Civil and Environmental Engineering Commons^™

Factors Affecting The Seismic Behavior Of Segmental Precast Bridge Columns, Haitham Dawood, Mohamed Elgawady, Joshua Hewes

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This manuscript discusses the design parameters that potentially affect the lateral seismic response of segmental precast post-tensioned bridge piers. The piers consist of precast circular cross section segments stacked one on top of the other with concentric tendons passing through ducts made in the segments during casting. The bottommost segments of the piers were encased in steel tubes to enhance ductility and minimize damage. An FE model was used to investigate different design parameters and how they influence the lateral force — displacement response of the piers. Design parameters investigated included the initial post-tensioning stress as a percentage of the …

Increased Span Length For The Mgs Long-Span Guardrail System, Nicholas A. Weiland, Ronald K. Faller, Robert W. Bielenberg, John D. Reid

Nebraska Department of Transportation: Research Reports

No abstract provided.

Robust Geotechnical Design - Methodology And Applications, Lei Wang

All Dissertations

This dissertation is aimed at developing a novel robust geotechnical design methodology and demonstrating this methodology for the design of geotechnical systems. The goal of a robust design is to make the response of a system insensitive to, or robust against, the variation of uncertain geotechnical parameters (termed noise factors in the context of robust design) by carefully adjusting design parameters (those that can be controlled by the designer such as geometry of the design). Through an extensive investigation, a robust geotechnical design methodology that considers explicitly safety, robustness, and cost is developed. Various robustness measures are considered in this …

Robust Design Of Shield Tunnels ‒ Considering The Longitudinal Variation Of Input Parameters, Wenping Gong

All Dissertations

This dissertation, aimed at developing an improved design methodology for shield tunnels that explicitly considers design robustness against longitudinal variation of input parameters (such as soil parameters). To this end, a new solution model for shield tunnel performance analysis was first developed. In this new model, the random field concept was employed to model the longitudinal variation of input parameters. The input parameters (in the longitudinal domain) that had been generated with Monte Carlo simulation (MCS) were used as inputs for the tunnel longitudinal behavior analysis. Here, the finite element method (FEM) based upon Winkler elastic foundation theory was employed. …

Georgia's Water Policymaking Process And The Role Of Public Participation: Development And Analysis Of A Water Planning Process Evaluation Framework, Anna Eskridge

All Dissertations

This study analyzes the public's role in the regional water planning process that took place in the State of Georgia from 2009 to 2011. Specifically, this dissertation analyzes the extent to which a 'consensus-based' water planning process occurred by 1) examining the public participation plans that governed how the public was to contribute to the plan and policy formation, and 2) analyzing the public comments that were submitted at public meetings and commenting periods. By examining the participation plans and public comments, this study revealed the institutional, policy, legislative, and planning structures that influenced public participation in the regional water …

The Effect Of Infrastructure Changes On Railway Operations., Martin J.R. Schmidt 1966-

Electronic Theses and Dissertations

This paper makes use of standard simulation programs in combination with the tools of applied statistics to simulate railway operations. The purpose of the use of this tool is to evaluate and compare different possible kinds of railway infrastructure, like different types of signaling procedures, different network configuration or operational procedures. A railway system is a logistic network and because of the demand for improved railway operation, much work has been undertaken lately in this scientific field. However the author postulates the hypothesis based on a literature review that in a lot of these works there is a lack of …

Effect Of Enhanced Trackbed Support On Railway/Highway At-Grade Crossing Performance, Jerry G. Rose, Brett R. Malloy

Kentucky Transportation Center Research Report

This report documents the long-term performance of 89 railway/highway at-grade crossings in Kentucky and adjacent states that contain asphalt underlayment underneath the ballast. Asphalt underlayment increases load carrying capacity for trains and highway vehicles while enhancing the support structure’s waterproofing and confinement. The asphalt underlayment crossings studied were installed at sites that had historically exhibited poor performance and short service lives. Most of the crossing sites evaluated were 10-15 years old; however, their ages ranged up to 30 years. All of the crossings investigated have shown excellent performance since the installation of asphalt underlayments. No crossing failures, such as excessive …

Performance Of Frp-Retrofitted Concrete Bridge Columns Under Blast Loading, R. Zheng, P. Zohrevand, H. Erdogan, Amir Mirmiran

Civil Engineering Faculty Publications and Presentations

Contrary to military or essential government buildings, most bridges are designed without any consideration for blast resistance. Fiber-reinforced polymers (FRPs) can provide an effective means for strengthening of critical bridges against such loading. This study has focused on the effectiveness of FRP retrofitting in the dynamic response of reinforced concrete bridge columns under blast loading. Using a simplified equivalent I-section with a virtual material lumped at the two flanges; a lightly meshed uniaxial finite element model was developed and successfully validated against previous studies. The proposed model was then used for a thorough parametric study on the blast resistance of …

Identification Of Groundwater Sources For Municipal Wells Using Geochemical Data On The Platte Alluvial Aquifer And Underlying Limestone At The Lincoln Water Well Field Near Ashland Nebraska, Juanita Cruz Torres

