Civil Engineering Commons^™

The Effects Of Airbags And Seatbelts On Occupant Injury In Longitudinal Barrier Crashes, Doug Gabauer, Hampton C. Gabler

Faculty Journal Articles

The Module Isomorphism Problem Reconsidered

Analyzing Motorists’ Responses To Temporary Signage In Highway Work Zones, Yong Bai, Kris Finger, Yue Li

Civil and Environmental Engineering Faculty Research and Publications

For decades, the importance of highway work zone safety has increased considerably with the continual increase in the number of highway work zones present on highways for repairs and expansion. Rural work zones on two-lane highways are particularly hazardous and cause a significant safety concern due to the disruption of regular traffic flow. In this study, researchers determined motorists’ responses to warning signs in rural, two-lane highway work zones. The researchers divided vehicles into three classes (passenger car, truck, and semitrailer) and compared the mean change in speed of these classes based on three different sign setups: portable changeable message …

Identification Of Physical Changes To A Steel Frame, Daniel Eric Means

Master's Theses

The thesis utilized physical testing and computer modeling to determine the feasibility of identifying a change to the mass or stiffness of a steel frame. Physical testing was performed using an accelerometer, linear shaker, and arbitrary function generator. Two methods of laboratory testing were developed: ambient vibration testing (AVT) and forced vibration testing (FVT). AVT was able to preliminarily identify the natural frequencies and mode shapes of the frame. FVT was able to precisely identify four distinct natural frequencies, mode shapes, and damping ratios. The baseline frame then underwent two physical changes: the addition of mass to its roof, and …

Optimal Train Control On Various Track Alignments Considering Speed And Schedule Adherence Constraints, Kitae Kim

Dissertations

The methodology discussed in this dissertation contributes to the field of transit operational control to reduce energy consumption. Due to the recent increase in gasoline cost, a significant number of travelers are shifting from highway modes to public transit, which also induces higher transit energy consumption expenses.

This study presents an approach to optimize train motion regimes for various track alignments, which minimizes total energy consumption subject to allowable travel time, maximum operating speed, and maximum acceleration/deceleration rates. The research problem is structured into four cases which consist of the combinations of track alignments (e.g., single vertical alignment and mixed …

Inter-Relationship Of Mechanical And Bio-Chemical Processes Governing The Settlement Of Municipal Solid Waste (Msw) Using The (C +H)/L Ratio, Joseph John Lifrieri

Dissertations

This research discusses the results of experimentation that determines the rates and magnitudes of consolidation and settlement of solid waste materials dependent upon their actual state of biodegradation decomposition and time in place. The state of decomposition of waste is determined by measuring its cellulose plus hemicellulose to lignin ratio ((C + H)/L). The samples were collected from bioreactors, at consecutive time intervals, to simulate states of decomposition.

Each sample was tested in consolidation to determine the value of the primary compression index C' _c, the secondary compression index "the inorganic creep rate" coefficient, C' _α, and the …

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

Mid-America Transportation Center: Final Reports and Technical Briefs

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

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

Mid-America Transportation Center: Final Reports and Technical Briefs

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

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

Mid-America Transportation Center: Final Reports and Technical Briefs

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

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

Mid-America Transportation Center: Final Reports and Technical Briefs

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

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

Mid-America Transportation Center: Final Reports and Technical Briefs

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

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

Mid-America Transportation Center: Final Reports and Technical Briefs

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

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

Mid-America Transportation Center: Final Reports and Technical Briefs

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

Computational Design Tool For Bridge Hydrodynamic Loading In Inundated Flows Of Midwest Rivers, Junke Guo, David M. Admiraal, Tian C. Zhang

Mid-America Transportation Center: Final Reports and Technical Briefs

The hydraulic forces experienced by an inundated bridge deck have great importance in the design of bridges. The proper estimation of loading exerted by the flow on the structure is important for design plans and is pertinent for evaluating its vulnerability. During a flood or hurricane highway bridges over the sea or other waterways may become partially or completely submerged. Flood flows add significant hydrodynamic loading on bridges, possibly resulting in the shearing or overturning of the bridge deck and failure of the bridge superstructures. The overall objective of the study was to establish validated computational practice to address research …

The Use Of Novel Non-Destructive Methods For Quality Control And Performance Evaluation Of Concrete Structures, Sree Nanukuttan, Niall Holmes, Sudarsan Srininvasan, Lulu Basheer, Muhammed Basheer, John Mccarter, Gerry Starrs

