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2009

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Articles 121 - 150 of 214

Full-Text Articles in Civil Engineering

Effectiveness Of Temporary Traffic Control Measures In Highway Work Zones, Yingfeng Li, Yong Bai Mar 2009

Effectiveness Of Temporary Traffic Control Measures In Highway Work Zones, Yingfeng Li, Yong Bai

Civil and Environmental Engineering Faculty Research and Publications

In the United States, hundreds of people lose their lives each year and many more are injured due to vehicle crashes in the work zones. Over the years, temporary traffic control (TCC) measures have been developed and deployed in work zones. To continuously improve the safety, there is a need to identify the traffic control deficiencies in work zones by evaluating the effectiveness of existing TTC measures based on the real crash cases. In this study, researchers evaluated the effectiveness of several commonly used TTC methods using logistic regression techniques and various significance test methods including likelihood ratio test, score …


Bs News Mar 2009

Bs News

Building Services Engineering

No abstract provided.


Risk Mitigation For Highway And Railway Bridges, Andrzej S. Nowak, Marek Kozikowski,, Marta Lutomirska, Feb 2009

Risk Mitigation For Highway And Railway Bridges, Andrzej S. Nowak, Marek Kozikowski,, Marta Lutomirska,

Mid-America Transportation Center: Final Reports and Technical Briefs

Performance of the transportation network strongly depends on the performance of bridges. Bridges constitute a vital part of the transportation infrastructure system and they are vulnerable to extreme events such as natural disasters (i.e., hurricanes, earthquakes, floods, major storms), as well as hazards stemming from negligence and improper maintenance, collisions (vessels and vehicles), intentional acts of vandalism, and terrorist attacks. These structures must be protected but the current approach to risk is not rational. Therefore, the objective of this project is to develop efficient risk analysis procedures for assessment of the actual safety reserve in highway and railway bridges. The …


An Investigation Of Students’ Conceptual Understanding In Related Sophomore To Graduate-Level Engineering And Mechanics Courses, Devlin Montfort, Shane Brown, David Pollock Jan 2009

An Investigation Of Students’ Conceptual Understanding In Related Sophomore To Graduate-Level Engineering And Mechanics Courses, Devlin Montfort, Shane Brown, David Pollock

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Interviews were conducted with students from a sophomore-level mechanics of materials class, a sophomore/junior-level structures class, a senior-level steel design class and a graduate-level advanced steel design class to investigate students’ conceptual understanding of bending and normal stress. The graduate students generally demonstrated higher computational skill and confidence but they were not significantly different from the sophomores in terms of conceptual understanding. Interestingly, the seniors showed markedly lower confidence in their ability to solve the problems posed in the interviews. Common difficulties include a conceptual definition of stress and reasoning involving the normal stresses developed under bending.


Computer Aided Modeling Of Soil Mix Designs To Predict Characteristics And Properties Of Stabilized Road Bases, Charles W. Berryman Ph.D., Cpc, Wayne Jensen Ph.D., Tim Hensley P.E. Jan 2009

Computer Aided Modeling Of Soil Mix Designs To Predict Characteristics And Properties Of Stabilized Road Bases, Charles W. Berryman Ph.D., Cpc, Wayne Jensen Ph.D., Tim Hensley P.E.

Mid-America Transportation Center: Final Reports and Technical Briefs

Considerable data exists for soils that were tested and documented, both for native properties and properties with pozzolan stabilization. While the data exists there was no database for the Nebraska Department of Roads to retrieve this data for predicting soil properties. The conventional methods used to determine soil properties, such as maximum laboratory density and optimum moisture content, were tedious, labor intensive and time consuming. When soil stabilization is involved, more time and efforts are needed to determine maximum laboratory density, optimum moisture content and optimum pozzolan content. The objective of this project was to develop a computerized model to …


Inspector’S Manual For Mechanically Stabilized Earth Walls, Wayne Jensen Ph.D. Jan 2009

Inspector’S Manual For Mechanically Stabilized Earth Walls, Wayne Jensen Ph.D.

