Civil Engineering Commons^™

Performance Rating Of De-Icing Chemicals For Winter Operations, Barbara M. Gerbino-Bevins

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

The cost of deicing chemicals is a significant part of the Nebraska Department of Road's winter maintenance budget. Many products are available for use in highway and bridge deicing and new products are introduced each year. The objectives of this research are to develop a laboratory test to evaluate the performance of chemical deicers, to investigate national, state, and local standards, and to develop best maintenance practices to optimize the use of chemical deicers.

This research project consists of two phases:

Phase 1: conduct a literature survey to find data from existing laboratory tests used to evaluate deicer performance.

Phase …

Application Of Shredded-Tire Biofilter And Membrane Bioreactor For Greywater Reclamation, Meng Hu

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

Water scarcity is a pressing global issue. Greywater (GW) reclamation is a viable option to reduce freshwater demand. The objectives of this work were to: a) evaluate the feasibility of the combination of shredded tire biofilter (STB) technology and membrane bioreactor (MBR) technology in GW reclamation; b) study the effects of various parameters on STB performance; and c) understand the fouling mechanisms to lower the energy consumption in MBRs. Bench-scale STBs and MBRs (flat-sheet membranes) were constructed to address the first two objectives, while an independent membrane (hollow-fiber membranes) fouling experiment was designed for the third objective.

It was found …

The Effects Of Fundamental Mixture Parameters On Hot-Mix Asphalt Performance Properties, Wenbin Zhao

All Dissertations

Asphalt pavements are composed of three components: aggregate, asphalt binder, and air. In the process of plant production and on-site construction, the construction quality can vary in the three component and the variability can further affect a pavement's future performance.. This research identifies aggregate gradation, binder content, and air voids content as the fundamental parameters. Understanding the fundamental parameters' influence on the HMA mixture's performance properties can provide valuable information on how to improve the current quality insurance practice. The objective of this study is to conduct well-controlled experiments to investigate how mix gradation, air voids and small range binder …

Assessing The Surface Energy Balance Components In The Snake River Basin, W Thilini Ajanthik Jaksa

Boise State University Theses and Dissertations

This study investigated the interaction of land-surface processes and vegetation in both natural ecosystems and irrigated agricultural lands in a semiarid region using the Noah land surface model (LSM) in combination with the Weather Research and Forecasting (WRF) Model. This study was conducted in the semiarid Snake River plains of south central Idaho comprising of both natural vegetation and agricultural lands. This area is characterized by warm, dry summers with irrigation being the main moisture source during the growing season. In order to properly represent the conditions of agricultural lands and also to investigate the effects of irrigation on land-surface …

Applied And Mechanistic Studies Of Microbial 17beta-Estradiol Degradation, Zhongtian Li

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

The presence of natural estrogens, a class of endocrine disrupting compounds, in water has caused increasing concerns over their adverse impacts on the health of aquatic eco-systems and human beings. In this study, adsorption characteristics of two natural estrogens, 17β-estradiol (E2) and estrone (E1), on granular activated carbon (GAC) were investigated in isotherm tests and in a GAC column. The GAC column was then converted to a biologically active carbon (BAC) column and the removal efficiency of E2 and its primary biodegradation intermediate E1 were monitored. During BAC operation, the impacts of various reactor operation parameters, such as the carbon …

Roadside Grading Guidance, Kevin D. Schrum

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

Provisions for the design of roadside foreslopes are not readily available, and as a result, engineering judgment is often employed. Unfortunately, this can lead to inconsistent designs, where, inevitably, some designs will be too costly and other designs will be too dangerous. Therefore, a design guide was created to lend consistency to the design of these foreslopes while maintaining the most economical and safe design.

This design guide was prepared after conducting a benefit-cost analysis using the Roadside Safety Analysis Program (RSAP). A large test matrix was developed in an attempt to simulate the most possible scenarios, leaving interpolation to …

Relating Climatic Attributes And Water Resources Allocation: A Study Using Surface Water Supply And Soil Moisture Indices In The Snake River Basin, Idaho, David J. Hoekema, Venkataramana Sridhar

Civil Engineering Faculty Publications and Presentations

Climate change forced by anthropogenic activities has been ongoing since at least the beginning of the industrial revolution. Part of the recent warming in the western United States has been attributed to anthropogenic climate change. This research seeks to answer the basic question of how declining streamflow, increasing temperatures, and fluctuation in precipitation have impacted water resource allocation in the Snake River Plain over the past 35 years (1971-2005). Understanding how changes in climatic attributes have historically impacted water allocation should help water managers better understand how projected climate change may influence allocation. Annual and monthly diversion trends from 62 …

Theoretical And Numerical Research On Sediment Transport In Pressurized Flow Conditions, Zhaoding Xie

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

Research of river bed erosion is an important part of designing bridges and transportation networks since the stability and hydrodynamic response of bridges critically depends on river bed scour. The engineering designers traditionally focus on the local scour around hydraulic structures, such as piers and abutments, in open channel flow. The pressurized scour under a submerged bridge deck is seldom researched.

In this study, the commercial CFD codes, FLOW3D and STARCCM+, are adopted to simulate pressure scour under a bridge deck with six girders. Several limitations for FLOW3D are found during its application of sediment transport model: a) the scour …

Fourier Finite Element Analysis Of Laterally Loaded Piles In Elastic Media Internal Geotechnical Report 2011-1, William Higgins, Dipanjan Basu

Technical Reports

Laterally loaded piles are analyzed using the Fourier finite element method. Pile response was observed to be a function of the relative stiffness of pile and soil and of the pile slenderness ratio. The analysis is mostly performed for piles embedded in elastic soil with constant and linearly varying modulus although the pile response in two-layer soil profiles is also investigated. Equations describing pile head deflection, rotation and maximum bending moment are proposed for flexible long piles and stubby rigid piles. The design equations were developed after plotting the pile responses as functions of pile-soil stiffness ratio and pile slenderness …

Sustainability In Geotechnical Engineering Internal Geotechnical Report 2011-2, Aditi Misra, Dipanjan Basu

Technical Reports

The built environment serves as a dynamic interface through which the human society and the ecosystem interact and influence each other. Understanding this interdependence is key to understanding sustainability as it applies to civil engineering. There is a growing consensus that delivering a sustainable built environment starts with incorporating sustainability thoughts at the planning and design stages of a project. Geotechnical engineering is the most resource intensive of all the civil engineering disciplines and can significantly influence the sustainability of infrastructure development because of its early position in the construction process. In this report, a review is made of the …

Climate Change Impacts: An Assessment For Water Resources Planning And Management In The Pacific Northwest Of The U.S, Venkataramana Sridhar, Xin Jin

Civil Engineering Faculty Publications and Presentations

Assessing the hydrological impacts of climate change in the Pacific Northwest (PNW) region of the United States is important. Many global circulation models (GCMs) have a wide range of temperature and precipitation predictions for the PNW region (Bureau of Reclamation, 2011). Numerous studies have reported that decreasing snow pack, increasing temperatures and decreasing streamflow for many basins. For instance, Mote (2003) indicates that annual average temperatures in the Northwest rose faster than the global average during the 20th century. This warming occurred mostly during the winter and spring. The predominance of winter and spring warming, especially in regard to extreme …

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 …

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 …

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 …

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 …

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, …