Conference papers

Concrete cover provides the first line of defense against the ingress of many deleterious substances into the concrete. Therefore, a measure of its transport properties is vital in assessing its long term performance in a given exposure condition. In new structures the rate of ingress of the deleterious substances could be monitored using array of electrical sensors that are embedded in the cover concrete. For structures that are currently in service, tests can be performed by removing cores from the structure (lab based tests) or by using tests that can be performed on the surface (in situ tests). Results relating …

A Study Of The Economical Feasibility Of Installing Heating, Ventilation, And Air-Conditioning Condensate Recovery System, Rafid M. Kully

Theses

The objective of this study is to establish a guide line or an analytical frame work to predetermine the economic benefits associated with the installation of Heating, Ventilation, and Air-Conditioning (HVAC) condensate recovery systems to capture the air-handler’s condensate water and use it as makeup water for the cooling tower. Some factors should be considered such as; the location, building operation, amount of outside air required, type of energy recovery system, and indoor conditions setup. Experimental data was used from Emory University in Georgia, where a condensate recovery system was installed and the condensate water from four air-handler units at …

Casing Pipe Damage Detection With Optical Fiber Sensors: A Case Study In Oil Well Constructions, Zhi Zhou, Jianping He, Minghua Huang, Jun He, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Casing pipes in oil well constructions may suddenly buckle inward as their inside and outside hydrostatic pressure difference increases. For the safety of construction workers and the steady development of oil industries, it is critically important to measure the stress state of a casing pipe. This study develops a rugged, real-time monitoring, and warning system that combines the distributed Brillouin Scattering Time Domain Reflectometry (BOTDR) and the discrete fiber Bragg grating (FBG) measurement. The BOTDR optical fiber sensors were embedded with no optical fiber splice joints in a fiber-reinforced polymer (FRP) rebar and the FBG sensors were wrapped in epoxy …

Developments In Monitoring Techniques For Durability Assessment Of Cover-Zone Concrete, W.J. Mccarter, T. M. Chrisp, G. Starrs, Niall Holmes, L. Basheer, M. Basheer, S. V. Nanukuttan

Conference papers

This paper outlines developments in the use of an embedded multi-electrode sensor to study the response of the cover-zone (surface 50mm) to the changing ambient environment. The sensor enables the measurement of the spatial and temporal distribution of the electrical properties of concrete and temperature within the cover-zone thereby allowing an integrated assessment of cover-zone concrete performance. Both laboratory and field results are presented to highlight the information that can be obtained from embedded sensors. When exposed to the natural environment, the temperature dependence of the electrical response is highlighted and standardization protocols are developed to account for this effect. …

Site Specific Modelling Of Traffic Loading On Highway Bridges, Bernard Enright, Eugene J. Obrien

Conference papers

Accurate traffic loading models based on measured weigh-in-motion (WIM) data are essential for the accurate assessment of existing bridges. Much work has been published on the Monte Carlo simulation of single lanes of heavy vehicle traffic, and this can easily be extended to model the loading on bridges with two streams of traffic in opposing directions. However, a typical highway bridge will have multiple lanes in the same direction, and various types of correlation are evident in measured traffic, such as groups of very heavy vehicles travelling together and heavy vehicles being overtaken by lighter ones. These traffic patterns affect …

Integrating Seasonal Climate Forecasts Into Institutional Decision-Making Processes, David Watkins

All ECSTATIC Materials

It is often challenging to integrate climate forecast use into actual decision-making processes, even when modeling demonstrates significant benefits from its use. Decision-making processes are guided by both formal policy frameworks, and the particular institutional structures under which decision-makers must operate. In addition, water is shared across multiple stakeholders, who are often represented by specific government or private sector agencies. These agencies face different costs depending upon the outcome of a forecast, and different preferences for risk. Depending upon the institutional and political arrangements for how decisions are made, these stakeholder interests may figure more or less strongly in water …

Estimation Of The Water Balance Using Observed Soil Water In The Nebraska Sandhills, Venkataramana Sridhar, K. G. Hubbard

Civil Engineering Faculty Publications and Presentations

Analyzing the dynamic hydrologic conditions of the Sandhills is critical for water and range management, sustainability of the Sandhills ecosystem as well as for dune stability. There are complex models available to quantify both surface and subsurface hydrological processes. However, we present in this study an application of a relatively simple model to arrive at best estimates of the water balance components. Using the Thornthwaite-Mather (TM) model, water balance components were estimated for 4 Automated Weather Data Network (AWDN) weather monitoring stations. Estimated averages of the water balance components suggested that mean annual precipitation of these four sites was only …