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Civil Engineering

University of Nebraska - Lincoln

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Full-Text Articles in Engineering

Determination Of Traffic Responsive Plan Selection Factors And Thresholds Using Artificial Neural Networks, Anuj Sharma Aug 2004

Determination Of Traffic Responsive Plan Selection Factors And Thresholds Using Artificial Neural Networks, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

Traffic congestion has become a menace to civilized society. It degrades air quality, jeopardizes safety and causes delay. Traffic congestion can be alleviated by providing an effective traffic control signal system. Closed-loop traffic control systems are an example of such a system.

Closed-loop traffic control systems can be operated primarily in either of two modes: Time of Day Mode (TOD) or Traffic Responsive Plan Selection Mode (TRPS). TRPS mode, if properly configured, can easily handle time independent variation in traffic volumes. It can also reduce the effect of timing plan aging. Despite these advantages, TRPS mode is not used as …


Least-Squares Finite-Element Lattice Boltzmann Method, Yusong Li, Eugene J. Leboeuf, P. K. Basu Jun 2004

Least-Squares Finite-Element Lattice Boltzmann Method, Yusong Li, Eugene J. Leboeuf, P. K. Basu

Department of Civil and Environmental Engineering: Faculty Publications

A new numerical model of the lattice Boltzmann method utilizing least-squares finite element in space and Crank-Nicolson method in time is presented. The new method is able to solve problem domains that contain complex or irregular geometric boundaries by using finite-element method’s geometric flexibility and numerical stability, while employing efficient and accurate least-squares optimization. For the pure advection equation on a uniform mesh, the proposed method provides for fourth-order accuracy in space and second-order accuracy in time, with unconditional stability in the time domain. Accurate numerical results are presented through two-dimensional incompressible Poiseuille flow and Couette flow.


Configuration Of Traffic-Responsive Plan Selection System Parameters And Thresholds: Robust Bayesian Approach, Montasir M. Abbas, Anuj Sharma Jan 2004

Configuration Of Traffic-Responsive Plan Selection System Parameters And Thresholds: Robust Bayesian Approach, Montasir M. Abbas, Anuj Sharma

Department of Civil and Environmental Engineering: Faculty Publications

Traffic-responsive plan selection (TRPS) is one of the two major closed-loop system modes of operation. The TRPS mode is more beneficial than its competitor (time-of-day mode) because of its ability to accommodate abnormal traffic conditions such as incidents, special events, and holiday traffic. However, no guidelines are available for optimal setup of TRPS systems. Improper configuration of a TRPS system can result in inefficient system performance or unstable operation in which the closed-loop system operates in a perpetual transitioning state. The TRPS mechanism implemented in current traffic signal controllers is described, and a Bayesian-based methodology for selecting an optimal set …


Development Of A Web-Based Mass Transfer Processes Laboratory: System Development And Implementation, Yusong Li, Eugene J. Leboef, P. K. Basu, Louis Hampton Turnver Iv Feb 2003

Development Of A Web-Based Mass Transfer Processes Laboratory: System Development And Implementation, Yusong Li, Eugene J. Leboef, P. K. Basu, Louis Hampton Turnver Iv

Department of Civil and Environmental Engineering: Faculty Publications

A web-based environment is utilized as a means to introduce advanced mass transfer processes concepts in environmental engineering and science courses. System development and implementation is presented, including detailed descriptions of the techniques employed to link software written in high level computer languages such as C++ and FORTRAN to an internet-based, user-friendly graphical user interface for both program input and output.


Safety Performance Evaluation Of Michigan’S 4x5 Portable Sign Support, Ronald K. Faller, James C. Holloway, John R. Rohde, Dean L. Sicking Jan 2003

Safety Performance Evaluation Of Michigan’S 4x5 Portable Sign Support, Ronald K. Faller, James C. Holloway, John R. Rohde, Dean L. Sicking

Mid-America Transportation Center: Final Reports and Technical Briefs

A wide variety of traffic controlling devices are used in work zones, some of which are not normally found on the roadside or in the traveled way outside of the work zones. These devices are used to enhance the safety of the work zones by controlling the traffic through these areas. Due to the placement of the traffic control devices, the devices themselves may be potentially hazardous to both workers and errant vehicles. The impact performance of many work-zone traffic control devices is mainly unknown and to date limited crash testing has been conducted, under the criteria of National Cooperative …


