Civil and Environmental Engineering Commons^™

Constructability Testing Of Folded Plate Girders, Luke A. Glaser

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

A new steel girder bridge system was developed at the University of Nebraska. The innovative girder design is a box girder folded from a single steel plate that has a trapezoid shape with an opening on the bottom. The girder has application in short span bridges and accelerated construction situations. The structural performance of the girder requires investigation in all stages of a bridge’s lifecycle. This thesis contains descriptions and results from the first two tests from a series of tests developed to evaluate this new girder shape. The objective of these two tests was to investigate the constructability of …

Bottom Flange Reinforcement In Nu I-Grinders, George Morcous, Kromel E. Hanna, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of A Low Cost, Energy-Absorbing Bridge Rail, Dean L. Sicking, Robert W. Bielenberg, Ronald K. Faller, Karla A. Lechtenberg, Scott K. Rosenbaugh, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of Advanced Finite Element Material Models For Cable Barrier Wire Rope, John D. Reid, Karla A. Lechtenberg, Cody S. Stolle

Nebraska Department of Transportation: Research Reports

An improved LS-DYNA model of ¾-in. (19-mm) diameter 3x7 wire rope commonly used in roadside cable guardrail installations has been developed. A Belytschko-Schwer beam element was selected along with material *MAT_166. Numerical noise was reduced using part stiffness damping with a coefficient of 2%, and frequency range damping with a coefficient of 12%. The optimum element length based on timestep, accuracy, and computational cost was determined to be between 0.4 and 0.8 in. (10-20 mm). Dynamic component tests were conducted on wire rope to determine material properties. These tests were simulated and the results compared to the physical tests. The …

A Needs Assessment Of Highway Stakeholders Of An At-Grade Highway–Railroad Intersection In Lincoln, Nebraska, Ryan Haas

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

The University of Nebraska-Lincoln has deployed a data collection test bed along a rail

corridor in the City of Lincoln. The test bed spans about 2.5 miles along the corridor

which parallels Cornhusker Highway, with the focus placed on the Adams Street

highway rail grade crossing (HRGC). The test bed currently has some data-collecting

capabilities, but the possibility exists that there is additional data that could be useful to

various users of the rail crossings.

To gauge these possible unmet data needs of highway stakeholders, a needs

assessment was carried out by the author. A comprehensive literature review was done …

Impact Of Bottom Flange Confinement Reinforcement On Performance Of Prestressed Concrete Bridge Girders, Quinton Patzlaff

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

For many years AASHTO provided no recommendation to state DOT’s on bottom flange confinement reinforcement for their bridge superstructures. The 1996 edition of AASHTO Standard Specification for Highway Bridges stated that nominal reinforcement be placed to enclose the prestressing steel from the end of the girder for at least a distance equal to the girder’s height. A few years later the 2004 AASHTO LRFD Bridge Design Specification changed the distance over which the confinement was to be distributed from 1.0h to 1.5h, and gave minimum requirements for the amount of steel to be used, No.3 bars, and their maximum spacing, …

Load Rating Of Complex Bridges, George Morcous, Kromel E. Hanna, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Design Aids Of Nu I-Grinder Bridges, Kromel Hanna, George Morcous, Maher K. Tadros

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development Of A Temporary Concrete Barrier To Permanent Concrete Median Barrier Approach Transition, Mitchell J. Wiebelhaus, Karla A. Lechtenberg, Ronald K. Faller, John R. Rohde, Ryan J. Terpsma, Robert W. Bielenberg, Dean L. Sicking, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Impact Of Preferential Flow Paths On Alluvial Groundwater Flow Patterns And Phosphorus Transport, Derek M. Heeren, Ronald B. Miller, Garey A. Fox, Daniel E. Storm, Aaron R. Mittelstet, Chad J. Penn

Department of Agricultural and Biological Systems Engineering: Faculty Publications

While surface runoff is considered to be the primary transport mechanism for phosphorus (P), subsurface transport through coarse subsoil to gravel bed streams may be significant and represent a source of P not alleviated by current conservation practices (e.g., riparian buffers). Previous research has documented P transport in a preferential flow path (PFP) identified as a buried gravel bar. It is hypothesized that PFPs, if connected to the soil surface, provide a rapid and efficient method of transporting P, and that these alluvial features are transient storage zones for nutrients, acting as a sink during high flow and a source …

Foundation Design For High Tension Cable Guardrails, John R. Rohde, Ryan J. Terpsma, Ling Zhu

Nebraska Department of Transportation: Research Reports

No abstract provided.