Mid-America Transportation Center: Final Reports and Technical Briefs

The scope of the project is to develop a condition rating system, creation of an inspector's manual to reference during inspection or address any training for inspectors at the district level. The research project will develop a MSE wall condition rating system and incorporate this system into the database being developed and create training and reference manuals


Investigation And Mitigation Of Driver Confusion At Modern Roundabouts, Aemal Khattak, Ram Bishu, Karen Schurr, Gregory Mcknight Jan 2009

Investigation And Mitigation Of Driver Confusion At Modern Roundabouts, Aemal Khattak, Ram Bishu, Karen Schurr, Gregory Mcknight

Mid-America Transportation Center: Final Reports and Technical Briefs

This research deals with two related issues: investigation and mitigation of roundabout elements that lead to driver confusion, and development of a flexible criteria matrix by which the Nebraska Department of Roads (NDOR) can evaluate arterial intersections to identify good candidates for conversion to roundabouts. The use of modern roundabouts along arterial roadways is relatively new in Nebraska. The first urban arterial roundabout was opened to traffic in June of 2002 at the intersection of 33rd and Sheridan Blvd in the City of Lincoln. Citizens and some professionals were somewhat skeptical of the capability of this roundabout to improve traffic …


Biodegradation Of The High Explosive Hexanitrohexaazaiso-Wurtzitane (Cl-20), Pelin Karakaya, Christos Christodoulatos, Agamemnon Koutsospyros, Wendy Balas, Steve Nicolich Nicolich, Mohammed Sidhoum Jan 2009

Biodegradation Of The High Explosive Hexanitrohexaazaiso-Wurtzitane (Cl-20), Pelin Karakaya, Christos Christodoulatos, Agamemnon Koutsospyros, Wendy Balas, Steve Nicolich Nicolich, Mohammed Sidhoum

Civil Engineering Faculty Publications

The aerobic biodegradability of the high explosive CL-20 by activated sludge and the white rot fungus Phanerochaete chrysosporium has been investigated. Although activated sludge is not effective in degrading CL-20 directly, it can mineralize the alkaline hydrolysis products. Phanerochaete chrysosporium degrades CL-20 in the presence of supplementary carbon and nitrogen sources. Biodegradation studies were conducted using various nutrient media under diverse conditions. Variables included the CL-20 concentration; levels of carbon (as glycerol) and ammonium sulfate and yeast extract as sources of nitrogen. Cultures that received CL-20 at the time of inoculation transformed CL-20 completely under all nutrient conditions studied. When …


Dynamic Evaluation Of New York State’S Aluminum Pedestrian Signal Pole System, Scott K. Rosenbaugh, Ronald K. Faller, Karla A. Lechtenberg, Robert W. Bielenberg, Dean L. Sicking, John D. Reid Jan 2009

Dynamic Evaluation Of New York State’S Aluminum Pedestrian Signal Pole System, Scott K. Rosenbaugh, Ronald K. Faller, Karla A. Lechtenberg, Robert W. Bielenberg, Dean L. Sicking, John D. Reid

Mid-America Transportation Center: Final Reports and Technical Briefs

The New York State Department of Transportation (NYSDOT) mounts pedestrian “hand/man” signals to aluminum

poles and uses frangible transformer bases to allow the system to break away. However, engineers at NYSDOT believed that the material properties of the aluminum poles themselves would allow the pedestrian signal poles to break away without the use of transformer bases. Elimination of the frangible transformer base would result in significant savings.

