Civil Engineering Commons^™

Cottonwood Riparian Site Selection On The Cheyenne River Sioux Reservation, Julie A. Thorstenson, Diane Rickerl, Janet H. Gritzner

Great Plains Research: A Journal of Natural and Social Sciences (through 2013)

The construction of the Oahe Dam on the Missouri River eliminated thousands of acres ofriparian and floodplain lands on the Cheyenne River Sioux Reservation in South Dakota. Restoration is needed to replace wildlife habitat. This study focused on site selection for native cottonwood (Populus deltoides Bartr. Ex Marsh. ssp. Monilifers (Ait.) Eckenwalde) restoration to help mitigate this loss. Geographic information systems technologies were used to develop a suitability model for cottonwood restoration. Tribal lands were extracted from a digital dataset oflandownership. Those touched by or included in a 46 m border of the Moreau River were candidate sites. Of …

Developing Deterioration Models For Nebraska Bridges, George Morcous Ph.D., Afshin Hatami Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

Nebraska Bridge Management System (NBMS) was developed in 1999 to assist in optimizing budget allocation for the maintenance, rehabilitation and replacement needs of highway bridges. This requires the prediction of bridge deterioration to calculate life-cycle costs. At the meantime, the approach adopted to predict the deterioration of bridge components is based on national average deterioration rates, which are one drop in the deck condition rating every eight years and one drop in the superstructure and substructure condition rating every ten years. This approach does not account for the impact of traffic volume, structure and material type, and environment impacts, in …

Crash Analysis Of I-64 Closure In St. Louis County, Ghulam H. Bham Ph.D., Uday R.R Manepalli

Mid-America Transportation Center: Final Reports and Technical Briefs

On January 2, 2008, the Missouri Department of Transportation (MoDOT) closed significant portions of Missouri Interstate 64 (I-64) in St. Louis County for reconstruction. During the planning stages of this project, the proposal to close all lanes of I-64 was met with public concern regarding the possible safety risks associated with diverting I-64 traffic to adjacent roadways. A specific concern was the possibility of increased crash rates on roads designated to receive I-64 traffic flow. The following research was conducted to assess the actual outcomes related to these concerns. Crash analyses and crash rate analysis of 2008 and 2009 crash …

Performance Measures Of Warm Asphalt Mixtures For Safe And Reliable Freight Transportation Phase Ii: Evaluation Of Friction And Raveling Characteristics Of Warm Mix Asphalt Mixtures With Anti-Stripping Agents, Hosin David Lee Ph.D., P.E., Yongjoo Thomas Kim Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

The viscosity of asphalt decreased significantly when 0.5% of WMA additive was added,but it remained relatively steady as the dosage rate increased up to 3.0%. The reduction pattern in viscosity as the dosage rate increases was similar for both CECABASE RT® and LEADCAP at all test temperatures of 120°C,125°C, 130°C and 135 °C and a similar pattern was observed for both Sasobit® and Rediset. Based on the ABCD test device, the virgin asphalt binder PG 64-34 cracked at -51.0°C and the PG 64-28 cracked at -41.3°C. As the WMA additives were increased from 0.5%to 3.0%, the cracking temperatures increased slightly,but …

Assessing The Damage Potential In Pretensioned Bridges Caused By Increased Truck Loads Due To Freight Moments (Phase Ii), Robert J. Peterman Ph.D., P.E., Steven F. Hammerschmidt M.S.C.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

With aging and deterioration of bridges, evaluation of existing conditions of their structural elements becomes vital to engineers and public officials when deciding how to repair or replace the structures. The ability to obtain necessary information on these conditions is often expensive and time consuming, especially for concrete bridges where the reinforcement is not available for inspection. Employing the surface-strain relief method could allow for accurate evaluation of aged or damaged prestressed members. The surface-strain relief method was developed to measure initial or pre-existing strains in a concrete member. It involves relieving the strain in the member and measuring the …

