Engineering Commons^™

A System-Of-Systems Model To Simulate The Complex Emergent Behavior Of Vehicle Traffic On An Urban Transportation Infrastructure Network, Rayan Assaad, Cihan H. Dagli, Islam H. El-Adaway

Engineering Management and Systems Engineering Faculty Research & Creative Works

Transportation agencies face escalating challenges in forecasting the traffic demand. Traditional prediction methods focused on individual transportation sectors and failed to study the inter-dependencies between the different transportation systems. Hence, there is a need for more advanced and holistic modeling techniques. To this end, this paper models and analyses an urban transportation system-of-systems incorporating seven various systems: population and GDP, CO₂ emission, gasoline price and total vehicle trips, traffic demand, public and private transportation, transportation investment, and traffic congestion. Accordingly, this research simulates transportation networks as a collection of task-oriented systems that combine their resources to form a complex …

A System Dynamics Approach For Study Of Population Growth And The Residential Housing Market In The Us, Gasser Galal Ali, Islam H. El-Adaway, Cihan H. Dagli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The US Consensus bureau estimated the total construction spending at 1,320,305 Million Dollars, in February 2020, with an increase of 1.1% since last February. The construction market is large, and risky. Prediction of the market behavior, for several years ahead, is needed in order to take strategic investment decision for long and expensive projects. The goal of this research is to study the relationship between population growth and the housing market. To that end, a system dynamics model is developed. System dynamics is a top-down approach that starts with the high-level behavior of a complex system to simulate the behavior …

A System Dynamics Model For Construction Safety Behavior, Mohamad Abdul Nabi, Islam H. El-Adaway, Cihan H. Dagli

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Construction Industry has always been reputed by its high incident rates and poor safety performance. Construction accidents are, in most cases, resulted from the unsafe behaviors of construction workers on site. The study of workers' behavior is crucial in order to understand the causation of unsafe behaviors. Therefore, the objective of this paper is to simulate construction safety behavior in order to predict the number of safety incidents and better understand their causation factors. The simulation model illustrates how construction system influences construction labors on site in terms of unsafe behavior. The standard leading indicators of safety performance are first …

An Agent-Based Model To Study Competitive Construction Bidding And The Winner's Curse, Amr Elsayegh, Cihan H. Dagli, Islam H. El-Adaway

Engineering Management and Systems Engineering Faculty Research & Creative Works

Reverse auction theory is the basis for competitive construction bidding process. The lowest bid method is utilized for selecting contractors in public projects. The winning contractor having the lowest bid value could be cursed when the submitted bid value results in negative profits. This is caused by many factors such as the contractor's estimation accuracy and markup. This is addressed in this paper by providing a model simulating the construction competitive bidding and the occurrence of the winner's curse. To this end, the authors show the extent to which the winner's curse affects the status of contracting companies. The objectives …

Beaver Creek Restorative Design Using Engineering In Nature, Lindsay M. Levatino

Senior Honors Projects, 2020-current

Stream restoration work can be instrumental for the wellbeing of an ecosystem. Located in the Shenandoah Valley in Virginia is Beaver Creek, a well-known spot for fly-fishing due to its pristine water conditions and open surroundings. In order to maintain these conditions, a 100-foot stretch of Beaver Creek needed to be restored to prevent further erosion, stabilize the banks, and enhance the natural habitats. The project involved excavating a sediment island, filling in an eroded bank, building a cross vane, and adding stakes. Local stakeholders came together to complete this project contributing their expertise, equipment, and time. The construction was …

2-D Non-Linear Finite Element Analysis Of Folsom Dam: Seismically Induced Separation And Pore Pressure Along The Soil-Concrete Interface, Grace Amoussou

Master of Science in Civil Engineering Theses

The seismic soil-concrete interface stability of composite dams has been an area of interest to many researchers. However, the true interface behavior during a seismic event has not been well understood. During a ground shaking, bonding and de-bonding action along the interface may cause significant separation of soil and concrete surfaces, and such a separation may take place at any depth along the interface creating a stability concern for the overall dam. Moreover, the repetitive nature of bonding/debonding behavior may induce excess pore pressure along the interface, which in turn, may trigger a liquefaction failure or a hydraulic fracture in …

