearing pad. This research has three parts. …

Investigation And Proposed Remedy Of Vibration Problem In Industrial Crane System Due To Human Operation, Dustin C. Lorance

Civil Engineering Theses - Archive

A recent investigation of a crane system began when a facilities manager reported a runway beam under-going torsional vibration during operations. The investigation revealed the runway beam’s twisting was caused by resonance vibration due to “inching” of the crane hoist. A Fourier spectrum analysis revealed that one of the harmonic frequencies of this rhythmical motion coincided very close to the natural frequency of the crane system. The runway beam, although met strength requirements, failed to meet serviceability criteria due to the resonance vibration. Resonance vibration issues due to human activity in crane operation (inching, sway, etc.) is often encountered by …

Performance Of Lime- And Cement- Based Treatments Of Sulfate-Rich Soil Via Rc Testing, Azadeh Asghariastaneh

Civil Engineering Theses - Archive

Chemical treatment of expansive sulfate-rich soils, particularly lime- and cement-based methods, had been rather popular due to their relatively low cost and ready availability. However, over the last few decades, extensively documented pavement failures, mainly caused by excessive heaving and/or shrinkage of lime- and cement-treated subgrades with moderate-to-high sulfate content, have led to thorough investigations to assess the actual feasibility and effectiveness of calcium based stabilizers in sulfate-rich soils. Studies have concluded, with solid experimental evidence, that the calcium present in the chemical stabilizers react with the sulfate and alumina of the treated soil to form Ettringite, an expansive mineral …

Crack Healing In 304l Stainless Steel Using Additive Manufacturing And Friction Stir Processing (Fsp), Cameron Scott Gygi

Theses and Dissertations

Continuing an investigation on using FSP to heal stress corrosion cracks (SCC) in welds on nuclear reactors, this study seeks to use AM in addition to FSP to aid crack repair. Previous studies address that current repair technology on nuclear reactors involves the use of TIG welding which can allow helium atoms to aggregate and form voids at the grain boundaries. This weakens the material and renders the repair ineffective. Another previous study evaluated the effectiveness of FSP alone in repairing SCC which did have defects depending on the parameters used during FSP. This study evaluated the use of AM …

Making Public Health Performance Measures For Transportation Accessible To Practitioners, Ziaur Rahman

Civil Engineering Dissertations - Archive

Pollutants emitted into the atmosphere from static and mobile sources pose a threat to human health. The detrimental impact associated with air pollution varies by the type of pollutant, the magnitude, frequency and duration of exposure, and the associated toxicity. While stationary sources play an important role in air pollution, motor vehicle exhaust emissions represent the single largest source of regional air pollution in urban areas. Moreover, outdoor physical activity requires an increased oxygen level with an increase in exercise intensity. Research has shown that both the ventilation and deposition fractions increase significantly during outdoor activities, which may lead to …

Integrated Modeling Of Storm Drain And Natural Channel Networks For Real-Time Flash Flood Forecasting And Stormwater Planning And Management In Large Urban Areas, Hamideh Habibi

Civil Engineering Dissertations - Archive

Urban flash flooding is a serious problem in large highly populated areas such as the Dallas–Fort Worth metroplex (DFW). Being able to monitor and predict flash flooding at a high spatiotemporal resolution is critical to mitigating its threats and for cost effective emergency management. In this reserach, a high-resolution flash flood forecast system which operates in real time is developed for DFW using a gridded distributed hydrologic model and high-resolution quantitative precipitation estimates from the DFW Demostration Network of the Collaborative Adaptive Sensing of the Atmosphere (CASA) Program high-resolution X band radars and the National Weather Service (NWS) NEXRAD radar. …

Building Intelligence In The Automated Traffic Signal Performance Measures With Advanced Data Analytics, Tingting Huang, Subhadipto Poddar, Chris Aguilar, Anuj Sharma, Edward J. Smaglik, Sirisha Kothuri, Peter Koonce

Civil and Environmental Engineering Faculty Publications and Presentations

Automated traffic signal performance measures (ATSPMs) are an effort to equip traffic signal controllers with high-resolution data-logging capabilities and utilize this data to generate performance measures. These measures allow practitioners to improve operations as well as to maintain and operate their systems in a safe and efficient manner. Although these measures have changed the way that operators manage their systems, several shortcomings of the tool, identified by talking with signal operators, are a lack of data quality control and the extent of resources required to properly use the tool for system-wide management. To address these shortcomings, intelligent traffic signal performance …

