Civil Engineering Commons^™

Achieving Sustainability In Urban Transit And High-Occupancy Vehicle Systems Through Emerging Technologies And Operations, Ruixiao Sun

Theses and Dissertations

It is critical to reduce road transportation emissions, as it is the major source contributing to greenhouse gas emissions (GHGs) and air pollution. However, the increasing travel demand due to the rise of population and economy makes the task challenging. Mathematically, road transportation emissions can be minimized in the manner of reducing total vehicle miles traveled (VMT) and lowering vehicle emission rate. Many strategies have been proven viable for achieving transportation sustainability. For example, the total VMT can be reduced by switching low-occupancy transportation modes (i.e., driving alone) to high-occupancy transportation modes (i.e., public transit, ridesharing). The development of alternative-fuel …

Cyclic Response And Liquidfaction Behavior Of Gravelly Soils, Pitak Ruttithivaphanich

Theses and Dissertations

Cyclic response and liquefaction behavior are soil mechanisms under earthquake conditions. The study of dynamic soil response is important to evaluate soil behaviors under dynamic loading for a wide range of strains. Soil liquefaction phenomena involving a significant reduction in the strength and stiffness of saturated cohesionless soils has caused catastrophic ground failure in numerous earthquakes. Liquefaction mostly occurs in sand, but liquefaction of gravelly soil has been observed. To date, only a few studies have focused on the liquefaction of gravelly soils; hence, research data is limited. This research aims to improve the understanding of cyclic response and liquefaction …

Physico-Mechanical Characterization Of Prototype Earth Block Material For Constitutive Modeling, Erika Lorena Rengifo-López

Theses and Dissertations

The comprehensive understanding and experimental characterization of the overall compressive behavior of earth masonry block materials, such as compressed and stabilized earth blocks (CSEBs), are essential for developing analytical and numerical tools to predict the mechanical response and designing earth masonry structures. Furthermore, advancing the understanding of the extent of the influence of testing parameters on the material's response, such as specimen geometry, is a critical step towards standardization.

CSEBs are produced by compressing a mixture of soil, water, and a stabilizer (e.g., Portland cement). The heterogeneity of the material accrues from the variety of soil particle morphology and potential …

Structural Health Monitoring Of Fatigue Cracks For Steel Bridges With Wireless Large-Area Strain Sensors, Sdiq Anwar Taher, Jian Li, Jong-Hyun Jeong, Simon Laflamme, Hongki Jo, Caroline Bennett, William N. Collins, Austin Downey

Faculty Publications

This paper presents a field implementation of the structural health monitoring (SHM) of fatigue cracks for steel bridge structures. Steel bridges experience fatigue cracks under repetitive traffic loading, which pose great threats to their structural integrity and can lead to catastrophic failures. Currently, accurate and reliable fatigue crack monitoring for the safety assessment of bridges is still a difficult task. On the other hand, wireless smart sensors have achieved great success in global SHM by enabling long-term modal identifications of civil structures. However, long-term field monitoring of localized damage such as fatigue cracks has been limited due to the lack …

Oxidized Graphitic Nano-Amendment Of Cement Composites: Exploring Truly Low Concentrations And Novel Particle Morphologies, Shohana Iffat

Theses and Dissertations

Oxidized graphitic nanoparticles such as multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs), can produce enhancements in physicomechanical properties of cement composites that are relevant to structural and durability performance, provided that said nanoparticles are well dispersed in the composite. Lower-bound MWCNT concentrations are reported in the literature in the range 0.01-0.05% in weight of cement (wt%). Such concentrations may not be costeffective for practical applications and may also be excessive since they would result in a nanoparticle surface area at or above 105 m2 for 1 m3 of cement paste, or 104.5 m2 for 1 m 3 of concrete, …

Classification Of Acoustic Emission Data Into Load Steps Using An Artificial Neural Network, Allen Ross

