Engineering Commons^™

High Strength Steel Fiber Reinforced Flow-Able Or Scc Concrete With Variable Fiber By Volume Fractions For Thin Plate And Shell Structures, Abebe Berhe

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to incorporate discrete, short, mechanically deformed, small diameter steel fibers into high strength concrete with f'c > 70 MPa (10 ksi) in an attempt to reduce and partially eliminate the need for steel rebar in concrete construction. By introducing steel fibers to high strength concrete mixture, the overall tensile, compressive and shear strength of the mixture can be improved immensely thus, replacing portions or major parts of the longitudinal, temperature and shrinkage reinforcements. The reduction or elimination of longitudinal and transverse reinforcements in the construction of structural or non-structural members can result in savings in …

Evaluation Of Phb Mid-Street Crossing System In Las Vegas, Nevada - Pedestrian Perspectives, Anna Eapen

UNLV Theses, Dissertations, Professional Papers, and Capstones

As the U.S. population ages and as more people choose to walk, it is critical to improve pedestrian safety. One of the best ways to encourage both pedestrians and vehicle drivers to behave safer is to make use of the most effective engineering traffic control systems. One such new technology is the Pedestrian Hybrid Beacon System (PHB), formerly known as the High-intensity Activated crosswalk (HAWK), a pedestrian-activated traffic-warning device. It features immediate activation of traffic warning lights from a dark state, a pedestrian countdown timer, and shorter pedestrian crossing times and traffic stoppage times compared to a traditional midblock traffic …

Gis-Based Route Risk Assessment Of Hazardous Material Transport, Myungwoo Lee

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

The transportation of hazardous materials keeps increasing across the United States due to the growing consumption of goods and rising need for manufactured materials. Furthermore, concerns are mounting over the safe surface transportation of hazardous materials. Highways and rails are the most common modes of transport for hazardous materials, although the risk posed from highway transport of hazardous materials may be higher due to the fact that highways are public while rails are mostly private. The majority of hazardous material cargo is carried on the highway network by trucks. Due to possible adverse effects on human and animal populations in …

Vulnerability Functions For Seismic Loss Assessment Of The Modern Multi-Story Buildings In Dubai, Abdul Rahman Abdul Aziz Ashri Hassan

Theses

The rapid developments in the United Arab Emirates along with the repeated seismic activity confirm the significance of planning for the possible damage that may hit earthquake-prone areas in order to mitigate earthquake losses. The contemporary buildings are the most important when estimating the potential losses from earthquakes since they represent concentrated economic and human assets. This study aims at developing vulnerability functions for a wide range of modern building inventory in a highly-populated and earthquake-prone area in the UAE. Ten reference buildings with varying heights from 2 to 100 stories and three different lateral force resisting systems are selected …

Developing A University-Wide Course On Sustainability: A Critical Evaluation Of Planning And Implementation, Can B. Aktas, Rosemary Whelan, Howard Stoffer, Edmund Todd, Cindy L. Kern Ph.D.

Civil Engineering Faculty Publications

Sustainability is an issue of increasing importance in today's world. Institutions of higher education are undergoing change towards incorporating sustainable development principles within their teaching, research, service, and community outreach efforts. This article presents a case study of the development and implementation of one such initiative: a university-wide freshman course centered on the topic of sustainability. The objective of the course was to expose freshman students to important sustainability issues in a common course team-taught by faculty from various disciplines. The article presents experiences and recommendations as a guide to administrators, faculty and researchers at other institutions of higher education …

Performance Evaluation And Integrated Management Of Airport Surface Operations, Qing Wang

USF Tampa Graduate Theses and Dissertations

The demand for aviation has been steadily growing over the past few decades and will keep increasing in the future. The anticipated growth of traffic demand will cause the current airspace system, one that is already burdened by heavy operations and inefficient usage, to become even more congested than its current state. Because busy airports in the United States (U.S.) are becoming "bottlenecks" of the National Airspace System (NAS), it is of great importance to discover the most efficient means of using existing facilities to improve airport operations.

This dissertation aims at designing an efficient airport surface operations management system …

Can Protected Bike Lanes Help Close The Gender Gap In Cycling? Lessons From Five Cities, Jennifer Dill, Tara Goddard, Christopher Monsere, Nathan Mcneil

Urban Studies and Planning Faculty Publications and Presentations

Even in areas with increased levels of bicycling, there remains a significant “gender gap” in bicycling in the United States, in contrast to many other countries with high rates of bicycling. The primary objective of this paper was to explore whether protected bike lanes could help reduce the gender gap. To do so, the authors used survey data from a comprehensive evaluation of protected bike lanes in five large U.S. cities (Austin, TX, Chicago, IL, Portland, OR, San Francisco, CA, and Washington, DC) that included survey responses of 1,111 intercepted bicyclists and 2,283 residents. Both men and women overwhelmingly felt …

Bs News November/December

Building Services Engineering

No abstract provided.