Lifetime Reliability-Based Optimization Of Post-Tensioned Box-Girder Bridges, Tatiana García-Segura, Victor Yepes, Dan M. Frangopol, David Y. Yang

Civil and Environmental Engineering Faculty Publications and Presentations

This paper presents a lifetime reliability-based approach for the optimization of post-tensioned concrete box-girder bridges under corrosion attack. The proposed approach is illustrated by determining the optimal life-cycle cost and CO2 emissions of several initial designs of post-tensioned box-girder bridges with different objectives, i.e. the lowest initial costs, the longest corrosion initiation time, or the maximum safety. The study was conducted in two steps. Firstly, the Pareto set presents initial designs considering the cross-section geometry, the concrete strength, the reinforcing steel and the prestressing steel. Secondly, the maintenance optimization was conducted with the proposed method, aimed at minimizing the economic, …

Stress-Based Topology Optimization Of Steel-Frame Structures Using Members With Standard Cross Sections: Gradient-Based Approach, Navid Changizi, Mehdi Jalalpour

Civil and Environmental Engineering Faculty Publications

This article presents a computationally efficient methodology for stress-based topology optimization of steel frame structures with cross-sectional properties that are mapped from I-beam sections of a design manual. To account for the natural variability of the data, this mapping is achieved via quantile regression to derive continuous relationships between cross-sectional area (the design variable) and other section properties. These relationships are used for deriving the gradient of structural performance, which allows using computationally efficient gradient-based optimization schemes. Three frame structures are designed using the proposed algorithm, the resulting designs are compared with traditional compliance-based topology optimization algorithms, and changes in …

2017 Safety Belt Usage Survey In Kentucky, Kenneth R. Agent, Eric R. Green, Erin Lammers-Staats

Kentucky Transportation Center Research Report

The use of safety belts and child safety seats is a proven means of reducing injuries to motor vehicle occupants involved in traffic crashes. The objective of the survey summarized in this report was to establish a statewide safety belt usage rate in Kentucky for 2017. This rate can be compared to those determined from previous surveys. The 2017 statewide survey documents the continued increase in usage associated with the change in the law to allow primary enforcement and related education and enforcement.

Snow And Ice Removal Route Optimization In Kentucky, Benjamin L. Blandford, Erin Lammers-Staats, Eric R. Green

Kentucky Transportation Center Research Report

Each year the Kentucky Transportation Cabinet (KYTC) spends $40-$80 million removing snow and ice from the state’s roadways. Snow and ice removal are accomplished through a system of snow and ice removal routes that are designed to account for location and the attributes of trucks, facilities, materials, and roadways. To identify strategies that will improve and optimize KYTC’s snow and ice removal operations, Kentucky Transportation Center (KTC) researchers used ArcGIS and its Network Analyst extension to study the performance of the Cabinet’s current routing procedures. Building from this investigation, researchers developed optimized snowplow routings for four counties located in KYTC …

Simulation And Prediction Of The Groundwater Level In The Surrounding Area Of The Nebraska Management System Evaluation Area Site In Central Nebraska., Cesar Augusto Gomez Peña

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

An efficient water budget is necessary to develop sustainable practices in irrigated lands and determine future trends. Despite a lack of detailed knowledge, climate change is found to profoundly influence groundwater resources through changes in groundwater recharge, groundwater elevation, and groundwater flow processes. Prediction of the groundwater level (GWL) under a changing climate is essential to improve agricultural management.

The goal of this research is to predict the GWL from 2056 to 2060 in the surrounding area of the MSEA. In order to achieve the target, the first research task is to develop a groundwater flow model and then simulate …

Impacts Of Rail Transit Investments On Demographics And Land Use: 1990-2010, Aubrey Trinidad

All Theses

This paper studies the changes in land use and population characteristics around station areas following the building of rail transit stations in 14 major cities in the United States from 1990 to 2010. It answers the question: how have investments in US rail transit made since the 1990s affected land use and demographics? It also looks at the specific effects of investments on population density, race, and ethnicity, means of transportation, median housing value, median household income, vehicle access share, occupations, and land use represented by the share of multifamily versus single-family housing. Using block group level US census data …

The Macro-Modelling Of Steel Fiber Reinforced Concrete/Mortar Flexural Tensile Behavior And Mix Optimization For Flexural Strength., Li Liu

Electronic Theses and Dissertations

With the continuous advances in materials’ technology, the performance of the commonly used concrete building material has continued to improve. Compressive strengths exceeding 75 MPa are now being used in applications throughout the world. However, the concrete becomes less ductile and more susceptible to sudden failures with increases in its compressive strength. Although the behavior of concrete is generally governed by its compressive strength, its tensile strength, although much lower, is also important. This tensile strength impacts appearance, the serviceability and durability of concrete elements. In addition, minimum levels of tensile strength are required for many concrete applications including, earthquake …

