Engineering Commons^™

Automatic Object Recognition And Registration Of Dynamic Heavy Equipment Using A Hybrid Ladar System, Mengmeng Gai

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

It has been a challenging subject to recognize dynamic objects from a scattered work environment because large and complex 3D site data obtained by a laser scanner makes it difficult to process itself in real or near real time. This thesis introduces a model-based automatic object recognition and registration framework, Projection-Recognition-Projection (PRP), to assist heavy equipment operators in rapidly perceiving 3D working environment at dynamic construction sites. In this study, a digital camera and a hybrid laser scanner were used to rapidly recognize and register dynamic target objects in a 3D space by separating target object’s point cloud data from …

Dynamic Vulnerability Assessment Of Highway And Railway Bridges, Mehdi Mohseni

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

Dynamic loads can cause severe damage to bridges, and lead to malfunction of transportation networks. A comprehensive understanding of the nature of the dynamic loads and the structural response of bridges can prevent undesired failures while keeping the cost-safety balance. Dissimilar to the static behavior, the dynamic response of bridges depends on several structural parameters such as material properties, damping and mode shapes. Furthermore, dynamic load characteristics can significantly change the structural response. In most cases, complexity and involvement of numerous parameters require the designer to investigate the bridge response via a massive numerical study.

This dissertation targets three main …

In-Plane Shear Resistance Of Sustainable Structural Walls With Large Openings, Matija Radovic

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Shear walls are primary structural systems that support building against lateral loads (tornadoes and hurricanes). Even though concrete shear walls are the most efficient lateral resisting system, they are rarely used in a residential construction. The reasons for why contractors do not use concrete walls in residential construction were due to higher construction cost and slower construction paces. This study proposes building and testing residential concrete structural wall system that is energy efficient, cost competitive and structurally safe.

In order to decrease environmental impact of the residential construction process, this study proposed implementing sustainability concept while building residential structures. The …

Applications Of Cobb-Douglas Production Function In Construction Time-Cost Analysis, Ashkan Hassani

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

Cobb-Douglas Production Function was widely used in economics and productivity studies across many sectors. The function’s quantitative modeling of resource inputs and production outputs is appealing to the research domain of construction management. In this thesis we explored this function’s application in construction schedule crashing and project risk analysis related to duration of construction projects. Existing research on construction time-cost tradeoff issues rarely explore the origin of the crashing cost which is defined as the cost needed to shorten the project to the desired duration. In the existing literature crashing cost function was either assumed without much justification, or came …

Evaluation Of The Environmental Impacts Of Bridge Deck Runoff, Shannon L. Bartelt-Hunt, Lauren Swadener, Ekizabeth G. Jones

Nebraska Department of Transportation: Research Reports

Bridges are located in very close proximity to receiving waters, and regulatory agencies often require specific stormwater control measures for bridge deck runoff. While there is some information available on roadway runoff, few studies have focused on bridge deck runoff. Currently, there is no information available regarding the impacts of bridge deck runoff on receiving waters in Nebraska. Due to the cost, maintenance, and design issues associated with implementing structural controls for bridge deck runoff, it is important to develop a better understanding of the relationship between bridge deck runoff and potential impacts to receiving streams. The objectives of this …

Development And Evaluation Of Best Management Practices (Bmps) For Highway Runoff Pollution Control, Daniel Edward Jones

Department of Environmental Engineering: Theses and Student Research

As non-point source pollution, storm water runoff is one of the main contributors to stream impairment in the United States. The United States Environmental Protection Agency (USEPA) requires Municipal Separate Storm Sewer Systems (MS4s) to obtain a permit under the National Pollution Discharge Elimination System (NPDES) to manage this pollution. Many municipalities and non-traditional MS4s such as the Nebraska Department of Roads are under federal regulations that require new developments or redevelopments of a certain size to capture (and treat) runoff from all new impervious surfaces (roofs, driveways, sidewalks, and so forth) onsite, instead of allowing it to run into …

Video Detection Of Trains, Michael David Forsberg

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

This thesis discusses the use of video detection as a means for train detection. It reviews works done to increase safety at and near Highway-Rail Grade Crossings (HRGCs), discusses existing and past forms of technology and methods used in train detection and arrival time prediction, and provides summaries of investigations of other detection technologies used for vehicle detection. It then goes into depth on the use of radar and video detection with Autoscope Machine Vision Processing for train detection. This thesis provides a methodology of data collection, data analyses, results, and conclusions of video detection for train detection.