A New Decision Making Approach For Indirect Left Turn Treatments By Utilizing Decision Assistance Curves, Sunil Gyawali

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

This study developed decision assistance curves (DAC) for unconventional intersections, including median U-turns (MUT), continuous flow intersections (CFI), and jughandle intersections, based on their operational performance relative to a conventional intersection. An economic analysis was performed to compute the net present value (NPV) of benefits and the benefit to cost ratio (B/C) with the development of a spreadsheet tool. The DAC classified the region of optimal performance of isolated unconventional intersections. For 5% left turn traffic conditions, MUT was warranted for all volume criteria. For 10% and 15% left turn traffic conditions, jughandle was warranted for the major street approach …

Operation Optimization And Water Quality Simulation Of Potable Water Distribution System, Xiongfei Xie

USF Tampa Graduate Theses and Dissertations

A potable water distribution system (WDS) consists of pipes, pumps, valves, storage tanks, control and supporting components. Traditionally, it has two basic functions. First, provides end users with potable water at sufficient pressures and good water quality. Second, provides sufficient pressure and flow for fire fighting. Currently, potable water is still the least expensive material for fire fighting. To accomplish these two goals, water utilities have to consider the integrity and security of the water network. As a result, this research selected three research topics that are closely related to the daily operation of water utilities and water quality simulation. …

Field Cycle Length Sweep To Evaluate Resonant Cycle Sensitivity, Howell Li, Christopher M. Day, Alex M. Hainen, Amanda L. Stevens, Steven Lavrenz, W Benjamin Smith, Hayley Summers, Rick Freije, Jim Sturdevant, Darcy M. Bullock

JTRP Other Publications and Reports

Cycle length selection in corridor timing is often dictated by critical intersections with the highest level of saturation. Along corridors with balanced volumes and favorable link distances, a resonant cycle length is often sought to provide good progression in both directions of travel. This paper discusses the search for a resonant cycle length at a 5-intersection corridor in Fishers, Indiana over a three month period. The software traffic model suggests a reasonable range of cycle lengths from 104 seconds to 124 seconds for the corridor. This cycle length range is consistent with analytical highway capacity manual delay minimization approaches.

A …

Digitalcrust - A 4d Data System Of Material Properties For Transforming Research On Crustal Fluid Flow, Y. Fan, S. Richard, R. S. Bristol, S. E. Peters, S. E. Ingebritsen, N. Moosdorf, A. Packman, T. Gleeson, I. Zaslavsky, S. Peckham, L. Murdoch, M. Fienen, David G. Tarboton, N. Jones, Richard P. Hooper, J. Arrigo, D. Gochis, J. R. Olson, D. Wolock

Civil and Environmental Engineering Faculty Publications

Fluid circulation in the Earth's crust plays an essential role in surface, near surface, and deep crustal processes. Flow pathways are driven by hydraulic gradients but controlled by material permeability, which varies over many orders of magnitude and changes over time. Although millions of measurements of crustal properties have been made, including geophysical imaging and borehole tests, this vast amount of data and information has not been integrated into a comprehensive knowledge system. A community data infrastructure is needed to improve data access, enable large‐scale synthetic analyses, and support representations of the subsurface in Earth system models. Here, we describe …

Quantifying Economic Benefits For Rail Infrastructure Projects, Suzanna Long, Ruwen Qin, John Betak, Akhilesh Ojha, John J. Myers

Engineering Management and Systems Engineering Faculty Research & Creative Works

This project identifies metrics for measuring the benefit of rail infrastructure projects for key stakeholders. It is important that stakeholders with an interest in community economic development play an active role in the development of the rail network. Economic development activities in both rural and urban settings are essential if a nation is to realize growth and prosperity. Many communities have developed goals and visions to establish an economic development program, but they often fail to achieve their goals due to uncertainties during the project selection and planning process. Communities often select a project from a vast pool of ideas …

A Simple Formula To Calculate Azimuth Without A Two-Argument Arctangent Function, Thomas H. Meyer, Jacob Conshick

Department of Natural Resources and the Environment Articles

Calculating azimuths from planimetric coordinates is complicated when the available implementations of inverse trigonometric functions have ranges spanning only 180° instead of 360° as azimuth requires. A tangent half-angle formula is used to derive a formula with only one special case (due South) that computes azimuth for the whole circle.