On The Seismic Performance Of Skewed Special Moment Frame Reduced Beam Section Connections, Damaso Daniel Dominguez

Graduate Theses and Dissertations

Special Moment Frames (SMFs) are frequently used in high seismic areas for architecturally constrained designs, as they provide lateral system stiffness without the use of braces which often obstruct views and architectural features. Reduced beam section (RBS) connections are popular SMF connection details developed following the Northridge earthquake to limit brittle fractures within connection welds. Current American Institute of Steel Construction (ASIC) provisions (i.e. AISC 341-16) provide prequalified SMF RBS connection details (including welding requirements); however, all prequalified details only consider orthogonal connections between the beam and column. This dissertation investigates the effect of adding skew within SMF RBS connections …

Development Of Vs Profiles And Site Periods In The Mexico City Basin, Landon Joel Woodfield

Graduate Theses and Dissertations

This study presents dynamic site characterization measurements at 25 sites within the Mexico City Basin. The primary focus of the testing was along the western edge of the Mexico City Basin. At each site, active source Multi-channel Analysis of Surface Waves (MASW) arrays and passive source Microtremor Array Measurements (MAM) L-arrays and circular arrays were used to acquire dispersion data. Horizontal to Vertical Spectral Ratio (HVSR) data was collected to determine site periods at each location. These experimental dispersion data and site periods were fit using a joint inversion of Rayleigh and Love wave dispersion data and HVSR site period …

Numerically Modeling Steel Continuous Bridges For Early Age Concrete Deck Cracking, Abdul Aziz Nabil Salah

Graduate Theses and Dissertations

Early age bridge deck cracking is a common problem throughout the United States. Early age cracking develops shortly after the deck is poured. It reduces the serviceability and lifespan of bridges. Early age cracking can be typically attributed to either of two factors, 1) construction practices, and 2) shrinkage. The Arkansas Department of Transportation (ARDOT) has experienced early age bridge deck cracking. ARDOT currently specifies a sequence deck pour on most of their bridges; however, contractors prefer continuous deck pours because of ease and construction time. During the period of this TRC1903 research project, ARDOT has only approved a few …

Numerical Simulations Of Spread Foundations Supported On Stone Columns Using The Discrete Element Method, Anibal Enrique Santos Marin

Graduate Theses and Dissertations

The implementation of stone columns as a ground improvement technique has become more popular in geotechnical construction practice as a result of their ability to improve strength, stiffness and permeability characteristics of weak clayey soil deposits. There are several analytical and empirical approaches to estimate the bearing capacity of stone column foundation systems; however, there is notable variation in the performance of these existing methods when compared with full-scale experimental results. For very weak cohesive soils (i.e., undrained shear strength less than 15 kPa), the use of conventional stone columns becomes restricted because of the insufficient confinement that these types …

Best Practices For Asphalt Emulsion Particle Size Analyses Using A Coulter Counter, Logan P. Kiihnl

Graduate Theses and Dissertations

As asphalt pavements develop distresses, pavement preservation, maintenance, and rehabilitation treatments are used to mitigate distresses and extend the life of the pavement. Many of these treatments utilize asphalt emulsion. Previous research has linked particle size to material properties including viscosity and storage stability. General statements have also been made about particle size influencing emulsion performance while other researchers have identified a trend between particle size and prime coat penetration. Even though literature discusses the importance of particle size, there is little guidance on the best practices of asphalt emulsion particle size analyses, specifically with a Coulter counter.