Data analyses …

Seepage And Stability Of A Dam In An Artesian Setting, Sean A. Parks

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

Willow Creek Dam is located in a unique region on the boundary of a confined aquifer, where artesian conditions exist. Recently, groundwater levels have exceeded the elevation of the downstream berm well above anticipated piezometric elevations. It was presumed from limited evidence that these high piezometric levels resulted from pressure in the aquifer rather than from seepage out of the reservoir. The purpose of this investigation was to determine the relative contributions of the reservoir and the regional groundwater to observed piezometric levels and how these levels affect seepage exit gradients and slope stability of the dam.

Comparing the head …

Characteristics Of Fatigued Commercial Motor Vehicle Drivers -- A Preliminary Investigation, Aemal Khattak, Carrie Mohlman

Nebraska Department of Transportation: Research Reports

The goal of this research was to identify and correlate easily observable characteristics of drivers to different levels of fatigue, thus enabling state patrol officers to make more judicious decisions related to driver fatigue. A literature review was conducted pertaining to the characteristics of fatigued drivers. Next, a nationwide survey was administered to state patrol agencies to assess their practices regarding fatigue-involved driving. To explore relationships between state patrol agency practices and vehicular safety, data collected from the telephone survey were merged with data from different states on fatigue-involved vehicle fatalities and vehicle miles traveled. Analysis revealed that states with …

Cable Median Barrier Failure Analysis And Prevention, Dean L. Sicking, Cody S. Stolle

Nebraska Department of Transportation: Research Reports

Cross-median crashes have been identified as one of the highest injury or fatality risk crash types. Although crossmedian crashes account for only 2% to 5% of all median crash events, they are disproportionately represented in the number and frequency of fatalities on interstate roadways. Many states have utilized cable median barriers to reduce the risk of cross-median crashes, frequently with great success. However, cable median barriers are also fixed obstacles to errant vehicles. Cable median barriers can place occupants at increased risk of severe injury or fatality if the barrier fails to adequately contain and redirect errant vehicles, resulting in …

Dynamic Testing Of Mgs W6x8.5 Posts At Decreased Embedment, Robert W. Bielenberg, Karla A. Lechtenberg, Ronald K. Faller, John D. Reid, Tyler L. Schmidt, Mario Mongiardini

Nebraska Department of Transportation: Research Reports

No abstract provided.

Determination Of The Maximum Mgs Mounting Height Phase Ii Detailed Analysis, Ramen D. Julin, Ronald K. Faller, John D. Reid, Mario Mongiardini

Nebraska Department of Transportation: Research Reports

No abstract provided.

Microbiologically Enhanced Mixing Across Scales During In-Situ Bioremediation Of Uranium, Reinaldo E. Alcalde

McNair Scholars Research Journal

Production of nuclear fuels for weapons and electric energy has resulted in groundwater uranium contamination at Department of Energy (DOE) sites. Reduction of uranium by dissimilatory metal-reducing bacteria (DMRB) is an effective approach for in-situ bioremediation of these sites. In this process, an organic electron donor is typically delivered through a well into groundwater in order to promote the biological reduction of soluble and toxic U(VI) to insoluble and less toxic U(IV). A key challenge is mixing the organic electron donor with U(VI) in groundwater where laminar flow conditions prevail. A potential solution is to enhance reaction beyond the scale …

Conductive Concrete For Electromagnetic Shielding – Methods For Development And Evaluation, Aaron P. Krause

Computer and Electronics Engineering: Dissertations, Theses, and Student Research

This research investigates the development and evaluation innovative methods for the use of conductive concrete as an electromagnetic shield. New testing methods are developed to determine the best conductive components to use in the design of a concrete mixture for shielding that shows the best promise. The conductive concrete mixture has the potential to provide electromagnetic shielding that is cost-effective in terms of construction, operation, and maintenance compared to conventional approaches. Two testing methods, Small Sample Testing and Large Slab Testing, are developed based on standardized testing methods that have been modified for the testing of conductive concrete mixtures. As …

Cable Median Barrier Failure Analysis And Remediation, Cody S. Stolle

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

On divided roadways, cross-median fatalities are disproportionately overrepresented in fatal and serious injury crashes. Many state DOTs sought to mitigate cross-median crash risk by installing cable median barriers. Despite increased crash rates, studies evaluating crash rates before and after cable median barriers were installed indicated excellent improvement in overall safety.