Heavy Vehicle Rollover Propensity At Roundabouts On Highspeed Roads, Thomas M. Hall

Open Access Theses

There is a recent trend of building roundabouts on high-speed roads, often with significant heavy vehicle traffic. With the increased presence of trucks on roundabouts, the issue of rollover has become a concern. Geometric features that allow excessive speed on the approach and entry have been connected to rollover, as well as sudden changes in crossfall and radius. However, the effect on the rollover threshold of changing the roundabout's circulatory superelevation is not fully understood. The impact of aggressive driving behaviors, as displayed by high driver speed far from the roundabout, as well as errors that are manifested by the …

Water Resources Engineering 2: Water Resource Systems - George Mason University, Mark Houck

All ECSTATIC Materials

To introduce concepts, applications, and tools of systems analysis for water resources planning, management, and design.

To apply these principles to problems including river basin planning, real-time hydrosystem operations, water quality management, capacity expansion, urban drainage network design, and sanitary sewer design.

Course taught at George Mason University.

Computer Aided Water Management And Control - Colorado State University, John Labadie

All ECSTATIC Materials

Present modern computer-aided tools of systems analysis to planning, design, and operation of water resource systems. Topics covered include: optimal operation of multipurpose reservoir systems; optimal flood control system operations; coordinated unit commitment in hydropower systems; optimal multicrop allocation of seasonal and intraseasonal irrigation water; risk-based design of stochastic reservoir operating policies; economic evaluation of integrated design of water storage and conveyance systems; optimal conjunctive use of surface water and groundwater; optimal reservoir operations for water quality management; and optimal investment timing and selection of water resource projects. Several case studies are presented for river basins in the U.S., Dominican …

Environmental Systems Analysis - Penn State, University Park, Douglas A. Haith

All ECSTATIC Materials

Undergraduate course in environmental systems analysis offered at Penn State, University Park in Fall 2014.

Environmental Engineering Systems, Mark Houck

All ECSTATIC Materials

Introduces the concepts and applications of systems analysis in environmental engineering. Tools and methodologies of systems analysis are applied to improve the understanding and resolution of complex environmental engineering problems related to air, soil, and water quality and pollution. Scientific, engineering, political, social, legal, regulatory, medical, economic, and financial impacts of environmental engineering decisions are considered. Course taught at George Mason University.

Capacity-Related Driver Behavior On Modern Roundabouts Built On High-Speed Roads, Shaikh Ahmad

Open Access Theses

The objective of this thesis was to investigate the factors that affect capacity-related driver behavior on modern roundabouts built on high-speed roads. The capacity of roundabouts is strongly affected by the behavior of drivers as represented by critical headway (critical gap) and follow-up headway (follow-up time). The effects of heavy vehicles (single-unit truck, bus, and semi-trailer) and area type (rural or urban) on roundabout capacity were investigated by comparing the critical headways for roundabouts located on high-speed and low-speed roads. The effects of nighttime conditions (in the presence of street lighting) were also considered. Data were collected using the Purdue …

Strategies For The Replacement Of Historic Bridge Guardrails, Adam J. Clauss

Open Access Theses

Bridges that are designated historic present a special challenge to bridge engineers whenever rehabilitation work or improvements are made to the bridges. Federal and state laws protect historically significant bridges, and railings on these bridges can be subject to protection because of the role they play in aesthetics. Unfortunately, original railings on historic bridges do not typically meet current crash-test requirements and typically do not meet current standards for railing height and size of permitted openings. The objective of this study is to develop strategies that can be used to address existing railings on historic bridges and to develop solutions …

Fire Behavior Of Bolted Connections, Qiaqia Zhu

Open Access Theses

Bolted connection failures have been observed in building fires and large-scale structural fire tests. Limited information is available on plate bearing behavior at elevated temperatures. The failure mode of a shear-tab connection could change from plate bearing failure to bolt shear failure between 400 (degree Celsius) °C to 600°C. Component-based models have been used to predict the behavior of bolted connections. Earlier researchers have developed simple mathematical models to represent the force-displacement relationships of bolt shear and plate bearing components of bolted connections. However, these models need to be verified experimentally for US building construction and materials. Therefore, eleven single-bolted …

A Stochastic Multi-Criteria Assessment Of Security Of Transportation Assets, Michelle Sophie Dojutrek

Open Access Dissertations

Transportation project evaluation and prioritization use traditional performance measures including travel time, safety, user costs, economic efficiency, and environmental quality. The project impacts in terms of enhancing the infrastructure resilience or mitigating the consequences of infrastructure damage in the event of disaster occurrence are rarely considered in project evaluation. This dissertation presents a methodology to address this issue so that in evaluating and prioritizing investments, infrastructure with low security can receive the attention they deserve. Secondly, the methodology can be used for evaluating and prioritizing candidate investments dedicated specifically to security enhancement. In defining security as a function of threat …

Experimental Database, Analysis And Design Of Noncompact And Slender Concrete-Filled Steel Tube (Cft) Members, Zhichao Lai