Theses and Dissertations

The average age of bridges in South Carolina is approaching 40 years, very close to the 50-year service life. Almost 11% of the bridges in South Carolina are rated as structurally deficient, greater than the national average of 7.5% (South 2021). Health monitoring is the concept that in-situ sensors can continuously monitor civil structures and send real time signals of damage. This process allows for automation and could save time and money on the inspection and load rating of bridges. Health monitoring requires sensors that provide uninterrupted data without sacrificing the functionality of the bridge. A prime candidate for this …

The Effect Of Concrete Material Properties On Rigid Pavement Design In South Carolina, Nicolet Anne Devine

Theses and Dissertations

This thesis presents the effect of concrete material inputs on rigid pavement design in the state of South Carolina. The impact of concrete strength input parameters in the historical AASHTO pavement design method and MEPDG method is investigated using three newly constructed concrete sections, I-85 in Cherokee County, I-20 in Lexington County, and I-85 in Spartanburg County. Strength data obtained from the sections were the result of QA/QC testing provided by the SCDOT during construction, as well as from UofSC laboratory testing. The compressive strength data from these tests was correlated to the elastic modulus and modulus of rupture (which …

Coalitional Game Theory For Stormwater Management And Green Infrastructure Practices, Carly Lawyer

Theses and Dissertations

As global warming and climate Variability bring about more frequent and intense rainstorms and accelerate sea level rise, our social and built environments are at heightened risk of flood induced damages and consequent costs. This is particularly true for coastal areas, facing the coupled effects of these threats while serving as home to people, businesses, unique landscapes, and historic landmarks. Complex decisions at all levels of government and community planning stand to benefit from increased understanding of possible outcomes and pathways resulting from decentralized human behavior and decision making in the realm of water resources engineering and management. Game theory …

Cyclic Triaxial Testing To Evaluate Factors Affecting The Unsaturated Cyclic Behavior Of A Silty Sand, Zachary R. Howard

Theses and Dissertations

This study assesses the cyclic resistance of a non-plastic silty sand, representative of a common mine tailings material. Two series of unsaturated cyclic triaxial tests were conducted, which varied wetting and drying path specimen preparation techniques, initial matric suction, initial net normal stress, and cyclic stress ratio. Specimens prepared using the wetting path experienced significantly higher cyclic resistance than those prepared using the drying path. Specimens that were exposed to higher initial matric suction values experienced higher cyclic resistance than those consolidated with lower initial matric suction values. Initial net normal stress was found to contribute more to specimen cyclic …

Combined Effects Of Welding Residual Stress And Thermal Expansion In Cwr, Brennan Gedney

Theses and Dissertations

Continuously welded rail with flash-butt welded joints has become standard practice for railway construction around the world. Through the process of welding, a residual stress field develops in the joint which typically remains in the rail through its service life. Consequently, the total stress is altered locally in the presence of operation induced stresses. One such stress develops due to thermal expansion of the rail during the daily and seasonal solar radiation heating cycle. This paper seeks to ascertain the combined effects of welding residual stress with thermal expansion through computer simulations. This is aimed at two objectives: determining whether …

Evaluation Of A Trigonometric Grey Model For Estimating And Predicting Pavement Condition, Amara Kouyate

Theses and Dissertations

States, counties, and municipalities rely on pavement performance curves to forecast future pavement conditions in their jurisdictions. Accurate prediction is essential for budget planning and the identification of candidates for rehabilitation. This study investigates the use of a grey model (GM) to estimate and predict pavement conditions. An advantage of the GMs is that they do not require a large sample size for model estimation. This aspect is important since smaller towns and municipalities often cannot afford to collect pavement condition data frequently due to cost. There are other situations where sample size may be limited, such as using project-level …

Impact Of Graphene On Microstructure And Compressive Strength Of Cement Mortars Utilizing Two Different Dispersion Methods, Elhussien Khaled Elbatanouny

Theses and Dissertations

Carbon-based nanomaterials are currently used to reinforce cement-based composite materials based on their superior properties. This study investigates the mechanical property (compressive strength) of cement mortars incorporated with pristine graphene. The dosages of graphene materials used were 0.01%, 0.02%, 0.03%, and 0.04% by weight of cement. Moreover, this study compares two dispersion techniques: ultrasonication with surfactant coating and mechanical blending with surfactant coating to promote the use of graphene in cement mortars. A commonly used polycarboxylate superplasticizer Sika-Viscocrete Ultra 2100, was used as a dispersant agent (surfactant) of graphene with a surfactant to graphene weight ratio of 9 to 1. …

