Engineering Commons^™

Pilot-Scale Test Of Water Wash Carbon Dioxide Absorption System For Purifying Landfill Gas At Jones Island Wastewater Reclamation Facility, Rebecca Schruender

Theses and Dissertations

Biogas, a product of the digestion of organic material, consists primarily of methane and carbon dioxide. By purifying raw biogas, or removing the carbon dioxide, it can be upgraded to biomethane, which can be used to generate heat and electricity or as a substitute for natural gas. An effective method of biogas purification is the water wash process, which consists of an absorption column in which a stream of biogas runs counter-current to a stream of water. The carbon dioxide dissolves in the water, increasing the methane concentration of the gas. A pilot scale system was operated at Jones Island …

Underwater Particle Image Velocimetry (Piv) Measurement Of Turbulence Over Mussel Bed In A Deepsite Of Lake Michigan, Tong Jin

Theses and Dissertations

The influence of the benthic filter feeders, such as bivalves, on ecosystem plankton, and nutrient dynamics is considered significant in shallow marine and freshwater systems. Recent indirect evidence showed that the profundal quagga mussels (Dreissena rostriformis bugensis) have fundamentally altered energy flow and dynamics of nutrients and phytoplankton in Lake Michigan and other Great Lakes. To investigate the phytoplankton grazing rate of the quagga mussel and the mussel siphon currents induced bio-mixing, a self-contained in situ Underwater Particle Image Velocimetry was developed to measure the turbulence structure and the turbulent diffusion coefficient immediately above the profundal quagga mussel covered substrate …

Application Of Survival Analysis Techniques To Probabilistic Assessment Of Fatigue In Steel Bridges, Azam Nabizadehdarabi

Theses and Dissertations

The fatigue of engineering materials under repetitive loading is a significant issue affecting the design and durability of components and systems in a variety of engineering-related applications including civil, mechanical, aerospace, automotive, and electronics. Many factors can affect the service life of a component or system under repetitive loading, such as the type of structure, loading, connection details, stress state, peak stress or stress range, surface condition, temperature, and environmental exposure. Currently, there is no comprehensive probabilistic approach that can systematically address all the factors that contribute to fatigue on a single mathematical platform. However, advanced analysis techniques developed for …

Multi-Facet Retrofit Approach To Improve Energy Efficiency Of Existing Class Of Single-Family Residential Buildings In Florida, Kwame Baffour Ohene Amoah

Theses and Dissertations

There are many approaches to incorporate energy efficiency measures (EEMs) into building through retrofit projects. Single-family buildings are an essential target for energy improvements because of their energy-saving potential and considerable market share. This study evaluates energy savings and cost-effectiveness of individual retrofit options. It proposes energy efficiency measures for an existing class of single-family homes constructed between the years of 1950 and 1970. The study uses a baseline building located in Melbourne, FL, as a case study. A survey via clustering data mining was conducted on Florida Single-Family Residential (SFR) buildings (1950 – 1970) to establish patterns of construction, …

An Advanced Approach For Contract Time Determination In Highway Projects, Cuauhtemoc Torres Cantu

Theses and Dissertations

In project management, finishing a project on schedule is one of the most important aspects. The Texas Department of Transportation (TxDOT) has been experiencing delays in some projects that can be accounted to an inaccurate project time estimation process. This research presents the development of a user-friendly and comprehensive computer-based contract time determination system. The enhanced system implements probabilistic scheduling techniques such as Program Evaluation and Review Technique, and Monte Carlo Simulation. Additionally, the application of a lognormal two-point PERT method is explored in this study. The new system proposes the use of a database of production rates based on …

Splice Performance Of #6 Reinforcing Bars In Masonry With Self-Consolidating Grout, Annie Ruth Nielson

Theses and Dissertations

Reinforced masonry grouted using self-consolidating grout (SCG) is a relatively new and economically competitive option for construction, providing advantages such as reduced construction time, decreased noise and vibration, and reliable consolidation. However, SCG has different properties than conventional grout and its performance should be verified using current governing code requirements. The purpose of this research program was to determine the development length of spliced reinforcing bars in masonry grouted with SCG.Twelve masonry panels, four courses high and two and a half blocks wide, were constructed using 8-inch concrete masonry units, each with two pairs of vertically spliced #6 reinforcing bars. …

Dynamic Vehicular Trajectory Optimization For Bottleneck Mitigation And Safety Improvement, Wenqing Chen

Theses and Dissertations

Traffic bottleneck is defined as a disruption of traffic flow through a freeway or an arterial, which can be divided as two categories: stationary bottleneck and moving bottleneck. The stationary bottleneck is mainly formed by the lane drops in the multi-lane roadways, while the moving bottleneck are due to the very slowing moving vehicles which disrupt the traffic flow. Traffic bottlenecks not only impact the mobility, but also potentially cause safety issues.