A Smart Highway Work Zone Merge System Enabled By Connected Vehicles., Abdulmaged Algomaiah

Electronic Theses and Dissertations

Typical traffic control and operations at work zones usually are not very effective in mitigating the work zone bottleneck. A major reason is that the common early merge behaviors limits utilizing the available capacity in the closed lane, especially under moderate to high traffic demands. Recently, using late merge strategy is encouraged to prevent early merge behavior and fully utilize the closed lane and therefore increase capacity of work zone. The development of late merge strategy was not enough to substantially improve the situation due to the lack of compliance and communication among drivers. This thesis suggests and investigates a …

Cationic Surfactant Modification And Its Impact On The Engineering Behaviors Of Montmorillonite., Mohammad Ghavami

Electronic Theses and Dissertations

This study focuses on the microstructure of organoclays after organic surfactant modifications and the potential use in geoenvironmental engineering applications including waste containment in earthen barrier, rheological control agents for drilling fluid and soil stabilization. Organoclays, or clays modified by organic matters, are often synthesized by exchanging the naturally occurring interlayer inorganic cations (e.g., Na+, Ca²⁺) of the clay with organic cationic surfactants. In this research, montmorillonites intercalated with two quaternary ammonium surfactants, hexadecyltrimethylammonium (HDTMA+) and bis (hydrogenated tallow alkyl) dimethyl ammonium were used as the representative organo-rich, partitioning clays. The laboratory characterization techniques including XRD, TEM and …

A Shared Ontology Approach To Semantic Representation Of Bim Data, Mehrdad Niknam, Saeed Karshenas

Civil and Environmental Engineering Faculty Research and Publications

Architecture, engineering, construction and facility management (AEC-FM) projects involve a large number of participants that must exchange information and combine their knowledge for successful completion of a project. Currently, most of the AEC-FM domains store their information about a project in text documents or use XML, relational, or object-oriented formats that make information integration difficult. The AEC-FM industry is not taking advantage of the full potential of the Semantic Web for streamlining sharing, connecting, and combining information from different domains. The Semantic Web is designed to solve the information integration problem by creating a web of structured and connected data …

Remote Sensing Of The Environmental Impacts Of Utility-Scale Solar Energy Plants, Mohammad Masih Edalat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solar energy has many environmental benefits compared with fossil fuels but solar farming can have environmental impacts especially during construction and development. Thus, in order to enhance environmental sustainability, it is imperative to understand the environmental impacts of utility-scale solar energy (USSE) plants. During recent decades, remote sensing techniques and geographic information systems have become standard techniques in environmental applications. In this study, the environmental impacts of USSE plants are investigated by analyzing changes to land surface characteristics using remote sensing. The surface characteristics studied include land cover, land surface temperature, and hydrological response whereas changes are mapped by comparing …

Evaluation Of The Properties Of Rubberized Asphalt Binders And Mixtures, Kazem Jadidirendi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Rubber modified binder samples are tested and evaluated based on SHRP requirements. Best rubber content is suggested for modifying binder. Rubber modified asphalt mixtures were manufactured and tested. Based on Hveem stability and volumetric properties of asphalt mixtures, optimum binder content is evaluated and reported. Performance properties of asphalt mixtures made with various rubber size and method were analyzed and compared. An ultrasound measurement performed on asphalt mixture samples and the results were analyzed. It is discovered that rubber improves asphalt viscosity and resistance to rutting deformation. Rubber also increases asphalt’s dynamic modulus.

Life Cycle Assessment And Cost-Benefit Analysis Of Landfill Mining At The City Of Denton Landfill, Umme Zakira

Civil Engineering Theses - Archive

The concept of landfill mining has evolved the way of transforming the existing landfills from a final waste disposal site to a temporary storage location for the potentially valuable resources. The convergence of the sustainable material management and environmental protection issues have emerged the demand for the feasibility study of the landfill mining both in environmental and economic aspects considering the scope of potential resource recovery. Few studies have been conducted either on the environmental impacts on waste management (especially incineration) and operational options or generalized cost-benefit estimation for landfill mining project. Therefore, the present study aims to evaluate both …

Essays In Measuring, Controlling, And Coordinating Supply Chain Inventory And Transportation Operations, Payam Parsa