Effectiveness Study On Temporary Pavement Marking Removals Methods, Dr. Yong Cho, Dr. Jae-Ho Pyeon, Koudous Kabassi

Mid-America Transportation Center: Final Reports and Technical Briefs

This study was conducted to identify effective temporary marking removal methods and procedures on concrete and asphalt pavements. Pavement markings provide guidance to road travelers and can lead to accidents when not properly removed. Current state guidelines on removal do not provide clear and objective methods of measurement. After testing the most common removal methods, this research concluded that removing markings by chemical was not only cost efficient, result-oriented, and effective compared to other methods, but it was also safe to the environment and road users. Finally, a baseline of measurements was developed by the research team for this project, …

Investigating Rfid For Linear Asset Management, Judy A. Perkins Ph.D., P.E., Erick C. Jones Ph.D., P.E., Cssbb, Judith L. Mwakalonge Ph.D., E.I.T

Mid-America Transportation Center: Final Reports and Technical Briefs

A linear asset is defined as an asset whose length plays a critical role in its maintenance. Examples of such assets include roads, pipelines, and railroad tracks. Major features of a roadway asset include traffic lights, number of lanes, speed limits, guardrails, and highway billboards. Linear assets, along with their features, are hard to physically access; therefore, previously captured inventory information files may be inaccurate. To address this problem, some of the transportation agencies are investigating technologies that will assist in solving this asset inventory problem. Radio Frequency Identification (RFID) is a technology that uses communication via radio waves to …

Improving The Freight Transportation Roadway System During Snow Events: A Performance Evaluation Of Deicing Chemicals, Christopher Y. Tuan, Barbara M. Gerbino-Bevins

Mid-America Transportation Center: Final Reports and Technical Briefs

The ability of state DOTs to adequately clear roadways during winter weather conditions is critical for a safe and effective freight transportation system. Variables affecting winter maintenance operations include the type of precipitation, air and pavement temperature, traffic, wind, time of day, day of week, and maintenance equipment. The main objective of this study is to identify the best practices for normal deicing operations, based on the performance rating of deicing chemicals. Optimum deicer/brine ratios and the associated application rates will be determined for various weather conditions. The best practices will ensure effective deicing operation and economical use of deicing …

Impact Of Large 0.7 Inch Strand On Nu-I Girders, Maher K. Tadros Ph.D., P.E., George Morcous Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

The NU I-Girder series uses a unique cross-section and high-strength concrete to achieve longer spans. The objective of this project was to develop the quality control and design criteria required to introduce 0.7 inch strands at 2 in. spacing in NU I-Girders. Compared to 0.5 inch strands, only 1/2 of the total number of strands would be needed. This would result in immediate labor savings in precast concrete product costs. More importantly, having the ability to introduce almost twice the prestressing force, compared to 0.5 inch strands, and 135% of the prestressing force, compared to 0.6 inch strands, could result …

A Framework For The Nationwide Multimode Transportation Demand Analysis, Hojong Baik Ph.D., Yuepeng Cui, Tao Li

Mid-America Transportation Center: Final Reports and Technical Briefs

This study attempts to analyze the impact of traffic on the US highway system considering both passenger vehicles and trucks. For the analysis, a pseudo-dynamic traffic assignment model is proposed to estimate the time-dependent link flow from the intercity travelers on the network covering the continental U.S. A two-stage simulation scheme was designed to separate the intercity and non-intercity travelers involved in the link flow. The fuel consumption and emissions from the intercity travelers are estimated based on data in Mobile, the emission model developed by EPA. The suggested methodology could be adopted in further deployment of a nationwide transportation …

Modeling Truck Speed In The Upstream Of One-Lane Two-Way Highway Work Zones: Implications On Reducing Truck-Related Crashes In Work Zones, Yeu Li, Yong Bai Ph.D., P.E., Steven D. Schrock, Thomas E. Mulinazzi

