Civil Engineering Commons^™

Electromagnetic Waves In Contaminated Soils, Arvin Farid, Akram N. Alshawabkeh, Carey M. Rappaport

Civil Engineering Faculty Publications and Presentations

Soil is a complex, potentially heterogeneous, lossy, and dispersive medium. Modeling the propagation and scattering of electromagnetic (EM) waves in soil is, hence, more challenging than in air or in other less complex media. This chapter will explain fundamentals of the numerical modeling of EM wave propagation and scattering in soil through solving Maxwell’s equations using a finite difference time domain (FDTD) method. The chapter will explain how: (i) the lossy and dispersive soil medium (in both dry and fully water-saturated conditions), (ii) a fourth phase (anomaly), (iii) two different types of transmitting antennae (a monopole and a dipole), and …

Design, Behavior, And Performance Of Precast Concrete Bridge Barriers, Walid Rajab Alaywan

Doctoral Dissertations

The guidelines proposed by the NCHRP Report 350 pertaining to the safety of roadway hardware devices necessitated the evaluation of those devices. This study deals with the strength evaluation of precast concrete bridge railing.

A literature review was performed before the start of the study. Though many articles, reports, and publications were found regarding the testing of cast-in-place concrete barriers, such similar publications pertaining to precast concrete bridge railing were almost non-existent.

The theoretical work was performed using the yield line theory to predict the strength of the precast barrier. Though the theory was developed for cast-in-place barriers where the …

A Deterministic Method Of Predicting Long-Term Pile Capacity In Cohesive Soils After The Dissipation Of Excess Pore Water Pressure, Eric J. Steward

Doctoral Dissertations

Pile setup or freeze is a phenomenon where the bearing capacity of a pile increases over time both during and after the dissipation of pore pressure and the stabilization of lateral earth pressure. Driven piles gain capacity after installation because of the dissipation of excess pore pressure and soil aging. Incorporating accurate setup prediction into the design of the piles can significantly reduce the cost of many projects by reducing the size or number of required piles. Various simple, empirical mathematical models have been developed to predict pile setup. However, these models are often unreliable, resulting in very conservative designs. …

Predicting Deterioration Rate Of Culvert Structures Utilizing A Markov Model, Chenguang Yang

Doctoral Dissertations

A culvert is typically a hydraulic passage, normally placed perpendicular to the road alignment, which connects the upstream and downstream sections underneath an embankment, while also providing structural support for earth and traffic loads. The structural condition of culverts continues to deteriorate due to aging, limited maintenance budgets, and increased traffic loads. Maintaining the performance of culverts at acceptable levels is a priority for the U.S. Department of Transportation (DOT), and an effective maintenance of culvert structures can be greatly improved by introducing asset management practices. A priority list generated by traditional condition assessment might not provide optimum solutions, and …

Evaluation Of The In-Service Safety Performance Of Safety-Shape And Vertical Concrete Barriers, Francisco Daniel Albuquerque

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

Roadside concrete barriers have been widely used to protect errant motorists from hitting roadside hazards or obstacles. Two concrete barrier profiles, vertical and safety-shape, have been used for this purpose. The safety-shape profile has been shown to produce excessive vehicle climbing which tends to increase rollover propensity. The vertical profile, on the other hand, does not cause vehicle climbing, but it does produce higher lateral forces which may produce higher injury levels.

The objective of this research is to investigate which barrier profile is the safest based on real-world vehicle crash data. The safest barrier profile is defined as the …

The Effects Of Pedestrian Countdown Timers On Safety And Efficiency Of Operations At Signalized Intersections, Jacob N. Schmitz

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

Pedestrian countdown timers are becoming common at urban and suburban intersections. The added information that pedestrian countdown timers provide to pedestrians can also be used by approaching drivers. A before and after case study on the effects that pedestrian countdown timers have on safety and efficiency of operations was performed at two signalized intersections in Lincoln, Nebraska. The effects on both drivers and pedestrians were analyzed. Performance measures for pedestrian analysis include pedestrian compliance and average pedestrian walking speed. Performance measures for the driver analysis include probability of stopping and speed at the stop bar of vehicles during the yellow …

Effect Of Information On Driver's Risk At The Onset Of Yellow, Nathaniel P. Burnett