Identification Of Structural Signature Responses From Response Time Histories Using B-Spline Impulse Response Techniques, Shadhan Ahmed Al Kharusi

Theses and Dissertations

Structure Health Monitoring (SHM) is an essential practice for ensuring the safety of people and the structures itself. For this purpose, variety of global and local damage detection methods have been used to investigate damages. Global damage detection focus on identifying damage in early stages while local damage detection related to damage location, severity, and prediction of the remaining of the structure. Any damage in structure leads to a change to the properties and characteristics of the dynamic response.

Existing methods uses modal-based and response-based for damage detection. Both have several shortcoming associate with sensitivity of the damage and measurement …

Predicting Pavement Structural Condition Using Machine Learning Methods, Nazmus Sakib Ahmed

Theses and Dissertations

State departments of transportation recognize the need to incorporate pavement structural condition in their pavement performance models and/or decision processes used to select candidate projects for preservation, rehabilitation, or reconstruction at the network level. However, pavement structural condition data are costly to obtain. To this end, this paper develops and evaluates the effectiveness of two machine learning methods, Random Forest (RF) and eXtreme Gradient Boosting (XGBoost), for predicting a flexible pavement’s structural condition. The aim is to be able to predict whether a pavement section’s structural condition is poor or not based on Annual Average Daily Traffic (AADT), truck percentage, …

Development Of A First-Generation Prototype Laboratory System For Rail Neutral Temperature Measurements, Ellie Yi-Hsien Chao

Theses and Dissertations

Modern railway tracks worldwide standardize the use of Continuous Welded Rail (CWR) due to its ability to prevent disadvantages associated with rail joints in a track. CWR is laid when the rail is free of thermal stresses, also known as Rail Neutral Temperature (RNT). RNT is controlled in the CWR installation procedure; however, over time, the temperatures deviate from the RNT. The deviation causes significant thermal stresses introduced in the longitudinal direction of the rail, leading to potential failures such as pull-apart and buckling, causing track integrity and safety of train operation. The most significant potential failure is track buckling …

Computer Vision-Based Automatic Railroad Crossing Monitoring And Track Inspection, Feng Guo

Theses and Dissertations

Currently, there are many imminent challenges in the railroad infrastructure system of the United States, impacting the operation, safety, and management of railroad transportation. In this work, three major challenges which are overcrowded traffic congestion at the grade crossing, low-efficiency and accuracy on inspection of missing or broken rail track components, and dense rail surface defects without quantification, respectively are studied. The congested railroad grade crossing not only introduces significant traffic delays to travelers but also brings potential safety concerns to the first responders. However, limited studies have been devoted on developing an intelligent traffic monitoring system which is significant …

Towards Intelligent Structural Health Monitoring Of Infrastructure Systems: An Interdisciplinary Study Of Acoustic Emission Monitoring, Numerical Simulation, And Artificial Intelligence, Li Ai

Theses and Dissertations

Some complex infrastructure systems, such as nuclear facilities and bridges, are subject to structural damage due to environmental erosion, material deterioration, and other factors after long periods of use. Stress corrosion cracking (SCC) and alkali-silica reaction (ASR) have been identified as the primary degradation mechanisms for steel and concrete structures in nuclear facilities and bridges. Ensuring the integrity and operational safety of structures during their lifetime is an important task. Nondestructive methods and structural health monitoring can be used to detect damage caused by SCC and ASR instead of conventional visual inspection. Among the nondestructive methods, acoustic emission (AE) is …

Removal Of Heavy Metals Using Novel Adsorbent Materials, Lesley Joseph

Theses and Dissertations

Heavy metal contamination is a growing concern throughout the world, particularly as industrial and urban activities have increased. Inadequate water and wastewater treatment, coupled with increased industrial activity, have led to increased heavy metal contamination in rivers, lakes, and other water sources in developing countries. To address these concerns, a significant amount of research has been conducted on various novel adsorbents to evaluate their ability to remove heavy metals. Thus, in this study, MIL-100(Fe) and MIL-101(Cr) are fabricated and investigated to determine their ability to remove copper (Cu2+), cadmium (Cd2+), and lead (Pb2+) from aqueous solution. The experimental data fit …