Mid-America Transportation Center: Final Reports and Technical Briefs

Truck-related crashes constitute a major safety concern for government agencies, the construction industry, and the traveling public. Due to the rising needs in highway maintenance and construction, the number of work zones is increasing throughout the United States, while at the same time freight movement using trucks is also increasing nationwide. Developing effective safety countermeasures to reduce the truck-related crashes is a major challenge in front of the government agencies and the construction industry. The main objectives of this research project are to discover truck-related crash characteristics and to model the truck speeds in the upstream of one-lane two-way rural …

Impact Of Truck Loading On Design And Analysis Of Asphaltic Pavement Structures- Phase Ii, Yong-Rak Kim, Hoki Ban, Soohyok Im .

Mid-America Transportation Center: Final Reports and Technical Briefs

In this study, Schapery’s nonlinear viscoelastic constitutive model is implemented into the commercial finite element (FE) software ABAQUS via user defined subroutine (user material, or UMAT) to analyze asphalt pavement subjected to heavy truck loads. Then, extensive creep-recovery tests are conducted at various stress levels and at two temperatures (30oC and 40oC) to obtain the stress- and temperature-dependent viscoelastic material properties of hot mix asphalt (HMA) mixtures. With the viscoelastic material properties characterized and the UMAT code, a typical pavement structure subjected to repeated heavy truck loads is modeled with the consideration of the effect of material nonlinearity with a …

Evaluation Of Ndor’S Actuated Advance Warning Systems, Justice Appiah Ph.D., P.E., Laurence Rilett Ph.D., P.E., Zifeng Wu

Mid-America Transportation Center: Final Reports and Technical Briefs

Driver behavior within the dilemma zone can be a major safety concern at high-speed signalized intersections. The Nebraska Department of Roads (NDOR) has developed and implemented an actuated advance warning (AAW) dilemma zone protection system. Although these systems have received positive reviews from the public—and commercial vehicle operators in particular—there has been no comprehensive analysis of their effects on safety and traffic operations. The focus of this research was to conduct a quantitative study to ascertain the efficacy of the NDOR advance warning system. First, crash records from before and after the implementation of the system at 26 intersections were …

Model For Predicting The Impact Upon Economic Development Resulting From Highway Improvement Projects, Eric Thompson, Kanou Comlavi, Mallory Dimmit

Mid-America Transportation Center: Final Reports and Technical Briefs

The Nebraska Department of Roads (NDOR) has an interest in integrating state economic development impact as another factor in prioritizing transportation investments. Such efforts require the development of a comprehensive model that can be used to estimate a consistent final measure of economic development impact that can be readily integrated into existing prioritization formulas. This report summarizes the efforts of the University of Nebraska-Lincoln Bureau of Business Research (UNL-BBR) to develop such a model, by measuring the impact of expressway, viaduct, and other major investments projects around the state. Specifically, UNL-BBR developed an economic model to predict the economic impact …

Missouri Work Zone Capacity: Results Of Field Data Analysis, Ghulam Bham Ph.D., S. Hadi Khazraee

Mid-America Transportation Center: Final Reports and Technical Briefs

This report presents the results of work zone field data analyzed on interstate highways in Missouri to determine the mean breakdown and queue-discharge flow rates as measures of capacity. Several days of traffic data collected at a work zone near Pacific, Missouri with a speed limit of 50 mph were analyzed in both the eastbound and westbound directions. As a result, a total of eleven breakdown events were identified using average speed profiles. The traffic flows prior to and after the onset of congestion were studied. Breakdown flow rates ranged between 1194 to 1404 vphpl, with an average of 1295 …

Roadside Grading Guidance - Phase I, Kevin D. Schrum, Francisco D. B. Albuquerque, Dean L. Sicking, Ronald K. Faller, John D. Reid

Mid-America Transportation Center: Final Reports and Technical Briefs

Provisions for the design of roadside foreslopes are not readily available. As a result, engineering judgment is often employed. Unfortunately, this can lead to inconsistent designs, where, inevitably, some designs will be too costly and other designs will be too dangerous. Therefore guidance has been compiled to lend consistency to the design of these foreslopes while maintaining the most economical and safe design.