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

Intersection crashes average approximately 8,500 fatal and 900,000 injury accidents a year (1). At the onset of yellow at a high speed signalized intersection, a driver may encounter a region of the intersection approach, where they can neither stop safely nor be able to clear the intersection before the red indication. A wrong decision to stop when it would have been safer to proceed can lead to a severe rear-end collision. Conversely, a wrong decision to proceed through the intersection could lead to the driver running the red light and possibly causing a right angle collision. The traditional …

Identification Of Risk Factors Associated With Motorcycle-Related Fatalities In Ohio, Deogratias Eustace, Vamsi Krishna Indupuru, Peter W. Hovey

Civil and Environmental Engineering and Engineering Mechanics Faculty Publications

Out of the 7,138,476 motorcycles operating on U.S. roads, 346,925 were registered in the state of Ohio in the year 2007. Although motorcycles represent only 2.8% of all registered vehicles in the state of Ohio, motorcycling accounts for more than 13% of Ohio highway traffic fatalities. Since 2005, Ohio has had a distressing distinction of being among the fifteen states that have sustained more than half of all motorcycle fatalities recorded in the USA (NHTSA 2007; NHTSA 2008a). For the past ten years, the overall motorcycle crash fatalities have been increasing while the motor vehicle occupant crash fatalities have been …

Identifying Changes In Climatic Trends And The Fingerprints Of Landuse And Landcover Changes In The High Plains Of The Usa, Denis Mutiibwa

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Human activities such as conversion of natural ecosystem to croplands and urban-centers, deforestation and afforestation impact biophysical properties of land surface such as albedo, energy balance, and surface roughness. Alterations in these properties affect the heat and moisture exchanges between the land surface and atmospheric boundary layer. The objectives of this research were; (i) to quantitatively identify the High plains’ regional climate change in temperatures over the period 1895 to 2006, (ii) detect the signatures of anthropogenic forcing of LULC changes on the regional climate change of the High Plains, and (iii) examine the trends in evolving regional latent heat …

Development Of Guidelines For The Rating, Inspection, And Acquisition Of Railroad Flatcars For Use As Highway Bridges On Low-Volume Roads, Jason T. Provines, Robert Connor

Indiana Local Technical Assistance Program (LTAP) Technical Reports

Due to budget constraints, many state and county highway agencies are often forced to develop innovative and economical rehabilitation strategies for deteriorated bridges. One such option is to use a retired railroad flatcar for a bridge superstructure. Railroad flatcars can be found in many lengths, making them versatile options for replacing bridges of a range of span lengths up to about 90 feet. Railroad flatcars are also completely modular and lightweight, allowing for quick construction. Within Indiana, as well as other states, several of these bridge structures have been in service for many years.

Although their performance has been satisfactory, …

Estimating Highway Maintenance Work, Fifth Edition, Ohio Department Of Transportation, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This manual is founded upon a problem index that walks through a number of equations that will estimate the maintenance work required in areas such as bridge deck repair, chip and seal, crack sealing, mowing, road salt application, salt spreader calibration, and many more everyday road maintenance operations. The manual also includes an appendix to help with lengths, areas, volumes, rates, equivalents, and rules.

Steel Angle Section Members Under Combined Axial Load And Unsymmetric Bending, Maheshchandra Rajasekharan Phanibhushan

Civil & Environmental Engineering Theses & Dissertations

This thesis presents the outcome of an investigation into the experimental and theoretical behavior of steel angle section members under combined axial load and unsymmetric bending. Tests are conducted on a series of six angle section members provided with biaxial pinned-end boundaries about the cross-sectional non-principal axes. The end bending moments and axial load are applied in a quasi-static manner until the member load-carrying capacity is reached. The experimental load-deflection and load-strain curves are recorded. The theoretical analysis is based on a system of both elastic as well as materially nonlinear differential equations. The equations were solved using an iterative …

Flexural Behavior Of Interlocking Compressed Earth Block Shear Walls Subjected To In-Plane Loading, Bradley James Stirling

Master's Theses

This thesis investigates the flexural behavior of interlocking compressed earth block (ICEB) shear walls. In-plane cyclic tests were conducted to evaluate the performance of three flexure dominant large scale ICEB specimens: a slim wall with a 2:1 height to width aspect ratio, a flanged wall, and a wall with an opening at the center. Following the experimental investigation, two types of analyses were conducted for calculating the ultimate strength of flexure dominant ICEB walls: a nonlinear static analysis model assuming lumped plasticity and a plastic analysis model. In addition, incremental dynamic analysis was conducted to address the seismic performance of …