Offset Right-Turn Lanes For Improved Intersection Sight Distance, Karen Schurr, Timothy J. Foss Jr.

Nebraska Department of Transportation: Research Reports

No abstract provided.

Geophysical Mapping Of Preferential Flow Paths Across Multiple Floodplains, Ronald B. Miller, Derek M. Heeren, Garey A. Fox, Daniel E. Storm, Todd Halihan, Aaron R. Mittelstet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In the Ozark ecoregion of Oklahoma, Arkansas and Missouri, the erosion of carbonate bedrock (primarily limestone) by slightly acidic water has left a residuum of chert gravel, producing gravel-bed streams and floodplains generally consisting of coarse chert gravel overlain by a mantle (1 to 300 cm) of gravelly loam or silt loam. Previous research has documented the occurrence of preferential flow paths (PFP) in an alluvial floodplain hypothesized to be a buried gravel bar. Field experiments have shown that the PFP affected alluvial groundwater flow in the floodplain and that water flow in the PFP was transmitted at rates that …

Safety And Driver Behavior Studies At Multiple Lane Approaches To Stop-Controlled Intersections, Karen Schurr, Daniel Sitorius

Nebraska Department of Transportation: Research Reports

Multiple-lane approaches (MLAs) controlled by stop signs are becoming increasingly common in Nebraska. Installation of MLAs occurs when a single approach lane can no longer adequately serve the minor road traffic volume, and a signal is unwarranted because Manual of Uniform Traffic Control Devices (MUTCD) warrants are not satisfied (7, FHWA, 2003). A common example of a location at which MLA stop-controlled intersections can occur in Nebraska is the rural intersection of two state or federal highways. Forty such intersections in Nebraska were available for study in this research. Additionally, such intersections are often located in suburban areas of Nebraska …

Affordable Lightweight High Performance Concrete (Alwhpc): Expanding The Envelope Of Concrete Mix Design, Kevin J. Simons

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

One way to reduce excess material would be to lighten the load on a structure with the use of affordable lightweight high performance concrete (ALWHPC). Most or all lightweight high performance concrete mixes used today include lightweight aggregates as the coarse aggregate and sand for the fine aggregate. ALWHPC mix designs contain all lightweight aggregates and cementitious materials that are readily available throughout the United States. Instead of 115 – 120 pcf, ALWHPC mix designs range from 88 – 100 pcf and strengths from 2,700 – 8,700 psi compressive strength. This research will explore the use of local lightweight aggregates …

Optimization And Economic Evaluation Of Industrial Gas Production And Combined Heat And Power Generation From Gasification Of Corn Stover And Distillers Grains, Ajay Kumar, Yaşar Demirel, David D. Jones, Milford Hanna

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Thermochemical gasification is one of the most promising technologies for converting biomass into power, fuels and chemicals. The objectives of this study were to maximize the net energy efficiency for biomass gasification, and to estimate the cost of producing industrial gas and combined heat and power (CHP) at a feedrate of 2,000 kg/h. Aspen Plusbased model for gasification was combined with a CHP generation model, and optimized using corn stover and dried distillers grains with solubles (DDGS) as the biomass feedstocks. The cold gas efficiencies for gas production were 57% and 52%, respectively, for corn stover and DDGS. The selling …

Time-Dependent Scour Depth Under Bridge-Submerged Flow, Yuan Zhai

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

Failure of bridges due to local scour has motivated many investigators to explore the reasons of scouring and to give the prediction of the scour depth. But most scour prediction equations only address non-pressure-flow situations. Little research has been dedicated to another destructive scour, submerged-flow bridge scour (pressure flow scour) which can cause significant damages to bridges when partially or totally submerged during a large flood.