Fate Of Nitrogen And Effectiveness Of Evaporation On Managing Leachate In Collection And Storage Ponds: A Case Study At The Three Rivers Solid Waste Authority Regional Landfill, Kaitlen Rose Drafts

Theses and Dissertations

Treatment of leachate from municipal solid waste (MSW) landfills can be complex and difficult, due to the variety of contaminants present. The purpose of this work was to evaluate the fate of nitrogen and effectiveness of leachate evaporation in a leachate storage and collection pond at the Three Rivers Solid Waste Authority (TRSWA) MSW landfill in Jackson, South Carolina. This was accomplished by determining the fate of nitrogen species in the pond, exploring effect of the site’s Lilypad droplet sprayer system on ammonia-nitrogen, and exploring potential to reduce overall quantity of leachate to be treated through evaporation from the pond. …

Rehabilitation Of Timber Piles Using Fiber Reinforced Polymers Analyzed With Acoustic Emission, Rebekah Marie Krol

Theses and Dissertations

Assessing the current state of infrastructure and implementing strengthening or rehabilitation methods on old or damaged members is important to ensure safety and longevity of structures. Non-destructive testing is an important tool for localizing and characterizing damage in structures, especially structures that are more susceptible to damage because of age or environment. In addition to locating inadequate members, it is essential to have a repair technique in place so that the structure can continue to be used in a safe manner.

This study aims to review the use of acoustic emission for evaluating damage obtained in timber piles subjected to …

Physical Modeling Of Backward Erosion Piping Phenomenon In A Geotechnical Centrifuge, William Fernando Ovalle Villamil

Theses and Dissertations

Backward erosion piping is a mechanism of internal erosion that has been widely recognized as a potential hazard for water-retaining structures, such as dams and levees, that are founded on granular materials. Backward erosion piping initiates toward the downstream zone of the structure by the concentration of flow at an exit point acting as drainage, which leads to a localized loosening of the soil and eventually to a continuous migration of grains from the foundation following a piping path pattern. Such piping path extends backward toward the impoundment once a certain critical hydraulic condition is met, resulting in the loss …

Use Of Geospatial Technique To Estimate Traffic Volume On South Carolina Roads, Ryan Andrew Devine

Theses and Dissertations

Data from the Federal Highway Administration (FHWA) indicates that there is an increase in the number of vehicles on already congested roadways. For a department of transportation (DOT) to keep up with this increased demand, it is necessary for them to continuously collect and monitor traffic volume on the roads they maintain. One of the most important parameters that DOTs collect and use for traffic engineering and transportation planning studies is annual average daily traffic (AADT). The DOTs are also required to collect and report AADTs to the Federal Highway Administration annually as part of the Highway Performance Monitoring System …

Evaluating The Stabilization Of Gypseous And Gypsiferous Sands Using Different Chemical Additives To Mitigate Gypsum Dissolution, Mohammed Kamil Faris

Theses and Dissertations

Gypsum, which is dihydrate calcium sulfate, (CaSO4.2H2O), is widely available in different sizes, from the size of a rock to the size of a few micrometers as a mineral, in different types of soils. It is primarily found mainly in arid and semi-arid areas around the world at different depths. Soils with gypsum and even gypsum rocks are very hard in their dry state. However, these soils and rock will experience remarkable dissolution upon wetting.

