Civil Engineering Commons^™

Evaluation Of J-Turn Intersection Design Performance In Missouri, Final Report, Praveen Edara Ph.D., P.E., Ptoe, Carlos Sun Ph.D., P.E., Jd, Sawyer Breslow

Mid-America Transportation Center: Final Reports and Technical Briefs

Research shows that a high percentage of crashes that take place on high-speed rural expressways occur at intersections with minor roads. One low-cost alternative design for improving the safety of at-grade intersections on such expressways is the J-turn. In the last few years, the Missouri Department of Transportation has converted some two-way stop controlled (TWSC) intersections into J-turns. This study evaluated the effectiveness of the J-turn intersection design in Missouri utilizing field studies, a public survey, crash analysis, and traffic conflict analysis. The field studies collected detailed video data at a J-turn site and a control site. The crash analysis …

Towards Autonomous Vehicles, Chris Schwarz Ph.D., Geb Thomas Ph.D., Kory Nelson B.S, Michael Mccrary B.S., Nicholas Schlarmann, Matthew Powell

Mid-America Transportation Center: Final Reports and Technical Briefs

We are moving towards an age of autonomous vehicles. Cycles of innovation initiated in the public and private sectors have led one into another since the 1990s; and out of these efforts have sprung a variety of Advanced Driver Assistance Systems and several functioning autonomous vehicles. The challenges that face autonomous vehicle are still significant. There is still technical work to be done to make sensors, algorithms, control schemes, and intelligence more effective and more reliable. As automation in vehicles increases, the associated human factors challenges become more complex. Then, there are a host of socioeconomic issues. Are autonomous vehicles …

Studying Platoon Dispersion Characteristics Under Heterogeneous Traffic In India, Jijo Mathew, Helen Thomas, Anuj Sharma, Lelitha Devi, Laurence Rilett

Department of Civil and Environmental Engineering: Faculty Publications

Platoons are created by signalized intersections which control travel patterns of vehicles. It is common for platoons to disperse during normal traffic operations. While platoon dispersion has been studied extensively under homogenous and lane disciplined traffic conditions, this characteristic under heterogeneous conditions has not been addressed adequately. This study will be one of the first steps in this direction and will lead to better understanding and simulation of platoon dispersion under Indian conditions.

Data describing platoon dispersion was collected with video recording systems along an arterial in Chennai, India. The Robertson’s model parameters calibrated for this data was found to …

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 …

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

Department of Computer Electronics and 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 …

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 …

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 …

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 …

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, …

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 …

Co-Removal Of Atrazine And Nitrate From Groundwater Using A Mulch Biofilm, Allison L. Cole

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

The popular broadleaf herbicide atrazine is often found in contaminated groundwater along with other agricultural chemicals, such as nitrate. Mulch biowalls, a passive treatment placed in situ, can inexpensively remediate groundwater by intercepting and treating a contaminant plume. Three types of organic mulch: cedar, cypress, and hardwood were evaluated for their ability to act as supporting materials for a biowall to simultaneously remove atrazine and nitrate from groundwater. Physical and chemical properties of the mulch were characterized. Cedar mulch had the highest organic carbon content, 996 mg/g. The adsorptive capacity of the mulch for atrazine and nitrate, in mono …

Prestressed Concrete Wind Turbine Supporting System, Ibrahim Lotfy

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

Wind energy is one of the most commercially developed and quickly evolving renewable energy technologies worldwide. Wind turbines are commonly supported on tubular steel towers. As the turbines are growing and the towers are elevating, an increase in structural strength and stiffness is required to withstand the applied forces. Recent studies established concrete as a more economic and durable alternative to steel especially when the tower height exceed 240ft. Presently, concrete towers are not common due to their perceived heavy weight and assembly complexity. One of the systems that have been mentioned in the literature consists of precast rings that …

An Evaluation Of Non-Intrusive Traffic Detectors At The Ntc/Ndor Detector Test Bed, Benjamin W. Grone

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

Throughout the field of transportation engineering, decision makers require quality information. The information used in transportation operations, planning, and design is based, in part, on data from traffic detectors. The need for quality data has spurred innovations in data collection including the introduction of modern, commercially available, non-intrusive traffic detectors. As these new technologies become available, a need exists to understand their capabilities and limitations—especially limitations that are unique to a specific region.