An aluminum pedestrian signal pole system was erected at the Valmont testing facility and tested with the Valmont- MwRSF/UNL pendulum with crushable nose in accordance with NCHRP Report No. 350 test designation no. …


Resilient Moduli Of Granular Base Materials Using A Modified Type 5 Gradation, David Newton Richardson, S. M. Lusher Jan 2009

Resilient Moduli Of Granular Base Materials Using A Modified Type 5 Gradation, David Newton Richardson, S. M. Lusher

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Missouri Department of Transportation (MoDOT) in collaboration with the Missouri Limestone Producers Association (MLPA) was interested in determining what effect a change in the Type 5 aggregate base gradation specification would have on the resilient modulus (Mr) of said aggregate. The proposed change would lower the minimum allowable total percentage of material passing the #4 (4.75 mm mesh) sieve from 35% to 25%, and the #30 (0.600 mm mesh) sieve from 10% to 5%. The remainder of the gradation specification would remain unchanged. The rationale for this proposed change is that some aggregate producers believe the change could help …


Flood Attenuation Studies, Michael Bruen, John O'Sullivan, Sangaralingam Ahilan, Zeinab Bedri Jan 2009

Flood Attenuation Studies, Michael Bruen, John O'Sullivan, Sangaralingam Ahilan, Zeinab Bedri

Reports

No abstract provided.


Catchment Modelling Tools And Pathways Review, Zeinab Bedri, Michael Bruen Jan 2009

Catchment Modelling Tools And Pathways Review, Zeinab Bedri, Michael Bruen

Reports

No abstract provided.


Mechanistic-Empirical Modeling In Network-Level Pavement Management, Scott Schram, Magdy Abdelrahman Jan 2009

Mechanistic-Empirical Modeling In Network-Level Pavement Management, Scott Schram, Magdy Abdelrahman

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Researchers and practitioners have long recognized the advantages of mechanistic modeling. As agencies implement the Guide for Mechanistic-Empirical Design of New and Rehabilitated Pavement Structures [referred to as the Mechanistic-Empirical Pavement Design Guide (MEPDG)] in the local project-level pavement management system (PMS), its potential as a planning tool in network-level analyses remains unrecognized. A unique, large-scale application of MEPDG is presented. The Nebraska Department of Roads uses a decision tree that systematically screens and identifies candidates for entry into a multiyear optimization program. The process uses linear deterioration rates that have been shown to provide an R2 value as …


Effects Of Aggregate Angularity On Mix Design Characteristics And Pavement Performance, Yong-Rak Kim, Leonardo T. Souza Jan 2009

Effects Of Aggregate Angularity On Mix Design Characteristics And Pavement Performance, Yong-Rak Kim, Leonardo T. Souza

Mid-America Transportation Center: Final Reports and Technical Briefs

This research targeted two primary purposes: to estimate current aggregate angularity test methods and to evaluate current aggregate angularity requirements in the Nebraska asphalt mixture/pavement specification. To meet the first research objective, various aggregate angularity tests were estimated with the same sets of aggregates and were compared by investigating their characteristics on testing repeatability, cost, testing time, workability, and sensitivity of test results. For the second objective, the effect of aggregate angularity on mixture performance was investigated by conducting laboratory performance tests (the uniaxial static creep test and the indirect tensile fracture energy test) of five mixes designed with different …


Quick Test For Percent Of Deleterious Material, David Newton Richardson Jan 2009

Quick Test For Percent Of Deleterious Material, David Newton Richardson

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The Missouri Department of Transportation (MoDOT) is considering the replacement of its deleterious materials test method (TM-71) with test methods that are more objective. MoDOT contracted with the Missouri University of Science and Technology (Missouri S&T) to develop a system of test methods. Nine quarry/ledge samples representing seven geologic formations (four limestones and three dolomites) were supplied by MoDOT. The ledge samples represented three aggregates each for use in concrete, asphalt, and granular base. Samples with controlled contamination were also tested, bringing the total to 18. The aggregates were subjected to fifteen test methods. This data, coupled with MoDOT historical …


A Refined True Triaxial Apparatus For Testing Unsaturated Soils Under Suction-Controlled Stress Paths, Diego D. Perez-Ruiz Jan 2009

A Refined True Triaxial Apparatus For Testing Unsaturated Soils Under Suction-Controlled Stress Paths, Diego D. Perez-Ruiz