Performance Analysis Of Welch Products Recycled Rubber Spacer Block, Bob W. Bielenberg, Ronald K. Faller Jan 2003

Performance Analysis Of Welch Products Recycled Rubber Spacer Block, Bob W. Bielenberg, Ronald K. Faller

Mid-America Transportation Center: Final Reports and Technical Briefs

The Midwest Roadside Safety Facility was contracted by Will Stein of the Iowa Department of Transportation to conduct dynamic bogie testing of a recyclable rubber guardrail spacer block manufactured by Welch Products, Inc. The scope of the work included the setup of both a standard, wood guardrail post blockout and the Welch Products recycled rubber blockout on a standard W150x13.5 steel post, as well as two component tests using a bogie vehicle. The bogie tests were conducted in accordance with previously accepted procedures to evaluate the performance of guardrail post blockouts made of non-standard materials.


Guidelines For Attachments To Bridge Rails And Median Barriers, Eric A. Keller, Dean L. Sicking, Ronald K. Faller, Karla A. Polivka Jan 2003

Guidelines For Attachments To Bridge Rails And Median Barriers, Eric A. Keller, Dean L. Sicking, Ronald K. Faller, Karla A. Polivka

Mid-America Transportation Center: Final Reports and Technical Briefs

Highway agencies are often presented with the need to add attachments of various configurations to the top or backside of crashworthy traffic barriers. Although, the National Cooperative Highway Research Program (NCHRP) Report No. 350 offers guidance for the safety performance evaluation of traffic barriers, it offers no guidance toward the evaluation of attachments on or near these barriers. The objective of the research project was to collect crash test data relating to bridge rails and median barriers, to collect information about common attachments to traffic barriers, and to evaluate this information for the purpose of developing guidelines for the design …


Development Of A Low-Profile Bridge Rail For Test Level 2 Applications, Karla A. Polivka, Ronald K. Faller, Dean L. Sicking, John R. Rohde, John D. Reid, James C. Holloway Jan 2003

Development Of A Low-Profile Bridge Rail For Test Level 2 Applications, Karla A. Polivka, Ronald K. Faller, Dean L. Sicking, John R. Rohde, John D. Reid, James C. Holloway

Mid-America Transportation Center: Final Reports and Technical Briefs

A low-profile bridge rail was developed for installations where pedestrians and/or site restrictions prevent the use of conventional bridge rails with transitions. The bridge rail design was constructed using a 22.86-m long reinforced concrete parapet. The entire system measured 508-mm high by 356-mm and 279-mm wide at the top and bottom surfaces, respectively.

The research study included one full-scale vehicle crash test, using a 3⁄4-ton pickup truck. The full- scale test, impacting at a speed of 70.0 km/hr and an angle of 27.1 degrees, was conducted and reported in accordance with the requirements specified in National Cooperative Highway Research Program …


Development And Evaluation Of A Tie-Down System For The Redesigned F-Shape Concrete Temporary Barrier, Karla A. Polivka, Ronald K. Faller, John R. Rohde, James C. Holloway, Bob W. Bielenberg, Dean L. Sicking Jan 2003

Development And Evaluation Of A Tie-Down System For The Redesigned F-Shape Concrete Temporary Barrier, Karla A. Polivka, Ronald K. Faller, John R. Rohde, James C. Holloway, Bob W. Bielenberg, Dean L. Sicking

Mid-America Transportation Center: Final Reports and Technical Briefs

Often, temporary barriers are used in applications where it is desired that their deflection during vehicular impact be limited. One such application is in the installation of temporary barriers placed adjacent to the edge of a concrete bridge deck in order to maximize lane width. Acceptable tie-down systems for temporary barriers have previously been developed, but there are concerns when the barriers and tie-down systems are used on bridges that are reconstructed in stages and where very little tolerance in barrier deflection is allowable. Therefore, a rigid tie-down system was developed that minimizes barrier deflections. For this system, the original …