This thesis is specifically focused on the experimental study for time-dependent scour depth under bridge-submerged flow. The experiments were conducted in a self contained re-circulating tilting flume where two uniform sediment sizes and one …

Use Of Passive Samplers To Evaluate Pharmaceutical Fate In Surface Waters, Delshawn L. Brown

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

Emerging contaminants have been of importance in recent water research. Wastewater treatment plants (WWTPs) have proved ineffective at handling present-day antibiotic loads from hospital and municipal sources. Kolpin et al. (2002) performed a study that identified pharmaceuticals in numerous waters downstream from effluent discharge. Though present in trace levels, concern has been raised regarding pharmaceutical persistence in natural environments. In the present study, uptake rates were quantified in the laboratory for 25 pharmaceutical compounds using Polar Organic Chemical Integrative Samplers (POCIS). Twenty new uptake rates were determined for compounds that have no previously reported literature values. POCIS was also used …

A Concise Model Of 3x7 Wire Rope Used In Cable Guardrail Systems, Cody S. Stolle

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Wire rope is a versatile, flexible, high-strength member that is used in many mechanical systems. However, due to the complexity of wire rope, analytical investigations have been relatively limited. Previous attempts to create simplified models of wire rope were not validated with physical testing and used a cumbersome beam-and-shell or beam-and-solid method for simulating the wire rope. An improved LS-DYNA model of 19-mm diameter 3x7 wire rope commonly used in roadside cable guardrail installations has been developed. A Belytschko-Schwer beam element was selected along with material *MAT_166. Since wire rope displays internal damping due to friction of strands and wires, …

Computational And Experimental Characterization Of Bituminous Composites Based On Experimentally Determined Properties Of Constituents, Pravat Karki

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

The stiffness of asphalt concrete mixtures is characterized in terms of the dynamic modulus for designing the thickness of flexible pavements. The dynamic modulus value of asphalt concrete is either determined experimentally or predicted by using empirical, semi-empirical, analytical or computational micromechanics models. This study proposes to use a computational micromechanics model to predict the dynamic modulus of asphalt concrete mixtures based on the experimentally determined properties of the constituents in the heterogeneous microstructure. The model defines asphalt concrete mixtures as the composites of two different homogeneous isotropic components – the viscoelastic fine aggregate matrix phase and the elastic aggregate …

Development And Evaluation Of The Midwest Guardrail System Placed Adjacent To A 2:1 Fill Slope, Mitchell J. Wiebelhaus, Ronald K. Faller, Robert W. Bielenberg, John R. Rohde, Karla A. Lechtenberg, Dean L. Sicking, Gopi Dey, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Development And Evaluation Of The Midwest Guardrail System (Mgs) Placed Adjacent To A 2:1 Fill Slope, Mitchell J. Wiebelhaus, Ronald K. Faller, Karla A. Lechtenberg, Dean L. Sicking, Robert W. Bielenberg, John R. Rohde, John D. Reid, Gopi Dey

Nebraska Department of Transportation: Research Reports

No abstract provided.

Cytotoxicity Of Bacterial-Derived Toxins To Immortal Lung Epithelial And Macrophage Cells, Dianne E. Peterson, Jayne M. Collier, Matthew E. Katterman, Rachel A. Turner, Mark R. Riley

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Health risks associated with inhalation and deposition of biological materials have been a topic of great concern due to highly publicized cases of inhalation anthrax, of new regulations on the release of particulate matter, and to increased concerns on the hazards of indoor air pollution. Here, we present an evaluation of the sensitivity of two immortal cell lines (A549, human lung carcinoma epithelia) and NR8383 (rat alveolar macrophages) to a variety of bacterial-derived inhalation hazards and simulants including etoposide, gliotoxin, streptolysin O, and warfarin. The cell response is evaluated through quantification of changes in mitochondrial succinate dehydrogenase activity, release of …

Development Of Advanced Finite Element Material Models For Cable Barrier Wire Rope, John D. Reid, Karla A. Lechtenberg, Cody S. Stolle

Mid-America Transportation Center: Final Reports and Technical Briefs

An improved LS-DYNA model of ¾-in. (19-mm) diameter 3x7 wire rope commonly used in roadside cable guardrail installations has been developed. A Belytschko-Schwer beam element was selected along with material *MAT_166. Numerical noise was reduced using part stiffness damping with a coefficient of 2%, and frequency range damping with a coefficient of 12%. The optimum element length based on timestep, accuracy, and computational cost was determined to be between 0.4 and 0.8 in. (10-20 mm). Dynamic component tests were conducted on wire rope to determine material properties. These tests were simulated and the results compared to the physical tests. The …