Civil Engineering Dissertations - Archive

A novel, computer-driven, true triaxial (cubical) apparatus has been developed to test unsaturated soil specimens under suction-controlled multi-axial stress paths that are not achievable in a conventional cylindrical apparatus. The cubical cell implemented in this research work is a considerably refined version of those previously reported by Hoyos (1998) and Laikram (2007). The refined version is a servo-controlled, mixed boundary type of cell that allows for full control and real time measurements of matric suction, net principal stresses and soil deformations along a wide range of simple-to-complex stress paths induced on cubical specimens of unsaturated soil. The specimen seats on …


Performance Of Large Scale Steel Fiber Reinforced Concrete Deep Beam With Single Opening Under Monotonic Loading, Carlos Flores Jan 2009

Performance Of Large Scale Steel Fiber Reinforced Concrete Deep Beam With Single Opening Under Monotonic Loading, Carlos Flores

Civil Engineering Theses - Archive

The design of complex, discontinuous stress trajectory regions (D-regions) is complex in natureand cumbersome to design. The performance of a large scale steel fiber reinforced concrete (SFRC)deep beam with single opening under monotonic loading was tested under controlled conditions. Themain objective of this study was to see if Steel Fiber Reinforced Concrete (SFRC), used as a bettermaterial than reinforced concrete (RC) offered an alternate to the cumbersome and iterative stepsinvolved in strut-and-tie (STM) methodology. Additionally, a similar reinforced concrete (RC) specimenwas tested under the same controlled condition designed with classical strut-and-tie model designmethodology reinforced using conventional steel bars.Material testing was …


Theoretical Feasibility Study For A Conceptual Approach To Trenchless Replacement Of Culverts, Diego R. Calderon Jan 2009

Theoretical Feasibility Study For A Conceptual Approach To Trenchless Replacement Of Culverts, Diego R. Calderon

Civil Engineering Theses - Archive

Culvert damage and collapses and their renewal alternatives are a raising concern in today's infrastructure topics. In most cases damages are irreversible; however, in many cases opportunities exist to correct and renew. While conventional open-cut construction brings inconvenience to the public, trenchless technology brings a greener, reliable and more socially acceptable alternative to renew culverts. Considering the strong dependency on highway transportation by the American lifestyle, collapses of culverts in major roads may produce chaotic traffic redirections. To reduce this risk, this research sets a path for a construction and feasibility study on a new culvert replacement method based on …


Use Of Electrical Resistivity And Multichannel Analysis Of Surface Wave Geophysical Tomography In Geotechnical Site Characterization Of Dam, Joshua Lee Hubbard Jan 2009

Use Of Electrical Resistivity And Multichannel Analysis Of Surface Wave Geophysical Tomography In Geotechnical Site Characterization Of Dam, Joshua Lee Hubbard

Civil Engineering Theses - Archive

Performance of geotechnical site characterization is a primary function of geotechnical engineers. Generalizations required to extrapolate conventional geotechnical boring data can limit the effectiveness of site assessments. Advancements in geophysical technology have simplified means of data acquisition and interpretation of electrical and seismic testing, allowing a broader audience of practitioners to utilize methods for various engineering and environmental applications. In this study, electrical resistivity and multichannel analysis of surface waves (MASW) seismic geophysical methods are used to expound upon previous geotechnical sampling and in situ testing conducted at an earthen dam site in East Texas. Findings from this study show: …


A New Paradigm In User Equilibrium - Application In Managed Lane Pricing, Asapol Sinprasertkool Jan 2009

A New Paradigm In User Equilibrium - Application In Managed Lane Pricing, Asapol Sinprasertkool

Civil Engineering Dissertations - Archive

Ineffective use of the High-Occupancy-Vehicle (HOV) lanes has the potential to decrease the overall roadway capacity during peak periods. Excess capacity in HOV lanes during peak periods can be made available to other types of vehicles, including single occupancy vehicles (SOV) for a price (toll). Such dual use lanes are known as "Managed Lanes." The main purpose of this research is to propose a new paradigm in user equilibrium to predict the travel demand for determining the optimal fare policy for managed lane facilities. Depending on their value of time, motorists may choose to travel on Managed Lanes (ML) or …