Although cable median barriers are intended to prevent serious cross-median crashes, cable barriers can also contribute to serious injury and fatality crashes which would not have otherwise occurred, including penetration and rollover crashes. In order to reduce the frequency of undesirable penetration and rollover crashes occurring with cable median barriers …

A New Approach To Safety Assessment At Gated Highway-Rail Grade Crossings, Zheng Luo

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

A significant number of pedestrians and bicyclists (i.e., non-motorists) use the roadway system in the U.S. Research pertaining to the safety of them, especially their safety at highway-rail grade crossings (HRGCs), has drawn much attention in the past decade, and remains an important issue of safety research. Yet, the majority of existing research has examined non-motorist safety at intersections or motorist safety at HRGCs separately. Such research has related primarily to exploring relationships between safety countermeasures (e.g., engineering devices, education, enforcement, etc.) and crash frequency/severity, using different quantitative analysis approaches. A primary limitation of these studies is that few have …

The Nebraska Water Leaders Academy: Blending Water Policy And Science With Leadership Theory, Mark E. Burbach, Connie I. Reimers-Hild

Nebraska Water Leaders Academy: Publications and Materials

Water Challenges are Growing
Population Continues to Grow
New and Innovative Leadership is Needed
Nebraska Water Leaders Academy (NWLA) was born!

NWLA Objectives
•Develop scientific, social and political knowledge about water and related natural resources
• Examine the economical and beneficial uses of Nebraska’s water resources
• Develop and enhance leadership and critical thinking skills
• Develop interpersonal skills to become actively involved with water policy issues at the local, regional, state, and national levels
• Develop life-long water resources management skills
• Challenge traditional paradigms while encouraging critical thinking and creative solutions.

Evaluation Of A Non-Proprietary, High-Tension, Four-Cable Median Barrier On Level Terrain, Karla A. Lechtenberg, Robert W. Bielenberg, Ronald K. Faller, Dean L. Sicking, Scott K. Rosenbaugh, Daniel M. Homan, Leah R. Kampschnieder, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Cost-Effective Treatment Of Existing Guardrail Systems, Mitchell J. Wiebelhaus

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

A cost-effective means for upgrading existing barrier systems, which have deviations from standard practice (i.e., low-rail heights, antiquated end treatments, and improper installation) does not exist. As a result these systems remain on U.S. highways. Barrier systems with deviations from current practice may not perform as intended, thus resulting in fatalities and serious injuries from impacts with these safety devices. It is not plausible to eliminate fatalities and serious injuries from all guardrail impacts; but these numbers could be significantly reduced with the proper design, testing, installation, and maintenance of guardrail systems.

This report offers recommendations for upgrading W-beam guardrails …

Transport Of Engineered Nanomaterials In Porous Media: Groundwater Remediation Application And Effects Of Particle Shape, Megan Seymour

Department of Environmental Engineering: Theses and Student Research

Nanotechnology, referring to any science which utilizes particles at the nanoscale, has substantially grown in recent years for its wide spectrum of potential uses. Many theories and models have been developed around the transport of spherical particles; however nanoparticles can be found in various shapes which could greatly affect the predicted transport and retention in the subsurface.

This research explores the beneficial use of carbon nano-onions (CNOs) for environmental remediation and investigates the transport of CNOs in saturated porous media. Surface oxidized CNOs possessed 10 times higher sorption capacity compared to C₆₀ for heavy metal ions including Pb^{2+ …}

Long-Term Trends In Air Temperature Distribution And Extremes, Growing Degree-Days, And Spring And Fall Frosts For Climate Impact Assessments On Agricultural Practices In Nebraska, Kari E. Skaggs, Suat Irmak

Department of Biological Systems Engineering: Papers and Publications

Air temperature influences agricultural practices and production outcomes, making detailed quantifications of temperature changes necessary for potential positive and negative effects on agricultural management practices to be exploited or mitigated. Temperature trends of long-term data for five agricultural locations, ranging from the subhumid eastern to the semiarid western parts of Nebraska, were studied to determine local temperature changes and their potential effects on agricultural practices. The study quantified trends in annual and monthly average maximum and minimum air temperature (T_max and T_min), daily temperature range (DTR), total growing degree-days, extreme temperatures, growing-season dates and lengths, and …

Using Slow-Release Permanganate Candles To Remove Tce From A Low Permeable Aquifer At A Former Landfill, Mark D. Christenson, Ann Kambhu, Steve D. Comfort