Effects Of Oxide Coating And Selected Cations On Nitrate Reduction By Iron Metal, Yong H. Huang, Tian Zhang, Patrick J. Shea, Steve D. Comfort Jan 2003

Effects Of Oxide Coating And Selected Cations On Nitrate Reduction By Iron Metal, Yong H. Huang, Tian Zhang, Patrick J. Shea, Steve D. Comfort

Department of Civil and Environmental Engineering: Faculty Publications

Under anoxic conditions, zerovalent iron (Fe0) reduces nitrate to and magnetite (Fe3O4) is produced at near-neutral pH. removal was most rapid at low pH (2–4); however, the formation of a black oxide film at pH 5 to 8 temporarily halted or slowed reaction unless the system was augmented with Fe2+, Cu2+, or Al3+. Bathing the corroding Fe0 in a Fe2+ solution greatly enhanced nitrate reduction at near-neutral pH and coincided with the formation of a black precipitate. X-ray diffractometry and scanning electron microscopy confirmed that both …


Development Of Standards For Placement Of Steel Guardrail Posts In Rock, Jason Herr, John R. Rohde, Dean L. Sicking, John D. Reid, Ronald K. Faller, James C. Holloway, Brian A. Coon, Karla A. Polivka Jan 2003

Development Of Standards For Placement Of Steel Guardrail Posts In Rock, Jason Herr, John R. Rohde, Dean L. Sicking, John D. Reid, Ronald K. Faller, James C. Holloway, Brian A. Coon, Karla A. Polivka

Mid-America Transportation Center: Final Reports and Technical Briefs

A steel post W-beam guardrail system was developed for installation in rock-soil foundations. The guardrail system was constructed with a 2.66-mm (12-gauge) thick W-beam rail, 53.34 m in length. The W-beam guardrail was supported by twenty-seven W152x13.4 by 1,346-mm long steel posts, spaced at 1,905 mm on center. The posts were installed in drilled holes in concrete, constructed by drilling three 203-mm diameter holes on 165- mm centers to a depth of 610 mm. The drilled holes were backfilled with compacted ASTM C33 coarse aggregate, size no. 57.

One full-scale vehicle crash test, using a 3⁄4-ton pickup truck, was performed …


Bridge Rails And Transitions For Pedestrian Protection, Nicholas R. Hiser, Ronald K. Faller, Dean L. Sicking, John R. Rohde, John D. Reid, Karla A. Polivka Jan 2003

Bridge Rails And Transitions For Pedestrian Protection, Nicholas R. Hiser, Ronald K. Faller, Dean L. Sicking, John R. Rohde, John D. Reid, Karla A. Polivka

Mid-America Transportation Center: Final Reports and Technical Briefs

It is desirable to protect pedestrians on bridges from motor vehicles. However, transition problems arise at the ends of bridges where the bridge rail, bridge rail end treatment, and pedestrian walkway compete for the limited available space. The objective of this study was to identify the most common scenarios in which the protection of pedestrians on bridges is desirable, and then to develop bridge rail and bridge rail end treatment configurations to accommodate those situations. The objective was achieved by performing a field investigation, a survey of state transportation agencies, and a literature review. Recommendations for the placement and general …


Cable Barrier Literature Review, Brian A. Coon, Ronald K. Faller, John D. Reid Jan 2002

Cable Barrier Literature Review, Brian A. Coon, Ronald K. Faller, John D. Reid

Mid-America Transportation Center: Final Reports and Technical Briefs

A literature review of cable barrier systems.


Crash Testing Of Michigan's Type B (W-Beam) Guardrail System - Phase Ii, Karla A. Polivka, Dean L. Sicking, John A. Rohde, Ronald K. Faller, James C. Holloway Jan 2000

Crash Testing Of Michigan's Type B (W-Beam) Guardrail System - Phase Ii, Karla A. Polivka, Dean L. Sicking, John A. Rohde, Ronald K. Faller, James C. Holloway

Mid-America Transportation Center: Final Reports and Technical Briefs

Michigan Department of Transportation's Type B (W-beam) longitudinal barrier system was constructed and crash tested. The barrier design was constructed with a 2.66-mm (12-gauge) thick W-beam rail totaling 53.34 m in length. The W-beam rail was supported by twenty-five W152.13.4 steel posts, each measuring 1,830-mm long, and four standard BCT posts, each measuring 1,080-mm long. Each of the steel posts had a 152.203 by 360-mm long standard wood offset blockout. Post spacings were 1,905-mm on center.