The dissolution phenomenon, which takes place in soils that contain gypsum, creates different geotechnical problems within the soil’s profile, along with foundation issues for structures …

Evaluation Of Temporal Damage Progression In Concrete Structures Affected By Asr Using Data-Driven Methods, Vafa Soltangharaei

Theses and Dissertations

Alkali-silica reaction (ASR) is a chemical reaction, which causes damage in concrete structures such as bridges, dams, and nuclear containments and powerplant structures. The ASR-induced damage may endanger the integrity and serviceability of structures. Several methods such as visual inspection, petrographic analysis, demountable mechanical strain gauges, and cracking index have been utilized for study the effect of ASR on structures, which are not always efficient in early damage detection and some are destructive and prohibited in nuclear structures. Nondestructive methods and structural health monitoring techniques can be alternatives for the condition assessment of structures. Among the nondestructive methods, acoustic emission …

Structural Design Of Pool House In The City Of Columbia, Nathan F. Gates

Senior Theses

This report presents a structural design for a one-story pool house in the City of Columbia. The most important part of the project was determining critical horizontal and vertical loads, and designing each member in accordance to those governing loads. The loads we analyzed were dynamic, dead, live and seismic. By means of the LRFD method, the greatest possible load combination was calculated, combining the previously mentioned loads. These load combinations were different for each analysis, as the loading pressures will change depending on what structural system is being analyzed. This comprises the large part of the report and of …

Experimental Investigation Of Hydraulic Effects On Unsaturated Soils Behaviors, Muwafaq Awad

Theses and Dissertations

Geo-structures are frequently constructed in or on soils with unsaturated conditions and are subjected to variations of moisture contents due to seasonal changes. Even though unsaturated soil mechanics have been established for several decades, it has not been fully implemented in practice today because of a lack of understanding of the interaction between the soil, water, and air phases. Many experimental research studies have been conducted to improve the understanding of unsaturated behavior but these studies are typically limited to small soil elements tested under fully drained conditions. The goal of this research is to evaluate the effect of hydraulics …

A Non-Contacting System For Rail Neutral Temperature And Stress Measurements, Katelyn Knopf

Theses and Dissertations

Continuous Welded Rail (CWR) has become the standard in modern railway track construction around the world because it alleviates well-documented disadvantages of rail joints in a track. CWR practice results in long segments of continuous rail in the track that will develop significant thermal elongation. To avoid the use of impractical large thermal expansion joints and limit the expected thermal elongation, the rail is anchored to the ties. Consequently, the rail is exposed to higher thermal stress demands as the rail temperature varies. At the time a CWR is laid, the rail is free of thermal stresses; the temperature at …

Modeling Particle Dispersal In Bedload Dominated Settings, Sanaz Borhani

Theses and Dissertations

Tracer particles are used to study bedload transport in gravel bed rivers. One of the advantages associated with their use is that they allow for direct measurements of particle entrainment rates in bedload transport and particle displacement. The main issue in field studies with tracer particles is the difference between tracer short term and long term behavior. This difference is due to the fact that particles undergo vertical mixing or move to less active locations such as bars or even floodplains. For these reasons the mean tracer velocity decreases over time. This phenomenon has been called tracer slowdown and it …

The Study Of Flow Hydrodynamics And Transport Processes Over Mixed Bedrock-Alluvial Reaches, Mohammad Sadegh Jafarinik

Theses and Dissertations

Research efforts on mixed bedrock-alluvial rivers primary focused on the bedrock incision and very few studies investigated the alluvial morphodynamics of such systems. To the best of my knowledge none of these models have been considered the spatial variability of the sediment grain size of the bed surface in mixed bedrock-alluvial reaches and very few models focused on the spatial changes in alluvial cover within these reaches. Furthermore, a perusal of the literature on mixed bedrock-alluvial river morphodynamics reveals that very little information is available on 1) bedform geometry and flow resistances and 2) sediment sorting patterns in presence of …

Damping In Transient Pressurized Flows, Sahad Salim Elyass Khilqa

Theses and Dissertations

Piping systems are commonly designed to withstand the first transient pressure peak, which is unaffected by dissipation. However, for multiple operations of control equipment, e.g., pump start-up following pump shutdown, load acceptance following load rejection on hydraulic turbines, etc., an accurate prediction of the dissipation of pressure oscillations is needed to determine a suitable time for the second operation. For this purpose, a method is presented to compute the dissipation of pressure oscillations in piping system following a simple procedure used for computing the dissipation of vibrations of bridges and other structures. Similar to structural engineering, this method is simple …