Second Generation Precast Deck Panel (Nudeck) System, Maher K. Tadros Ph.D., P.E., Kromel E Hanna, George Morcous Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

The majority of today’s bridge decks are built using cast-in-place concrete construction. This is due to the perceived low initial cost and constructor familiarity with the system. This research report describes the design, details, and construction of an innovative full-depth precast concrete bridge deck system – the Second Generation NUDECK (Nebraska University Deck). The quality of this system is far superior to castin- place construction. Cast-in-place concrete bridge decks experience cracking shortly after construction due to differential creep and shrinkage with the supporting beams. This leads to bridge deck deterioration; a problem that is not experienced with the virtually crack-free …

Safety Climate Of Commercial Vehicle Operation, Linda Ng Boyle Ph.D., Jeffrey Short

Mid-America Transportation Center: Final Reports and Technical Briefs

Enhancing the safety culture within trucking and motor coach industries has become a key area of concern given the potential impact it has on crashes and overall safety. Many organizations recognize that safety is compromised if the culture within their organization does not promote safety. Unfortunately, the specifics of a good safety culture and the methods by which safety culture is fostered are relatively ambiguous. A key reason for this is the general lack of standardization of the highly qualitative term ―safety climate‖ within the trucking and motor coach industries. A survey was completed by 31 organizations within these industries …

Developing A Sustainable Freight Transportation Framework With The Consideration Of Improving Safety And Minimizing Carbon Emissions, Margaret Rita Neff, Yong Bai, Steven Schrock, Thomas E. Mulinazzi

Mid-America Transportation Center: Final Reports and Technical Briefs

Despite the difficulties of the American economy in recent years the transportation sector continues to expand. Freight transportation alone has been projected to increase enormously even if the economy as a whole only manages a very moderate growth. Not only does freight transportation use a large percentage of resources but it contributes significantly to America’s share of carbon emissions and affects the safety of the transportation system and all its users. These problems are only expected to increase as the volume of freight transportation is already reaching the limit of the American transportation infrastructure’s capacity and demand continues to increase. …

Improving Freight Fire Safety: Analysis And Testing Of Real Engine Conditions To Progress Development Of Mist-Controlling Additives For Fire Mitigation, Albert Rathner Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

The formation of a fuel mist resulting from high shear stresses acting on the fuel during violent sloshing and tank rupture under the energy of a crash severely increases the occurrence and intensity of fires in transportation related accidents. In order to minimize such crash-induced fires, adding long chained polymers to diesel fuel was proposed to arrest the break-up of diesel into a fine mist. Such polymers with specifically engineered properties are intended to impart non-Newtonian characteristics to diesel, which would then alter its flow behavior under the applied shear stresses. As a first step in this direction, calculations are …

Mitigating Wind Induced Truck Crashes, Thomas E. Mulinazzi, Steven Schrock Ph.D., P.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

Dangerous weather and high wind in particular, is a common contributing factor in truck crashes. High wind speeds have been documented as a perennial cause of truck crashes in Kansas and other Great Plains states. The possibility of reducing such crashes, combined with the installation of dynamic message signs along Interstate 70, created an opportunity for further research. To this end, crash data were obtained from the Kansas Department of Transportation’s Accident Records System for all heavy vehicle crashes on I-70 that involved strong winds. The data were analyzed to determine the correlations between the vehicle and freight characteristics, crash …

Direct Detection Of Localized Modulation Of On Concentration On An Electrode-Electrolyte Interface, Ravi Saraf, Gaurav Singh

Mid-America Transportation Center: Final Reports and Technical Briefs

The present invention directly measures localized electrochemical processes on a planar electrode using differential interferometry. The ionic charge accumulation at the electrode-electrolyte interface may be directly measured by using differential interferometry as a function of magnitude and frequency (for example, 2-50 kHz) of an external potential applied on an electrode. Methods in accordance with the present invention probe the ion dynamics confined to the electrical double layer. An electric field is applied using a pure AC potential and a superposition of AC and DC-ramp potential to measure ion concentration and detect redox processes.