Traditional strategies for eliminating bottlenecks mainly focus on expanding supply including road widening, green interval lengthening and optimization of intersection channelization. In addition, a few macroscopic methods are …

Optimizing Hydrogen Sulfide Removal And Biogas Production Using The Water Wash Method, Brian Leightner

Theses and Dissertations

Biogas forms from decomposing organic material in agricultural digesters, landfills, and wastewater treatment plant digesters. Biogas is mostly composed of methane, and can be used as a carbon-based fuel. Microorganisms that consume organics in these waste streams also produce hydrogen sulfide (H2S) as part of the biogas, in varying trace amounts. H2S is corrosive to engines and pipes for machinery, a human health hazard when inhaled, and an aquatic hazard when dissolved in water. Water washing is an absorption process that dissolves hydrogen sulfide and other water soluble compounds in this process and carries it away from the gas, thereby …

Evaluating Measurement Of Strain Hardening Method For Mechanical Assessment Of Geomembrane Service Life In Msw Landfills, Alaa Alsharaballi

Theses and Dissertations

The increased household production result in more construction of municipal solid waste (MSW) landfills and lagoons. One major part of these engineering projects is high-density polyethylene (HDPE) geomembrane. Geomembrane is an impermeable layer that used along bottom and sides of landfills and lagoons to contain the leachate and to protect the groundwater. Although of their chemicals resistance and high strength, it can be aged under service conditions such as high temperature, ultraviolet (UV) light, and chemicals exposure. These conditions accelerate oxidation of geomembrane and lead to brittle behavior and stress cracking which reduce its service life.

Our objective in this …

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 …

Experimental Investigations Of Levee Breach Flows, Ibrahim Adil Ibrahim

Theses and Dissertations

Two individual but related problems involving levee breach flow are studied. The first one involves experimental and dynamic modeling of steady flow through a levee breach, and the second one involves experimental investigation of flood management by an engineered levee breach. Both studies are conducted in the Hydraulics Laboratory, the University of South Carolina.

In the first problem, an idealized levee breach on a trapezoidal embankment was studied. Flow data including water depths, surface velocities, and flow discharges were collected from 28 experiments considering different cases of breach width and downstream water depth. Ultrasonic sensors were used to record the …

Laboratory Evaluation Of Cold In-Place Recycling Asphalt Mixtures Using A Balanced Mix Design, Ahmed Saidi

Theses and Dissertations

The objective of this research study is to present a procedure for designing Cold In-Place Recycling (CIR) mixtures through balancing cracking and rutting for these mixtures. Eight CIR mixtures were prepared using two recycling agents (foamed and emulsified asphalts), then cured for three days at two temperatures (140oF and 50oF), and compacted at two gyration levels (30 and 70 gyrations). The CIR mixtures were prepared at constant dosages of water and cement, 3% and 1%, respectively. Air void of each CIR performance test specimen was determined using the CoreLok device. The rutting susceptibility of these mixtures was then evaluated using …

Long-Term Performance Of Sustainable Pavements Using Ternary Blended Concrete With Recycled Aggregates, Seth M. Wagner

Theses and Dissertations

The purposes of this study were to (a) design concrete pavement mixtures with recycled concrete aggregates using ternary blends of cementitious materials and a low water-to-binder ratio, (b) measure the fresh and hardened properties of the proposed concrete mixtures and (c) assess the long-term performance of the concrete implementing the use of recycled coarse aggregates. Preliminary investigation into ternary blend combinations via the compressive testing of mortar cubes and isothermal calorimetry was used to predict an optimal blend of cementitious material. Mixes using recycled concrete aggregates at varying replacement rates were tested for fresh and hardened properties using the proposed …

Prototyping Elliptically Profiled Inverted Pendulum Walls In Cross-Laminated Timber (Clt) For Passive Self-Centering And Seismic Resiliency, Marco Lo Ricco