Durability Studies On Stabilization Effectiveness Of Soils Containing Different Fractions Of Montmorillonite, Aravind Pedarla Jan 2009

Durability Studies On Stabilization Effectiveness Of Soils Containing Different Fractions Of Montmorillonite, Aravind Pedarla

Civil Engineering Theses - Archive

Stabilization of clays with additives like lime and cement has been practiced for several years and worked well in improving the subgrades. Though this practice is used widely, there were cases where the treated subgrades exhibited premature failures. Many departments of transportation (DOT) agencies in the United States have had subgrade failures even after stabilization with chemical additives due to loss of stabilizer over a time period, or a stabilizer being ineffective in some soils. The design based on PI and gradation of soil followed by many DOTs is quite misleading due to the lack of inclusion of basic soil …


Failure Analysis Of A Mechanically Stabilized Earth (Mse) Wall Using Finite Element Program Plaxis, Tahsina Mahmood Jan 2009

Failure Analysis Of A Mechanically Stabilized Earth (Mse) Wall Using Finite Element Program Plaxis, Tahsina Mahmood

Civil Engineering Theses - Archive

Mechanically Stabilized Earth (MSE) retaining walls have been increasingly used in many federal, state and private projects over the last 20 years. MSE walls are reliable, constructible, and cost effective. However, failure of MSE wall has become a problem for all agencies using them. This study presents the failure analysis of a segmental block, MSE retaining wall located in Rockville, Maryland. The top of MSE wall moved about 12 inches to 18 inches. An extensive geotechnical investigation program was undertaken to investigate the MSE wall failure. This study presents the results of investigations to determine the causes of failure. The …


Development And Benefits Of A Leed Project Management Database, Teri Schmig Jan 2009

Development And Benefits Of A Leed Project Management Database, Teri Schmig

Civil Engineering Theses - Archive

The U.S. Green Building Council is a non-profit community of industry leaders working to make green buildings available to everyone. The documentation process for achieving Leadership in Energy and Environmental Design (LEED® ) certification is highly complex and more time-consuming than necessary with currently employed systems. This thesis explains the need for development of a relational database as a means to increase the efficiency of the documentation process to meet LEED® requirements. This database will provide the construction project team a relational platform that guides the user through the LEED® administration and certification process. By developing a LEED® specific project …


Development Of Brownfield Database Using Gis, Jubair Hossain Jan 2009

Development Of Brownfield Database Using Gis, Jubair Hossain

Civil Engineering Theses - Archive

Brownfields are abandoned, idled or underutilized industrial or commercial sites where expansion or redevelopment is complicated by actual or perceived environmental contamination. Brownfields may be as small as a vacant city lot or as large as an abandoned manufacturing facility occupying several hundred acres. The extent of contamination encountered at brownfield sites may range from minor surface debris to extensive, dangerous soil and ground-water contamination. Concerning the communities in which brownfields are located, redevelopment may improve community appearance and image, relieve associated health and environmental concerns and produce a beneficial economic effect through increased property values and employment opportunities.The overall …


Level-Of-Service And Traffic Safety Relationship: An Exploratory Analysis Of Signalized Intersections And Multiland High-Speed Arterial Corridors, Ana Almonte-Valdivia Jan 2009

Level-Of-Service And Traffic Safety Relationship: An Exploratory Analysis Of Signalized Intersections And Multiland High-Speed Arterial Corridors, Ana Almonte-Valdivia

Electronic Theses and Dissertations

Since its inception in 1965, the Level-of-Service (LOS) has proved to be an important and practical "quality of service" indicator for transportation facilities around the world, widely used in the transportation and planning fields. The LOS rates these facilities' traffic operating conditions through the following delay-based indicators (ordered from best to worst conditions): A, B, C, D, E and F. This LOS rating has its foundation on quantifiable measures of effectiveness (MOEs) and on road users' perceptions; altogether, these measures define a LOS based on acceptable traffic operating conditions for the road user, implying that traffic safety is inherent to …