This guidance was prepared after conducting a benefit-cost analysis using the Roadside Safety Analysis Program (RSAP). A large test matrix was developed in an attempt to simulate the most possible scenarios, leaving interpolation to a minimum. However, …

Improving Safety And Mobility At High-Speed Intersections With Innovations In Sensor Technology, Anuj Sharma, Darcy M. Bullock, Senem Velipasalar, Mauricio Casares, Jacob Schmitz, Nathaniel P. Burnett

Department of Civil and Environmental Engineering: Faculty Publications

A series of innovations has been made in the vehicle sensors field. Technologies such as IntelliDrive and radar-based smart sensors make it pos­sible to track each vehicle in proximity to an intersection. However, current technologies have limitations, such as lack of robustness, accuracy, or level of penetration. This paper assumes an accurate wide-area detector (WAD), which might be soon available, and highlights the potential benefits that might be derived in safety and efficiency of oper­ations at high-speed intersections from the deployment of the WAD. Two critical areas in which wide-area detection can lead to significant improvements are discussed: (a) location …

Impact Of Signal Timing Information On Safety And Efficiency Of Signalized Intersections, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

Signalized intersections are provided in traffic networks to improve the safety and efficiency of vehicular and pedestrian movement. There are various measures under education, enforcement and engineering headings that are being attempted to improve safety and efficiency of operations at a signalized intersection. Provision of signal countdown timer, a timer showing the remaining red and green time in a phase, is one such measure and is commonly adopted in India. However, studies on effects of countdown timer under Indian traffic conditions are very scarce. Traffic heterogeneity and lack of lane discipline makes transferability of models developed in other countries (with …

Role Of Information On Probability Of Traffic Conflict On The Onset Of Yellow, Nathaniel P. Burnett, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

This paper examines the effect of information provided to drivers through advance warning flashers (AWFs) on driver’s probability of conflict at the onset of yellow at a high-speed intersection. AWFs are specifically designed to minimize the number of vehicles trapped in their respective dilemma zones at the onset of yellow. A probit modeling technique was used to establish dilemma zone boundaries. Based on the dilemma zone boundaries probability of a perceived conflict curves was computed and compared against actual conflicts observed at each of the studied intersections. The comparison between the actual and theoretical probability of conflict curves generated a …

Role Of Information On Probability Of Traffic Conflict On The Onset Of Yellow, Nathaniel P. Burnett, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

This paper examines the effect of information provided to drivers through advance warning flashers (AWFs) on driver’s probability of conflict at the onset of yellow at a high-speed intersection. AWFs are specifically designed to minimize the number of vehicles trapped in their respective dilemma zones at the onset of yellow. A probit modeling technique was used to establish dilemma zone boundaries. Based on the dilemma zone boundaries probability of a perceived conflict curves was computed and compared against actual conflicts observed at each of the studied intersections. The comparison between the actual and theoretical probability of conflict curves generated a …

Effects Of Warm-Mix Asphalt Additives On Asphalt Mixture Characteristics And Pavement Performance, Jun Zhang

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

The primary objective of this research is to evaluate the feasibility of several WMA mixtures as potential asphalt paving mixtures for Nebraska pavements. To that end, three well-known WMA additives (i.e., Sasobit, Evotherm, and Advera synthetic zeolite) were evaluated. For a more realistic evaluation of the WMA approaches, trial pavement sections of the WMA mixtures and their HMA counterparts were implemented in Antelope County, Nebraska. More than one ton of field-mixed loose mixtures were collected at the time of paving and were transported to the NDOR and UNL laboratories to conduct comprehensive laboratory evaluations and pavement performance predictions of the …