Theses and Dissertations

Cross-laminated timber (CLT) buildings garnered international attention, nearly a decade ago, for elevating wood construction to new heights on fully panelized assemblies of floors and walls. While highly regarded as a sustainable building material, use of CLT as a structural wall system depends on seismically resilient strategies like controlled rocking. This project prototyped elliptically profiled CLT panels and slotted-pin steel connections, at full-scale, to produce rolling and slip-friction inverted pendulum wall systems of one-story height and inspired by seismic isolation concepts. Digital fabrication realized elliptical profiles along the load-bearing edges of six 5-ply CLT panels and various customized slot shapes …

Energy Dissipating Connector For Precast Shear Walls In High-Seismic Areas, Mohammed Aljuboori

Theses and Dissertations

ABSTRACT

ENERGY DISSIPATING CONNECTOR FOR PRECAST SHEAR WALLS IN HIGH-SEISMIC AREAS

By

Mohammed Aljuboori

The University of Wisconsin – Milwaukee, 2019

Under the Supervision of Dr. Habib Tabatabai

Precast concrete systems are widely used in a variety of structures such as parking garages, residential units, shopping centers, and transportation stations. In some cases, precast structures are preferred over conventional cast-in-place (CIP) concrete conventional structures because of ease of construction, rapid implementation, and lower levels of energy consumption. One area where precast systems have traditionally been at a disadvantage is high seismic applications. In seismic regions, precast concrete structures must have …

Assessment Of Some Of The Common Practices Used In Scheduling Highway Projects, Jennifer Reyes

Theses and Dissertations

There are several factors documented in the literature that can affect the accuracy of estimated project durations in highway construction, such as weather, location, and soil conditions. Recently, the Texas Department of Transportation (TxDOT) raised a concern regarding some of the practices used when estimating the contract time for projects. This research presents an assessment of the effect that two practices identified have on the estimated project duration. These two practices include: 1) the estimated lead/lag times in project schedules and 2) scheduling with only critical or controlling activities. The effect of these practices is measured, primarily, by using four …

Construction Of Bismuth Oxyhallide-Based Heterojunction-Structured Composite And Its Environmental Application For Water Treatment, Li Wang

Theses and Dissertations

With the rapid development of the global economy, environmental protection and sustainable development have become the main trends of current society. In particular, water pollution and energy shortage are outstanding issues that need to be solved in a clean and sustainable way. Recently, semiconductor-based photocatalytic technology, an environmentally friendly technique, has attracted enormous attention and become an emerging research hotspot in the application of water/wastewater treatment and generation of renewable energy as it can convert infinite solar energy into chemical energy. Conventional semiconductor materials usually have a relatively large band gap that only responds to the ultraviolet light, which largely …

Study Of The Long-Term Shaft Resistance Of Energy Piles In Saturated Clays, Saeed Yazdani Kachooie

Theses and Dissertations

This research aims to qualitatively/quantitively assess the effect of temperature variation on the energy pile shaft resistance. The important mechanisms by which heating can change the shear strength of clay and clay-concrete interface are evaluated using experimental and numerical methods. As for experimental method, temperature-controlled triaxial tests, constant normal load (CNL) direct shear tests and small-scale pile tests were conducted. As for numerical approach, a fully coupled thermo-hydro-mechanical (THM) analysis was performed to simulate the experimental test results so that the capability of such analysis to predict thermo-mechanical behavior of energy piles is evaluated. Reconstituted (HC-77) kaolin clay, one-dimensionally consolidated …

Evaluation Of The Cracking Performance Of Geogrid-Reinforced Hot-Mix Asphalt For Airfield Applications, Daniel Offenbacker

Theses and Dissertations

The objective of this study was to evaluate the fatigue cracking performance of geogrid-reinforced Hot-Mix Asphalt (HMA) for use in airfield runways. An airfield HMA mixture with four different geogrid types were selected for this study. The geogrids varied in tensile strength, coating type, opening size, thickness, and fiber material. Several different laboratory performance tests were conducted (Dynamic Complex Modulus, DCM, Overlay Test, OT, and Indirect Tensile Strength, ITS) and the fatigue and/or cracking performance was evaluated. Additionally, different approaches were adopted or developed for the modeling of geogrids in HMA using Finite Element Modeling (FEM). Finally, a Life-Cycle Cost …

Modeling To Predict The Salt Transport Between A Scale Model Estuary And The Unconfined Aquifer With Groundwater Flow, Abeer Ibraheem Khazaly

Theses and Dissertations

In many field studies, variation in fluid density may have important effects on controlling groundwater flow and solute transport processes. These studies include: Indian River Lagoon (IRL), a coastal estuary, located on the east coast of Florida, saline disposal basins, radioactive waste disposal and contaminant spills. In the environment, where the fresh groundwater region is in direct contact with the saline seawater region in coastal aquifers, dynamic equilibrium normally exists between these two regions, but there are numerous human and environmental factors that can adversely impact the equilibrium and lead to severe saltwater contamination of the freshwater region. Intrusion of …