Graduate Theses and Dissertations

Supply chain collaboration programs, such as continuous replenishment program (CRP), is among the most popular supply chain management practices. CRP is an arrangement between two partners in a supply chain to share information on a regular basis for lowering logistics costs while maintaining or increasing service levels. CRP shifts the replenishment responsibility to the upstream partner to avoid the bullwhip effect across the supply chain. This dissertation aims to quantify, measure, and expand the benefits of CRP for the purpose of reducing logistics cost and improving customer service. The developed models in this dissertation are all applied in different case …

Engineering Applications Of Organic Surfactant Modified Bentonite In Sorptive Soil Barriers., Sadra Javadi

Electronic Theses and Dissertations

Earthen barriers such as CCLs and GCLs have been employed in geotechnical practices to provide a low permeability hydraulic barrier since long time ago. These types of barriers exhibited satisfactory performance for many applications such as landfills. The performance of low permeability barriers is based on the swelling potential of their component, which is mostly Na-bentonite, in contact with polar fluids such as water. However, the acceptable range of conductivity cannot be achieved by traditional earthen barriers when they are permeated by non-polar fluids such as gasoline. This phenomenon occurs due to the incompatibility of earthen barrier constituent with non-polar …

Resolving Spatial And Temporal Variability In Dissolved Organic Matter Characteristics Within Combined Agricultural And Stormwater Conveyances, Bryce A. Mihalevich

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In many urban areas, stormwater runoff can threaten the ecological health of streams and downstream water bodies. Due to the increased impervious nature of urban landscapes, runoff is more “flashy” and as a result, high concentrations of pollutants can be transported in shorter periods of time than in more natural environments. One pollutant of concern is dissolved organic matter (DOM). DOM is important within aquatic ecosystems, but excess amounts can cause depletion in dissolved oxygen concentrations and can negatively affect aquatic organisms. This study investigated changes in DOM quantity and sources within the Northwest Field Canal (NWFC), an urban water …

Subsurface Characterization Of Flexible Pavements Constructed Over Expansive Soil Subgrades And Selection Of Suitable Rehabilitation Alternatives, Kazi Moinul Islam

Boise State University Theses and Dissertations

Expansive soils present significant engineering challenges, with annual costs associated with repairing structures constructed over expansive soils estimated to run into several billion dollars. Volume changes in expansive soil deposits induced by fluctuations in the moisture content can result in severe damage to overlying structures. A flexible pavement section near the Western Border of Idaho has experienced recurrent damage due to volume changes in the underlying expansive soil layer; traditional stabilization methods have provided partial success over the years. The main objective of this research effort was to characterize the problematic soil layer contributing to the recurrent pavement damage and …

Effect Of Particle Size Distribution And Packing Characteristics On Railroad Ballast Shear Strength: A Numerical Study Using The Discrete Element Method, S. M. Naziur Mahmud

Boise State University Theses and Dissertations

Railroad infrastructure plays a significant role in sustaining the economy of a country, and facilitates fast, safe and reliable transportation of passengers as well as commodities. Significant capital investments are required for the construction and maintenance of a railroad network that is structurally and functionally adequate. The ballast layer is one of the main structural components of a conventional rail track system, and comprises coarse-grained unbound particles, often as large as in size. The ballast as a load-bearing layer resists train-induced stresses through particle-particle interaction. Accordingly, particle-size distribution and packing characteristics are important factors that govern the mechanical behavior of …

Development Of Lower Rio Grande River Water Quality Transportation Numerical Model For Bi-National River Management, Jose O. Gonzalez

Theses and Dissertations

Traditionally, water quality modelling has focused on modelling individual water bodies. However, water quality management problems must be analyzed at the larger scale to include influences from various water bodies that are interconnected. This paper provides a study on the hydrologic and quality transportation calculation by developing a hydrodynamic (unsteady state) channel routing model using a water-balanced approach. A one dimension Lagrangian river model was developed and applied to the 210 plus miles for the lower Rio Grande River Basin from the Falcon Dam to the head water of Brownsville that pours onto the Gulf of Mexico. This model can …

Archival Water-Level Measurements: Recovering Historical Data To Help Design For The Future, Stefan A. Talke, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Improving methods of assessing risk and designing structures to withstand extreme events and changing sea levels is a vital component of strategies for reducing risk to coastal resources and assets. An obvious approach to improving the statistical robustness of risk assessments is to increase the number, time span, and quality of available water-level data sets, and to assess trends and non-stationarity. In this report we discuss efforts to recover, digitize, and analyze hundreds of station-years of lost-and-forgotten tide data and other water-level measurements that extend back to the early 19th century. To date, more than 6,500 station-years of previously lost …