Data collected …

Development Of Multi-Axial Fatigue Retrofits For Lock Gate Components, Logan Verkamp

Graduate Theses and Dissertations

Lock gates are essential infrastructure components to the United State (US) supply chain. They create large cost savings and environmental benefits when compared with traditional methods of transport (freight and rail). Because of the large quantity of goods and dependence on these shipping chains, the US economy can be drastically affected by an unexpected gate closure. Unfortunately, many lock gates within the US have reached or exceeded their designed life. Due to the intensity of cyclic loads and the environment, fatigue cracks have become a prominent issue. Developed cracks near the pintle region (a joint which the gate rotates and …

Experimental And 3d Finite Element Analyses Of Invert-Removed Circular Corrugated Metal Pipe Culverts Renewed With Polymer Spray-Applied Pipe Lining, Samrat Raut

Civil Engineering Theses - Archive

Corrugated metal pipes (CMPs) are one of the widely used culvert structures in the American highway system. Compared to other types of culverts, CMPs have shorter design life, and many CMP culverts have reached or exceeded their design life. Therefore, renewal or replacement of those CMPs is needed to ensure the safety and service of the highways. Since replacements of these culverts are costly, renewalis less costly and has been on the focus in this decade. Different rehabilitation methods have been proposed by different DOTs and the researchers from open-cut methods to trenchless technology. Since open-cut methods disturb the operation …

Flexural Load Capacity Of Heat-Treated Concrete Mixed With Recycled Glass Aggregate And Glass Pozzolan, Enrique Gonzalez Tapia

Civil Engineering Theses - Archive

This research focuses on determining the effects of adding glass aggregate and glass pozzolan to concrete that has been exposed to high temperatures. Previous work, based on finding the recommended proportions of recycled components for optimum results, was done to analyze the effects of adding recycled glass components to concrete. Based on those studies, a replacement ratio of 30% glass aggregates and 20% glass pozzolan was used in this project. The compressive strength of concrete has been extensively studied and has been shown to increase in strength when glass components are used in their correct proportions. Less research has been …

Experimental Study Of Flexural Behavior Of Preflex Sfrc-Encased Steel Joist Composite Beams, Niraj Narendra Bankatlal Bora

Civil Engineering Theses - Archive

This study investigates the behavior of encased steel composite beams in straight and preflex beams, constructed and tested at Civil Engineering Laboratory Building (CELB). Upwards camber is provided in the steel sections in steel angles and HSS tube in the composite beam encased in Steel fibers reinforced concrete (SFRC). Experimental procedure has been performed to study the flexural behavior of composite steel joists encased in SFRC. Compressive strength, tensile strength and modulus of rupture are computed. The physical properties of steel fiber reinforced concrete are calculated through testing at the UTA Civil Engineering Laboratory Building. Eighteen cylindrical (4”x8”) specimens, eighteen …

Numerical Investigation Of Concrete Breakout Strength Of Anchors In Shear Within Fiber Reinforced Concrete, Yash Hitendrakumar Patel

Civil Engineering Theses - Archive

This study investigates the numerical analysis of concrete breakout strength of cast in place anchors in shear within synthetic fiber reinforced concrete (SYN-FRC). A three dimensional, full-scale model was developed using the ABAQUS 6.14 software. The 3D solid elements with consideration of material nonlinearities were chosen to stimulate the SYN-FRC beam anchorage. The numerical analysis was conducted with a fixed loading rate of 300lb per step to obtain the behavior of fiber-reinforced concrete breakout with design-mix compressive strength of 4,000 psi and fiber volume fraction of 0%, 0.5%, 1.0%, and 1.5%. An inverse analysis was used to calibrate the material …

Experimental And Numerical Study Of Steel Fiber Reinforced Concrete Structures Subjected To Internal Explosion, Nikhil Vasant Moon

Civil Engineering Theses - Archive

This research investigates the effect of an accidental explosion of a steam boiler in a boiler room on steel fiber reinforced concrete (SFRC) structure in an industrial facility, using nonlinear analysis in ABAQUS FEA software. The mechanical properties of SFRC are calculated through testing at the UTA Civil Engineering Laboratory Building. Steel fiber dosages in concrete at different volume fractions are examined for the mechanical properties of concrete. In total, 9 (4” x 8”) cylindrical specimens for compressive strength and modulus of elasticity test, 9 (4” x 8”) cylindrical specimens for tensile strength test, and 9 (6” x 6” x …

Riveted Steel Railway Bridge Health Monitoring And Damage Detection, Ahmed Rageh

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

Visual inspection is often used to assess the condition of railway bridges at discrete points in time, an approach that can be subjective and possibly unsafe. Alternatively, certain bridges have their condition assessed via the installation of a large number of sensors. These sensors can be costly to place, power and maintain. Therefore, reducing their numbers and maximizing the extracted information is of utmost importance. In addition, evaluating bridge condition from measured response can be quite challenging due to loading and environmental variations, especially when a limited number of sensors are used.