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 …

Damage Evaluation Of Concrete Structures Using Acoustic Emission, Rafal Anay

Theses and Dissertations

The deterioration and aging of the infrastructure in the U.S. have become a crucial issue, especially for highway bridges and nuclear power plants. The reliability and safety of existing structures are affected by growing populations and limited resources. This issue has gained significant concern during the last two decades and efforts are being conducted to accelerate the improvement of nondestructive testing (NDT) and structural health monitoring (SHM) methods. Additional information regarding the condition of existing structures and the early detection of damage can aid in reducing overall maintenance costs. The studies presented in this dissertation employ acoustic emission (AE) as …

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 …

Health Monitoring Of Liquid Pipelines, Mohammed Hameed Sabhan Al-Tofan

Theses and Dissertations

The crude and refined oil, water, and other liquids are widely transported through pipelines over long distances within geographical boundaries of countries or beyond. Pipeline accidents, however, are frequent, affecting operation and reducing targeted performance. The frequency of these accidents presents a growing concern and necessitates the need for an effective health monitoring plan. This plan requires monitoring of flow conditions and warning of any changes or abnormal conditions. Abnormalities in the flow conditions include changes in the piping system performance due to defects, such as leaks and blockages. These changes can be located and quantified utilizing different approaches. Two …

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 …

Development Of A Simplified Performance-Based Procedure For Assessment Of Post-Liquefaction Settlement Using The Cone Penetration Test, Jingwen He

Theses and Dissertations

Earthquake-induced liquefaction can cause severe damage to infrastructure is a serious concern in civil engineering practice. Post-liquefaction settlement is one of the common effects of liquefaction. The ability to predict and quantify post-liquefaction free-field settlement is a crucial part of seismic design. Many approaches have been developed during the past 50 years to perform liquefaction hazard analysis. The performance-based earthquake engineering (PBEE) framework developed by the Pacific Earthquake Engineering Research (PEER) center is a probabilistic framework that can provide a more accurate and complete seismic hazard analysis than other traditional methods. However, the PBEE framework is not widely used in …

Management Of Global Reservoir Sedimentation: Evaluating Rescon 2 For Sediment Management Alternatives, Christopher Jacob Garcia

Theses and Dissertations

Reservoir sedimentation occurs as dams impound streams and rivers, preventing the delivery of sediments downstream. Globally, reservoirs lose approximately 40 million acre-ft of storage to sediments each year. Several methods for managing reservoir sedimentation have been developed to help extend project life. In 2017, the World Bank sponsored REServoir CONservation (RESCON) 2, a pre-feasibility program aimed to help users select sediment management practices to consider for more detailed studies.There are two main objectives to this research: 1) perform a sensitivity analysis to understand which parameters require greater precision and which can be roughly approximated, and 2) evaluate RESCON 2 suggested …

Structural Health Monitoring Of Laminate Structures Using Shear-Mode Piezoelectric Sensors, Hussain Altammar

Theses and Dissertations

Structural health monitoring (SHM) employing embedded piezoelectric transducers has shown potential as a promising solution for inspection of different engineering structures such as aircraft, bridges, and renewable energy structures. Despite advancements in the field of ultrasonic SHM, inspection of laminate structures is still a major challenge due to their susceptibility to various joint defects. This thesis presents a novel approach to tackle the challenge of inspecting laminate structures using shear-mode (d35) piezoelectric transducers that are made of lead zirconate titanate (PZT).

This study begins with the characterization of d35 piezoelectric transducers using analytical, numerical, and experimental approaches. The results were …

Analysis Of Frp-Wrapped Concrete Piles In Integral Abutment Bridges Subjected To Axial And Cyclic Lateral Loads, Hassan Mohammed Magbool

Theses and Dissertations

ABSTRACT

The long-term maintenance problems associated with expansion joints, which are used to accommodate bridge movements in conventional bridges, have been the primary motivation for the use of integral abutment (jointless) bridges. These bridges rely on the interaction between the structure and the surrounding soil to accommodate bridge movements without the use of any expansion joints on the bridge superstructure. As the bridge superstructure expands and contracts due to seasonal thermal and other strains, relatively large forces can develop in the pile near the pile-cap interface. These reversible moment and shear forces can lead to localized damage near the top …