School of Natural Resources: Faculty Publications

Past disposal of industrial solvents into unregulated landfills is a significant source of groundwater contamination. In 2009, we began investigating a former unregulated landfill with known trichloroethene (TCE) contamination. Our objective was to pinpoint the location of the plume and treat the TCE using in situ chemical oxidation (ISCO). We accomplished this by using electrical resistivity imaging (ERI) to survey the landfill and map the subsurface lithology. We then used the ERI survey maps to guide direct push groundwater sampling. A TCE plume (100-600 µg L^-1) was identified in a low permeable silty-clay aquifer (K_h = 0.5 …

Characterization Of Runoff In Two Urban Watersheds In Lincoln, Nebraska, Michael J. Florek Iii

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

Characterization of runoff water quality and conditions for two urban watersheds in Lincoln, NE, was performed using data collected from 2008-2012. Water quality data from in-stream probes and storm sampling was combined with soil sample data, geographic information system (GIS) modeling, and nutrient isotope composition analysis to provide a more detailed picture of runoff mechanisms in the Taylor Park and Colonial Hills watersheds.

Soil sample data and GIS modeling were used to compare physical characteristics of the urban watersheds. Taylor Park and Colonial Hills are relatively similar, save for Colonial Hills being six times as large. Its time of concentration, …

An Analysis Of The Impacts Of Temperature Segregation On Hot Mix Asphalt, Thaddaeus A. Bode

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

This research was conducted to produce a more realistic picture of how variables are created and dealt with during hot mix asphalt (HMA) paving construction. Several paving projects across the State of Nebraska have been visited where sensing devices were used to test how the selected variables contribute to temperature differentials. These variables include density, moisture content within the asphalt, material surface temperature, internal temperature, wind speed, haul time, and equipment type. Areas of high temperature differentials are identified using an infrared camera whose usefulness was initially confirmed with a penetrating thermometer. A non-nuclear density device was also used to …

Cost-Effective Safety Treatments For Low-Volume Roads, Kevin D Schrum, Karla A. Lechtenberg, Cody S. Stolle, Ronald K. Faller, Dean L. Sicking

Nebraska Department of Transportation: Research Reports

No abstract provided.

Hydrologic Evaluation Of Established Rain Gardens In Lincoln, Nebraska, Andrew R. Anderson, Thomas G. Franti, David P. Shelton

Department of Biological Systems Engineering: Papers and Publications

Increased urbanization has resulted in water quality and flooding problems for many receiving waters in the United States. Rain gardens are one type of best management practice commonly used in low impact development (LID). Many studies have evaluated large engineered bioretention cells in research settings. There is little information on the effectiveness of homeowner-maintained rain gardens that rely on deep percolation as the method for water exfiltration. Repeatable controlled experiments are very rare in hydrologic studies due to the inherent variability of weather data. The objective of this study was to evaluate the hydrologic properties of twelve established rain gardens …

Efficient Prestressed Concrete-Steel Composite Girder For Medium-Span Bridges, Yaohua Deng

Department of Construction Engineering and Management: Dissertations, Theses, and Student Research

In this dissertation, a new Prestressed Concrete-Steel Composite (PCSC) girder system is introduced. The PCSC girder is composed of a lightweight W-shape steel section with shear studs on its top and bottom flanges to achieve composite action with the pretensioned concrete bottom flange and the cast-in-place concrete deck. The PCSC girder is lightweight, economical, durable and easy to fabricate. To prove its feasibility and potential, this study is to investigate design and fabrication issues associated with the PCSC girder. A service design procedure is proposed using Age-adjusted Elasticity Modulus Method (AEMM) to evaluate the time-dependent stresses and strains in the …

Test Matrices For Evaluating Cable Median Barriers Placed In V-Ditches, Ronald K. Faller, Scott K. Rosenbaugh, Mario Mongiardini, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of System Reliability Models For Railway Bridges, Anna Maria Rakoczy

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

Performance of the railway transportation network depends on the reliability of railway bridges, which can be affected by various forms of deterioration and extreme environmental conditions. More than half of the railway bridges in US were built before 1950 and many show signs of distress. There is a need for efficient methods to evaluate the safety reserve in the railway bridges by identification of the most sensitive parts of the bridge.

An accurate estimation of remaining fatigue life of a structural component is very important in prioritizing bridge rehabilitation and replacement. However, existing procedures to evaluate the fatigue behavior of …

Development And Recommendation For A Non-Proprietary, High-Tension, Cable End Terminal System, Ryan J. Terpsma, Ronald K. Faller, Dean L. Sicking, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.