The focus of this research is to develop …

Promoting The Sustainable Utilization Of Groundwater Resources In Ethiopia Using The Integrated Groundwater Footprint Index, Xinyu Lin

Honors Scholar Theses

The country of Ethiopia is highly vulnerable to human-caused climate change and is already suffering from the effects. The predominately rural population relies heavily on small-scale agriculture, with 78% of households having at least one member engaged in the field, yet staple crops are highly susceptible to droughts and other weather shocks. Total and agricultural GDP growth in the country have been strongly linked to inter-annual rainfall variability, of which Ethiopia has among the highest in sub-Saharan Africa. A decrease in rainfall since the 1970s has been one of the primary causes of low crop yields, and stresses the immediate …

Examining Current State Of Practice Of Enhancing Visibility Of Winter Operations Vehicles, Wasiq Ameen

Civil Engineering Theses - Archive

Despite precautions taken by the operators of maintenance vehicles, insufficient visibility of winter operations vehicles cause many collisions in the United States. Numerous methods have been developed to enhance the visibility of winter operations vehicles. Although the visibility of winter operations vehicles has enhanced through these methods, the consistency in the implementation of the methods for enhancing their visibility is critical to avoid collisions. The inconsistencies in the implementation of the methods confuse the public who are traveling in winter conditions when visibility is low. The confusion leads to a delay in perception time and response time of the drivers …

Toward A Seismic Resistant Steel Staggered Truss Framing System (Stf), Ra'ed Al-Mazaidh

Civil Engineering Dissertations - Archive

The Staggered Truss Framing (STF) system is a type of steel structural system used in mid- to high-rise buildings. It was initially developed in the 1960s in order to create a steel framing system that has low floor-to-floor height (9 to 10 ft.) and wide column-free space (60 to 80 ft.). This system consists of a series of story-high trusses spanning the total width between two rows of exterior columns and arranged in a staggered pattern on adjacent column lines. Due to the staggered layout, lateral seismic force transfer in the STF system is also in a staggered manner from …

A Hybrid Experimental-Numerical Study On The Flow Topology In The Confluence Hydrodynamics Zone Of An Open Channel With Lateral Drainage Pipe Discharge, Mohammad Nazari-Sharabian

UNLV Theses, Dissertations, Professional Papers, and Capstones

To avoid disrupting the flow in flood control channels with lateral drainage pipes, or impact channel capacity, confluences are constructed at small angles (Maximum 30○). These small angles are costly to construct, since they require more real estate than greater angles.

By performing several laboratory experiments in the Fluid Dynamics Laboratory of the University of Nevada, Las Vegas (UNLV) and utilizing a numerical model (FLOW-3D), this study investigated the impact of submerged lateral drainage pipe discharges into rectangular open channels, on flow topology in the confluence hydrodynamics zone (CHZ). This was done across a range of channel widths, flow rates, …

An Evaluation Of Bank Storage At Lake Mead Reservoir In The Southwest United States, Jon Woodrow Wilson

UNLV Theses, Dissertations, Professional Papers, and Capstones

A water balance model is employed at Lake Mead to monitor and verify changing hydrology that affects total volume at the reservoir. Bank storage, which is defined as the volume of water captured in permeable lithologic layers subject to changes induced by contact and proximity to an open waterbody, is one component that is updated regularly and is based upon data and methods that were developed in the 1960’s from observations made within the first 30 years of the reservoir's maturation. Since this period, the reservoir has undergone further development and a current understanding of additional hydrologic affects to bank …

Bs News May/June

Building Services Engineering

No abstract provided.