This thesis examined the accuracy of four non-intrusive traffic detector technologies considered for potential data collection applications on Nebraska’s highways. The technologies evaluated included the Solo Pro …

Safety Investigation And Guidance For Retrofitting Existing Approach Guardrail Transitions, Eric R. Jowza

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

Throughout the United States, various approach guardrail transition systems are routinely implemented by State Highway Departments to connect standard strong-post, W-beam guardrail systems to the blunt end of concrete bridge rails and roadside median barriers. When installed correctly, approach guardrail transitions shield the hazardous exposed ends of rigid parapets as well as significantly reduce the propensity for wheel snag and vehicle pocketing throughout the transition region. Unfortunately, approach guardrail transitions that are installed in the field may not always resemble that of the as-tested configuration, thus reducing the desired lateral stiffness and strength of the transition system. A recent survey …

Transversely Post-Tensioned Box-Beam System For Precast Parking Structures, Jenna Hansen

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

Parking structures are essential to any growing commercial district, yet little thought is given to their longevity and appearance. This is particularly the case with precast parking structures. Typical issues include poor joint performance and the impact of stemmed members on interior building aesthetics. Research provided in this report proposes an alternate design that improves long term joint performance and optimizes the perspective spacing between deck members. These benefits (along with the others) are incorporated to reflect the benefits of parking structures designed using cast-in-place concrete and structural steel with concrete decking. Other benefits include: flexible column spacing, reduced / …

Efficient Precast/Prestressed Floor System For Building Construction, Eliya E. A. Henin

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

Precast floor systems provide a rapidly constructed solution to multi-story buildings that is economical, high quality, fire-resistant, and with excellent deflection and vibration characteristics. Conventional precast concrete floor system cannot compete with cast-in-place post tensioning flat slab floor systems when high span-to-depth ratio and flat soffit are required. This is due to the significant depth of standard precast beams, and use of column corbels and beam ledges. This research presents the development of a new precast concrete floor system that eliminates the limitations of conventional precast floor system and provides a competitive precast alternative to cast-in-place flat slab floor systems. …

Characterization Of Viscoelastic And Fracture Properties Of Asphaltic Materials In Multiple Length Scales, Soohyok Im

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

Asphaltic materials are classical examples of multi-phase composites in different length scales. The understanding of the mechanical behavior of asphaltic materials has been a challenge to the pavement mechanics community due to multiple complexities involved: heterogeneity, anisotropy, nonlinear inelasticity, and damage in multiple forms. The micromechanics-based models based on numerical methods have been receiving attention from the pavement mechanics community because the modeling method can account for those complexities of asphaltic materials by considering the effects of material properties and geometric characteristics of individual components on overall performance behavior of mixture or structure. As a step-wise effort, this study intends …

Development And Recommendations For A Non-Proprietary, High-Tension, Cable End Terminal System, Ryan J. Terpsma

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

Cable guardrail systems have been increasing in popularity in recent years due to several perceived benefits over the commonly used W-beam guardrail. A non-proprietary design was desired as an alternative to the many proprietary designs available. A non-proprietary, high-tension cable end terminal was necessary to accompany the non-proprietary, high-tension cable guardrail system under development.

The objective of this research project was to develop design recommendations for a non-proprietary, high-tension cable end terminal. An analysis of several cable guardrail end terminals was undertaken to identify any common features that may prove to be beneficial or detrimental to end terminal designs. Next, …

Development Of Best Management Practice Design Guidance For Roadway Applications In Nebraska, Benedict Vacha

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

Runoff from roadways carries pollutants which may be detrimental to aquatic ecosystems. The primary pollutants of concern for roadway runoff are solids and heavy metals, particularly cadmium, copper, and zinc. Roadway runoff falls under the legislation of the Clean Water Act (CWA) via the National Pollutant Discharge Elimination System (NPDES). CWA regulates discharge of nonpoint source pollutants, such as roadway runoff, by issuing permits to public entities which manage Municipal Separate Storm Sewer Systems (MS4s). Part of the Nebraska Department of Roads (NDOR) permitting requirement is to create a design guide for Best Management Practices (BMPs) tailored to remediate roadway …

Impact Of Signal Timing Information On Safety And Efficiency Of Signalized Intersections, Anuj Sharma, Lelitha Vanajakshi, V. Girish, M. S. Harshitha

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 …

Development Of System Reliability Models For Railway Bridges, Andrzej S. Nowak Ph.D., Anna Maria Rakoczy Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

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 …

Effects Of Geometric Design Features On Truck Crashes On Limited-Access Highways, Sundanda Dissanayake Ph.D., P.E., Niranga Amarasingha M.S.

Mid-America Transportation Center: Final Reports and Technical Briefs

Freight can be transported between most points in the country quite efficiently using trucks. However, involvement of large trucks in crashes can cause much damage and serious injuries, due to their large sizes and heavy weights. Large truck crashes occurring on limited-access highways may be more severe than crashes occurring on other roadways due to high speed limits, and traffic- and geometric-related characteristics. The purpose of this study is to describe the relationships between large truck crash probability, and traffic and geometric characteristics. Crash data from 2005 to 2010 were obtained from the Kansas Department of Transportation (KDOT), which included …

Use Of High-Volume Reclaimed Asphalt Pavement (Rap) For Asphalt Pavement Rehabilitation Due To Increased Highway Truck Traffic From Freight Transportation, Mustaque Hossain, Haritha Y. Musty, Nasim Sabahfer