Computational Microstructure Modeling Of Asphalt Mixtures Subjected To Rate-Dependent Fracture, Francisco Aragao

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

Computational microstructure models have been actively pursued by the pavement mechanics community as a promising and advantageous alternative to limited analytical and semi-empirical modeling approaches. The primary goal of this research is to develop a computational microstructure modeling framework that will eventually allow researchers and practitioners of the pavement mechanics community to evaluate the effects of constituents and mix design characteristics (some of the key factors directly affecting the quality of the pavement structures) on the mechanical responses of asphalt mixtures. To that end, the mixtures are modeled as heterogeneous materials with inelastic mechanical behavior. To account for the complex …

Delayed Composite Action Coupled With Post-Tensioning For Cast In Place Bridge Deck Systems, Nathanael J. Toenies

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

Cast-in-place bridge decks are known to have transverse cracking early in the life of the bridge due to shrinkage and temperature effects. The cracks result from immediate composite behavior between the girder and the deck. For steel bridges, this bond is caused by shear studs welded to the steel beams and embedded in the cast-in-place deck. Prevention or closure of these cracks could greatly increase the durability of the bridge.

The following research focuses on introducing a system that will have delayed composite action, allowing strain in the concrete before it becomes composite with the girder. The system is meant …

Using Laser Scanning Cytometry To Investigate The Transport Of Nano-Scale Particles In Porous Media, Ryan May

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

The increased production of nanomaterials in recent years has been unprecedented. Given their potential toxicity, understanding the mechanisms controlling the transport of nanoparticles in the subsurface is important. In this study, a technique was developed for using a Laser Scanning Cytometer (LSC) to visualize and quantify the stable attachment of nano-scale particles. Experiments using three different size particles, 510 nm, 210 nm and 57 nm, in conjunction with a flow cell system containing saturated glass beads under varied injection duration, solution chemistry, Darcy velocity and solids content were performed. A technique for using the LSC data to develop spatial distributions …

An Enzymatic Treatment Of Soil-Bound Prions Effectively Inhibits Replication, Samuel Saunders, Jason C. Bartz, Kurt C. Vercauteren, Shannon L. Bartelt-Hunt

Department of Civil and Environmental Engineering: Faculty Publications

Chronic wasting disease (CWD) and scrapie can be transmitted through indirect environmental routes, possibly via soil, and a practical decontamination strategy for prion-contaminated soil is currently unavailable. In the laboratory, an enzymatic treatment under environmentally relevant conditions (22°C, pH 7.4) can degrade soil-bound PrPSc below the limits of Western blot detection. We developed and used a quantitative serial protein misfolding cyclic amplification (PMCA) protocol to characterize the amplification efficiency of treated soil samples relative to controls of known infectious titer. Our results suggest large (104- to >106-fold) decreases in soil-bound prion infectivity following enzyme treatment, demonstrating that a mild enzymatic …

Bs News July/August

Building Services Engineering

No abstract provided.

Probabilistic Assessment Of Drought Characteristics Using A Hidden Markov Model, Ganeshchandra Mallya, Shivam Tripathi, Sergey Kirshner, Rao S. Govindaraju

2011 Symposium on Data-Driven Approaches to Droughts

Droughts are evaluated using drought indices that measure the departure of meteorological and hydrological variables such as precipitation and stream flow from their long-term averages. While there are many drought indices proposed in the literature, most of them use pre-defined thresholds for identifying drought classes ignoring the inherent uncertainties in characterizing droughts. In this study, a hidden Markov model (HMM) [1] is developed for probabilistic classification of drought states. The HMM captures space and time dependence in the data. The proposed model is applied to assess drought characteristics in Indiana using monthly precipitation and stream flow data. The comparison of …

Assessment Of Statewide Intersection Safety Performance, Christopher M. Monsere, Todd Johnson, Karen Dixon, Jianfei Zheng, Ida Schalkwyk

TREC Final Reports

This report summarizes the results of an analysis of the safety performance of Oregon’s intersections. Following a pilot study, a database of 500 intersections randomly sampled from around the state of Oregon in both urban and rural environments was assembled. These intersections were categorized into eight types based on number of legs (3 and 4), land use (urban or rural) and traffic control (signalized or minor stop-control). These categories were chosen to align with the intersection types in AASHTO’s recently released Highway Safety Manual (HSM). Geometric and traffic control elements were supplemented by compiling crash data and volumes on the …