Soil Behavior Under Blast Loading, Jichong An

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

Understanding the behavior of soil under blast loading is very important to engineers in mining, tunneling, and military construction. Due to the very complex structure of a soil mass it is very difficult to describe its constitutive relation, especially when it has different water contents and it is under blast loading conditions. New protective system designs subjected to blast loading need to be proved its validation prior to predict effect of explosive before implementation. Full-scale, buried explosive tests are costly. Finite element simulations play a significant role in the design of protective systems, for example a bottom platform of lightweight …

A Generalized Non-Parametric Approach For Uncertainty Evaluation In Travel Time Prediction Models, Bhaven Naik

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

A core component within Advanced Traveler Information Systems is travel time information because it is easily understood and perceived by travelers. However, the suggested travel time information should be based not only on historical and real-time conditions, but also on forecasted or “unknown” future conditions.

Existing research has focused primarily on developing models that forecast point estimates of the mean travel time that are in close comparison to their respective field values. There has been limited research on any insight into the reliability or uncertainty margin that exists around the forecasted point estimate. As well, these researches have a limitation …

Embedded Radio Frequency Identification Device License Plates For Roadside Use In Nebraska, Dwight L. Mosby Jr.

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

The transportation industry has many stakeholders with different needs that work with advanced technologies. Radio Frequency Identification (RFID) is an emerging technology that is used to track inventory and it holds promise for the transportation industry. This research identifies how to evaluate transportation stakeholder requirements for RFID technologies using a tool described as the House of Quality (HOQ). This research investigates RFID’s ability to work in license plates and may provide infrastructure to support identifying RFID enabled commercial vehicles. This research considers variables that affect the performance of a RFID License Plate System that will use a scanner located at …

Changes In The Structure And Function Of Microbial Communities In Drinking Water Treatment Bioreactors Upon Addition Of Phosphorus, Xu Li, Giridhar Upadhyaya, Wangki Yuen, Jess Brown, Eberhard Morgenroth, Lutgarde Raskin

Department of Civil and Environmental Engineering: Faculty Publications

Phosphorus was added as a nutrient to bench-scale and pilot-scale biologically active carbon (BAC) reactors operated for perchlorate and nitrate removal from contaminated groundwater. The two bioreactors responded similarly to phosphorus addition in terms of microbial community function (i.e., reactor performance), while drastically different responses in microbial community structure were detected. Improvement in reactor performance with respect to perchlorate and nitrate removal started within a few days after phosphorus addition for both reactors. Microbial community structures were evaluated using molecular techniques targeting 16S rRNA genes. Clone library results showed that the relative abundance of perchlorate-reducing bacteria (PRB) Dechloromonas and Azospira …

Characterization And Pollutant Loading Estimation For Highway Runoff In Omaha, Nebraska, Camilo Torres

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

Stormwater from roadways could have negative effects on the environment. Typical highway runoff pollutants include heavy metals, petroleum hydrocarbons, gasoline constituents, PAHs (polyaromatic hydrocarbons), oxygen demanding compounds measured as COD (chemical oxygen demand) and BOD (biochemical oxygen demand), and road salts.

The objectives of this research were: characterize the pollutants in roadway runoff and determine the effectiveness of the existing stormwater BMPs at the study site. To accomplish these objectives, eleven rainfall events were sampled from November 2008 through November 2010.

First flush and composite highway runoff samples were analyzed for heavy metals, anions, nutrients, particulates, BOD, COD, VOCs, and …

Experimental Investigation Of Folded Plate Girders And Slab Joints Used In Modular Construction, Kyle A. Burner

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

The folded plate girder, a newly proposed bridge girder, is investigated through this thesis. The folded plate girder is cold bent out of a single sheet of steel. The cold bending eliminates the costly and inconsistent shop welds found in traditional girders. The folded plate girder is meant for application in short span bridges. The girder was subjected to an equivalent 75 year lifetime loading to investigate the fatigue performance.

The rebar detail used in the closure region between adjacent slabs has been investigated in the past by the NCHRP 12-68 project. This thesis will proposes a hooked rebar detail …

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 …

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, …