Mid-America Transportation Center: Final Reports and Technical Briefs

A recent rise in asphalt binder prices has led state agencies and contractors to use higher quantities of Reclaimed Asphalt Pavement (RAP). Besides being economic, sustainable, and environmentally friendly, RAP can be replaced for a portion of aggregates in Hot Mix Asphalt (HMA) where quality aggregates are scarce. In this project, the effect of increasing RAP percentage and using fractionated RAP (FRAP) in HMA mixture on moisture resistance, rutting, and fatigue cracking were evaluated. Mixtures with five different RAP and FRAP contents (20%, 30%, and 40% RAP, and 30% and 40% FRAP) were studied. The Hamburg Wheel Tracking Device (HWTD) …

Led Traffic Signal Replacement Schedules: Facilitating Smooth Freight Flows, Suzanna Long Ph.D., Ruwen Qin Ph.D., Abhijit Gosavi Ph.D., C. H. Wu Ph.D, Tom Ryan P.E., Casey Noll

Mid-America Transportation Center: Final Reports and Technical Briefs

This research details a field study of LED traffic signals in Missouri and develops a replacement schedule based on key findings. Rates of degradation were statistically analyzed using Analysis of Variance (ANOVA). Results of this research will provide a methodology for engineering managers in state departments of transportation and local communities in identifying best practices and replacement standards for LED traffic signal technology. These findings will facilitate smooth freight flows through the use of more efficient technologies

The U.S.-Canada Border Effect: Smaller Than Previously Thought And Becoming Smaller, Miwa Matsuo D.Des., Hirokazu Ishise Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

We revisit the effect of the U.S.-Canada national border on trade, considering to what extent the border reduces trade when observable economic factors are controlled. A reexamination of the data yields estimates of the border effect that are 50% higher than previously expected (Feenstra, 2004); however, the nonlinearity of the estimation and distance measure reduce the effect by 65%. We therefore conclude that the border effect in 1993 had a factor of 4.10. This figure is 15% lower than the effect proposed by previous research. We also calculate the border effect for subsequent years and find that this effect steadily …

Monitoring The Effects Of Knickpoint Erosion On Bridge Pier And Abutment Structural Damage Due To Scour, Thanos Papanicolaou Ph.D., David M. Admiraal, Christopher Wilson Ph.D., University Of Iowa

Mid-America Transportation Center: Final Reports and Technical Briefs

The goal of this study was to conduct a field-oriented evaluation, coupled with advanced laboratory techniques, of channel degradation in a stream of the Deep Loess Region of western Iowa, namely Mud Creek. The Midwestern United States is an ideal place for such a study considering that ~$1 Billion of infrastructure and farmland has been lost recently to channel degradation. A common form of channel degradation in this region is associated with the formation of knickpoints, which naturally manifest as short waterfalls within the channel that migrate upstream. As flow plunges over a knickpoint face, scouring of the downstream bed …

Feasibility Of Using Cellular Telephone Data To Determine The Truckshed Of Intermodal Facilities, Steven D. Schrock, Thomas Mulinazzi, Ming-Heng Wang

Mid-America Transportation Center: Final Reports and Technical Briefs

In order to determine the feasibility of using cellular telephone location data in deriving the geographic extent (truckshed) from intermodal facilities, this study was conducted to determine the feasibility analysis in three aspects: technology, penetration analysis and truck tracking methodology. A preliminary test was also conducted to demonstrate the cell phone tracking and traveling characteristics identification process using Washington, D.C. metropolitan area data provided by AirSage, Inc. The preliminary feasibility analysis found that cell phone locations could be located within an average of 100 meters or less of their actual position, which is feasible to use for a long haul …

Investigation Of Factors Associated With Truck Crash Severity In Nebraska, Aemal Khattak, Zheng Luo M.S, Mia Gao

Mid-America Transportation Center: Final Reports and Technical Briefs

The severity of truck crashes is a concern in the state of Nebraska. This study was undertaken to investigate factors associated with truck crash severity. A two-year dataset obtained from the Nebraska Department of Roads (NDOR) was analyzed to determine those factors. Results indicated that the involvement of alcohol was associated with more severe injuries in truck crashes on Nebraska highways. Crashes involving farm equipment were more injurious than other truck crashes. Dawn and dusk were critical periods associated with more severe truck crashes. Further, the absence of medians contributed to truck crash severity. Crashes on adverse pavement conditions such …

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

Mid-America Transportation Center: Final Reports and Technical Briefs

This study investigated the impact of the realistic constitutive material behavior of asphalt layer (both nonlinear inelastic and fracture) for the prediction of pavement performance. To this end, this study utilized a cohesive zone model to consider the fracture behavior of asphalt mixtures at an intermediate temperature condition. The semi-circular bend (SCB) fracture test was conducted to characterize the fracture properties of asphalt mixtures. Fracture properties were then used to simulate mechanical responses of pavement structures. In addition, Schapery’s nonlinear viscoelastic constitutive model was implemented into the commercial finite element software ABAQUS via a user defined subroutine (user material, or …