Open Access Dissertations

Concrete-filled steel tube beam-columns are categorized as compact, noncompact or slender depending on the governing tube slenderness ratio. AISC 360-10 specifies the provisions for designing noncompact and slender rectangular and circular CFT members under axial compression, flexure, and combined axial and flexural loading. This research presents the development and evaluation of these design provisions. Available experimental databases of CFT members are reviewed, and a new experimental database of tests conducted on noncompact and slender CFT members is compiled. Detailed 3D finite element method (FEM) models are developed for noncompact and slender CFT members, and benchmarked using experimental results. The AISC …

Effects Of Web Reinforcement Discontinuities On The Seismic Response Of Structural Walls, Ying Wang

Open Access Dissertations

Field evidence was interpreted to suggest that discontinuities in the longitudinal web reinforcement caused severe damage in structural walls during strong ground motion. To test this hypothesis, six small-scale reinforced concrete structural walls were tested under lateral displacement reversals. Test variables included the presence of web longitudinal reinforcement discontinuities and number of loading cycles. The test results indicated that unit tensile strains in longitudinal reinforcing bars in boundary elements were approximately 50% higher in structural walls with web longitudinal reinforcement cutoffs relative to walls without reinforcement cutoffs. Higher unit tensile strains caused an increase in permanent strain accumulation, increasing the …

Nano-Modification For High Performance Cement Composites With Cellulose Nanocrystals And Carbon Nanotubes, Yizheng Cao

Open Access Dissertations

One of the new engineering frontiers is the exploration of infrastructure materials with novel combinations of properties that break traditional paradigms. The goal of this study is to utilize two different nano-fibers, cellulose nanocrystals (CNCs) and carbon nanotubes (CNTs) to modify the nanoscale structures of cement composites and thereby improve the performance at the macro-level. This study also evaluates the mechanism behind the modification, since fiber bridging, the most common reinforcing mechanism for fiber-reinforced composites, cannot be simply applied because CNCs are too short to bridge cracks in cement composites. ^ The mechanical tests show an increase in the flexural …

Impact Of Anthropogenic Activities On Hydro-Climatological Variables, Kuk Hyun Ahn

Open Access Dissertations

The natural environment has been significantly affected by anthropogenic activities. Between 1700s and 2000s, agricultural land area had quintupled and the extent of natural vegetation was globally reduced by half. Furthermore many scientists argue that the recent rise in CO2 levels in the atmosphere is mainly due to anthropogenic activities. Anthropogenic activities may also play a crucial role in the change of the hydro-climatologic variables. In this study, impact of anthropogenic activities on two representative hydro-climatologic variables, temperature and streamflow, is investigated. The variations in temperature occur over larger spatial and time scale, and hence the United States is adopted …

A Nonlinear Interface Formulation For Frictional Contact, Layla K Amaireh

Open Access Dissertations

Finite element simulations of contact problems often involve modeling the interaction of multiple bodies across a non-confirming interface. Non-Confirming Meshes (NCM) are typically associated with large sliding or adaptive refinement on one side of the interface to capture localized nonlinear behavior due to large deformations, damage and inelasticity. The use of NCMs, however, presents a number of numerical issues; the main challenge with such discretizations is to ensure compatibility of the kinematic and traction fields along the non-conforming interface. ^ The Enriched Discontinuous Galerkin Approach (EDGA) (Haikal and Hjelmstad,2010)addresses this challenge by implementing a local enrichment along with an interface …

Integrating Pro-Environmental Behavior With Transportation Network Modeling: User And System Level Strategies, Implementation, And Evaluation, Husain M. Abdul Aziz

Open Access Dissertations

Personal transport is a leading contributor to fossil fuel consumption and greenhouse (GHG) emissions in the U.S. The U.S. Energy Information Administration (EIA) reports that light-duty vehicles (LDV) are responsible for 61\% of all transportation related energy consumption in 2012, which is equivalent to 8.4 million barrels of oil (fossil fuel) per day. The carbon content in fossil fuels is the primary source of GHG emissions that links to the challenge associated with climate change. Evidently, it is high time to develop actionable and innovative strategies to reduce fuel consumption and GHG emissions from the road transportation networks. This dissertation …

Evaluation Of Collapse Indicators For Seismically Vulnerable Reinforced Concrete Buildings, Nicholas R. Skok

Open Access Theses

Older reinforced concrete buildings can be prone to column shear and compression failures during earthquakes because of inadequate transverse reinforcement. Cities in seismic areas still have large inventories of older and potentially deficient buildings. To analyze every building and estimate its vulnerability in detail is costly. A simple method to rank quickly older buildings according to their seismic vulnerability is needed to help engineers prioritize the use of resources for rehabilitating the most vulnerable buildings.

Four indicators of building damage or collapse were evaluated using numerical analysis and prior data from building surveys: column index (Hassan & Sozen, 1997), R …