Development Of Plane Rotating Traction System: Based On The High-Speed Rail (72+128+72) M Continuous Prestressed Concrete Beam Bridge, Weinan Wang

Theses and Dissertations

With the advent of rotate construction techniques, it is easy to build a new bridge crossing over existing structures, rivers and valleys quickly, easily and safely. Although the general concept of the rotating method is similar for different engineering characteristics, it is necessary to make some changes, which are more in line with the requirements of the particular project. Based on a 3-spans (72+128+72)m continuous concrete bridge, this paper presents a new rotation method, the down-slide-way unbalanced rotation system, which can save time and reduce cost compared to the up-slide-way rotation method. Through the improvements of the traction system and …

Designing Technology For Different Scales Of Irrigation Scheduling, Paolo Alexander Consalvo

Undergraduate Honors Capstone Projects

Uncertainty in water availability is a significant challenge to the agriculture industry. Farmers and irrigators depend on novel uses of sensors and data to maximize water efficiency. Documented studies have demonstrated scheduling irrigation is a straightforward, deterministic means of achieving water efficiency. Irrigation scheduling uses several parameters to determine the moment of crop water stress due to available water in the soil. However, sensors and data for soil moisture and matric potential, a parameter describing water available to plants, have the potential to train machine learning algorithms to forecast water irrigation needs based on previous measurements. Satellite remote-sensing is another …

Multiaxial Fatigue Of Notched Steel Plates And Investigation Of Cfrp Retrofits For Crack Initiation Prevention, Ayumi Fujii

Civil Engineering Undergraduate Honors Theses

Fatigue cracks are cracks that result from repeated loading over time, often following millions of loading cycles. Fatigue cracks occur even if the applied load is not large enough to cause material yield. Once a fatigue crack initiates, resulting stress concentrations at the crack tip often make it difficult to arrest the growth of the crack. In order to prevent growth and propagation of fatigue cracks within structural components, it is necessary to alter the stress condition at the crack tip. Fatigue cracks in steel structures resulting from multiaxial loading and or geometry conditions that result in complex states of …

Soil Moisture Content Determination By Means Of The Electromagnetic Spectrum, Julia Loshelder

Civil Engineering Undergraduate Honors Theses

Soil moisture content provides information about the strength, permeability, and compressibility of the soil under investigation. In the research described herein, the relationship between moisture content and reflectance values obtained from spectroscopy was developed to investigate whether in-situ moisture content can be determined in a faster and more efficient way than the current methods. The soil under investigation was laboratory-compacted kaolinite clay mixed with pyranine dye. These specimens were placed beneath an ultraviolet light and a halogen illuminator where reflectance values were collected over a 24-hour period. Correlations were developed from the following methods: 1) spectral indices, 2) continuum analyses …

Understanding Workability In Belitic Calcium Sulfoaluminate Concrete Mixtures, Caleb W. Chesnut

Civil Engineering Undergraduate Honors Theses

Belitic Calcium Sulfoaluminate cement (BCSA) is an emerging technology in the concrete industry. BCSA has similar hardened properties to portland cement (PC) but can set in under 20 minutes and reach 4,000 psi in less than 2 hours. Portland cement accounts for 8% of the world’s CO2 emissions, BCSA cements require less energy to produce. Studies have shown that 40% less CO2 is emitted during the production of BCSA cement than portland cement. This environmental benefit also makes it a very promising PC alternative. Before a new material can be used, designers need to understand the material’s properties. The goal …

Countermeasures For Pedestrian-Involved Accidents On Interstate-Highways, Anna C. Hunter

Civil Engineering Undergraduate Honors Theses

Pedestrian access to the Interstate is prohibited, but many pedestrian-involved accidents still occur on the Interstate in the United States. This project is a case study of West Memphis, Arkansas, which has the second highest occurrence of pedestrian-involved accidents on the Interstate in Arkansas. The study site location includes a segment of Interstate I-40 which is at- grade. The surrounding area contains several different land-uses, which is believed to be the primary generator of these accidents. The goal of this project is to determine the primary causes of these accidents and determine potential countermeasures to reduce the crash rate for …