Resilient Moduli Of Typical Missouri Soils And Unbound Granular Base Materials, David Newton Richardson, Thomas M. Petry, Yu-Ning Louis Ge, Y. P. Han, S. M. Lusher Jan 2009

Resilient Moduli Of Typical Missouri Soils And Unbound Granular Base Materials, David Newton Richardson, Thomas M. Petry, Yu-Ning Louis Ge, Y. P. Han, S. M. Lusher

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The objective of this project is to accurately determine the resilient moduli for common Missouri subgrade soils and unbound granular base materials in accordance with the AASHTO T 307 test method. The test results included moduli data from 27 common subgrade soils out of the 99 Missouri soil associations and from 5 unbound granular bases. These materials were tested at their optimum water content and at an elevated water content, which would normally occur as a worse case scenario during the life of a pavement. The five unbound granular base materials were tested at two different gradations (high and low …


A Comprehensive Study Of Recycled Concrete Aggregates As A Drainable Base Layer For Pavements, Juan Bosquez Jan 2009

A Comprehensive Study Of Recycled Concrete Aggregates As A Drainable Base Layer For Pavements, Juan Bosquez

Civil Engineering Dissertations - Archive

The use of recycled materials in construction is becoming increasingly popular due to the shortage of raw materials. Coupled with the environmental concerns surrounding the quarrying of natural minerals, waste materials are being considered as viable replacement sources. By recycling waste materials, available landfill space is increased and costs of transportation are reduced. This dissertation study was conducted to evaluate the use of recycled concrete aggregates as flexible base as per the requirements of the Texas Department of Transportation (2004). Two sources of recycled aggregates and one source of natural limestone aggregate were collected from the Dallas/Fort Worth Area and …


Nonlinear Dynamic Analysis Of Hybrid Frames, Dobrinka Radulova Jan 2009

Nonlinear Dynamic Analysis Of Hybrid Frames, Dobrinka Radulova

Civil Engineering Theses - Archive

This study proposes a hybrid frame system consisting of rigid and semi-rigid connections subjected to a dynamic loading. Two building geometries are chosen to represent low-rise and high-rise buildings. Multiple locations for placement of semi-rigid connections are proposed, and the hybrid systems with the most efficient energy dissipation are identified. During this analysis, five earthquake records are used to provide a spectrum of frequencies. Five practical semi-rigid connection types and one connection with analytical parameters are also modeled into the selected hybrid combinations by applying zero-length springs at the ends of beams, in which their nonlinear constitutive relation is defined …


Investigation Of Damage Detection Methodologies For Structural Health Monitoring, Mustafa Gul Jan 2009

Investigation Of Damage Detection Methodologies For Structural Health Monitoring, Mustafa Gul

Electronic Theses and Dissertations

Structural Health Monitoring (SHM) is employed to track and evaluate damage and deterioration during regular operation as well as after extreme events for aerospace, mechanical and civil structures. A complete SHM system incorporates performance metrics, sensing, signal processing, data analysis, transmission and management for decision-making purposes. Damage detection in the context of SHM can be successful by employing a collection of robust and practical damage detection methodologies that can be used to identify, locate and quantify damage or, in general terms, changes in observable behavior. In this study, different damage detection methods are investigated for global condition assessment of structures. …


Reduced Visibility Related Crashes In Florida: Crash Characteristics, Spatial Analysis And Injury Severity, Al-Ahad Ekram Jan 2009

Reduced Visibility Related Crashes In Florida: Crash Characteristics, Spatial Analysis And Injury Severity, Al-Ahad Ekram

Electronic Theses and Dissertations

Roadway crashes related to vision obstruction due to fog/smoke (FS) conditions constitute a challenge for traffic engineers. Previous research efforts mostly concentrated on the snow and rain related crashes. Statistics show that Florida is among the top three states in terms of crashes due to vision obstruction by FS. This research culminated in a comprehensive study of fog and smoke related crashes in the state of Florida. The analysis took into account the crashes that occurred between 2003 and 2007 on Florida state roads. Spatial analysis and injury severity analysis have been conducted and significant results have been identified. The …