The research study included full-scale vehicle crash testing, using a 3/4-ton pickup truck. The test vehicle impacted at a speed of 99.8 km/hr and …


Development Of A 7.62-M Long Span Guardrail System – Phase Ii, Karla A. Polivka, Robert W. Bielenberg, Dean L. Sicking, Ronald K. Faller, John R. Rohde, Eric A. Keller Jan 1999

Development Of A 7.62-M Long Span Guardrail System – Phase Ii, Karla A. Polivka, Robert W. Bielenberg, Dean L. Sicking, Ronald K. Faller, John R. Rohde, Eric A. Keller

Mid-America Transportation Center: Final Reports and Technical Briefs

A 7.62-m long span guardrail system was developed for use over low-fill culverts. The long span design was constructed with two 2.66-mm (12-gauge) thick nested W-beam rails totaling 30.48 m in length. The nested W-beam rail was supported by sixteen W150x13.5 steel posts and six standard CRT posts, each with two 150x200x360 wood blockouts. Each post measured 1,830-mm long. Post spacings were 1,905-mm on center except for the 7.62-m spacing between the two CRT posts surrounding the unsupported span.

The research study included full-scale vehicle crash testing, using a 3⁄4-ton pickup truck. The test, impacting at a speed of 102.9 …


Compliance Testing Of Iowa’S Skid-Mounted Sign Device, Karla A. Polivka, Ronald K. Faller, John R. Rohde, James C. Holloway, Dean L. Sicking Jan 1999

Compliance Testing Of Iowa’S Skid-Mounted Sign Device, Karla A. Polivka, Ronald K. Faller, John R. Rohde, James C. Holloway, Dean L. Sicking

Mid-America Transportation Center: Final Reports and Technical Briefs

A wide variety of traffic control devices are used in work zones, some of which are nont ormally found on the roadside or in the traveled way outsideofthe work zones. These devices are used to enhance the safety of the work zones by controlling the traffic through these areas. Due to the placement of the traffic control devices, the devices themselves may be potentially hazardous to both workers and errant vehicles. The impact performance of many work zone traffic control devices is mainly unknown and to date limited crash testing has been conducted under the criteria of National Cooperative Highway …


Development Of A Tl-3 F-Shape Temporary Concrete Median Barrier, Ronald K. Faller, John R. Rohde, Barry T. Rosson, Richard P. Smith, Kenneth H. Addink Jan 1996

Development Of A Tl-3 F-Shape Temporary Concrete Median Barrier, Ronald K. Faller, John R. Rohde, Barry T. Rosson, Richard P. Smith, Kenneth H. Addink

Mid-America Transportation Center: Final Reports and Technical Briefs

A temporary concrete median barrier (CMB) was designed and tested for compliance under the Test Level 3 (TL-3) guidelines specified in the Recommended Procedures for the Safety Performance Evaluation of Highway Features, National Cooperative Highway Research Program (NCHRP) Report No. 350. The barrier is built to the new metric standards and has a traditional pin and loop configuration for interconnection. The objective of this research project was to develop and evaluate a standardized, temporary concrete barrier design while addressing the concerns for safety, economy, structural integrity, constructability, ease of installation, and maintenance. The resulting F-shape barrier segment is 3,800-mm …


A Synthesis Of Modern Rail Transportation Engineering Practices, Donald D. Cook Sep 1977

A Synthesis Of Modern Rail Transportation Engineering Practices, Donald D. Cook

Open Access Master's Theses (through 2010)

The 1970’s will go down in history as the decade in which the University of Nebraska – Civil Engineering Department expanded its academic interest to include the field of transportation. Railroad transportation and activities related to the instruction of planning, design and operation of railroads become a most important part of the transportation curriculum when viewed in the above context. Unfortunately, no modern comprehensive textbook exists for use in a rail transportation course.

The intent of this thesis is to provide a comprehensive source of data for use in the course of study in Railroad Transportation being developed by the …