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Alluvial aquifer systems where pumping of municipal wells induces recharge from the adjacent river are the primary source of water for many cities. The city of Lincoln, NE has a primary water source in an alluvial aquifer adjacent to the Platte River. The Lincoln Water System manages the stream/aquifer system by using integrated models for a better understanding during periods of high stress such as a drought. The integrated models set the limestone aquifer as an impermeable boundary to understand the alluvial aquifer system without having a secondary water source. The limestone aquifer is permeable and the purpose of this …

Axial Compression Behavior Of Unidirectional Carbon/Epoxy Tubes And Rods Before And After Impact, Ian Michael Oxborrow

Theses and Dissertations

Compression tests were performed on damaged and undamaged rods and tubes made from unidirectional carbon/epoxy composite and lightweight core materials. Tested samples represent local members in an open, three-dimensional, composite lattice structure. Testing was performed in order to establish effective core materials to use in order to increase the buckling length of local IsoTruss® members while maintaining low weight. Members were formed from T700SC-12K-50C carbon fiber with UF6639-100 resin. Core materials consisted of 3/8-inch (0.953 cm) outside diameter Teflon® rods, Teflon® tubes, nylon rods, nylon tubes, Ertalyte® rods, and Duratron® rods. All 3/8-inch (0.953-cm) cores were each surrounded by 50 …

Shear-Dominated Bending Behavior Of Carbon/Epoxy Composite Lattice Isobeam Structures, Kirsten Bramall Hinds

Theses and Dissertations

Composite lattice structures known as the IsoBeam™ made with unidirectional carbon/epoxy were manufactured and tested in shear-dominated bending. The manufacturing process consisted of placing tows of carbon fiber pre-impregnated with epoxy resin onto a pin-type mandrel to create members with interwoven joints. The members were consolidated with a half spiral aramid sleeve. The IsoBeam structure consists of two main types of members: longitudinal and diagonal members measuring nominally 0.4 in. (10.2 mm) and 0.2 in. (5.1 mm) in diameter, respectively. The hand-manufactured specimens measured nominally 6 in. (152.4 mm) high by 3 in. (76.2 mm) wide by 2 ft (0.61 …

Evaluation Of Current Empirical Methods For Predicting Lateral Spread-Induced Ground Deformations For Large Magnitude Earthquakes Using Maule Chile 2010 Case Histories, Ginger Emily Tryon

Theses and Dissertations

Improving seismic hazard analysis is an important part of building safer structures and protecting lives. Since large magnitude earthquakes are rarer than other earthquakes, it is harder to model seismic hazards such as lateral spread displacements for these events. Engineers are often required to extrapolate current lateral spreading models when designing utilities, bridges, and piers to withstand the ground displacements caused by earthquakes with magnitudes larger than 8.0. This study uses three case histories from the Maule Chile 2010 earthquake (Mw =8.8) to develop recommendations on which models are most accurate for large earthquake events and how to improve the …

Latin American Data Drought: An Assessment Of Available River Observation Data In Select Latin American Countries And Development Of A Web-Based Application For A Hydrometerological Database System In Spanish, Stephen Joseph Bolster

Theses and Dissertations

The demand and collection of hydrometeorological data is growing to support hydrologic and hydraulic analyses, and other studies. These data can amount to extensive information that requires sound data management to enable efficient storage, access, and use. While much of the globe is using technology to efficiently collect and store hydrometeorological data, other parts, such as developing countries, are unable to do so. This thesis presents an assessment of available river observations data in Latin American countries in Central America and the Caribbean. The assessment analyzes 1) access to available data, 2) spatial density of data, and 3) the temporal …

Design And Implementation Of An Inverse Modeling Framework Using The Method Of Anchored Distributions, Carlos Andres Osorio Murillo

Theses and Dissertations

Estimation of spatial random fields (SRFs) such as transmissivity or porosity is required for predicting groundwater flow and subsurface contaminant movement. Similarly, distributed parameter fields such as terrain roughness and evapotranspiration coefficients are required by other areas of environmental and earth sciences modeling. This dissertation presents an inverse modeling framework for characterizing SRFs called MAD#, which is an end-user software implementation of the Bayesian inverse modeling technique Method of Anchored Distributions (MAD). The MAD# framework allows modelers to “wrap” existing simulation modeling tools using an extensible driver architecture that exposes model parameters to the inversion engine. A compelling aspect of …

Traffic Safety Primer For Local Agencies, Indiana Ltap, Michigan Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

The purpose of this booklet is to empower local agency personnel to make informed decisions that can improve roadway safety in your community. By identifying and addressing potential roadway hazards, you can reduce the likelihood of a future traffic crash for your community and your family. Adapted by permission from the Michigan LTAP’s 2008 Publication What Elected Officials Need to Know About Traffic Safety (And What YOUR Constituents Expect YOU to Know!)

Estimating Field At-Rest Lateral Stress Coefficient And Liquefaction Resistance Of Aged Sands, Md Hossian

All Dissertations

Published results of laboratory tests to evaluate the influence of the at-rest lateral stress coefficient (K0) and the overconsoildation ratio (OCR) on liquefaction resistance of sands are reviewed in this dissertation. It is found that significant increase in liquefaction resistance can occur with high K0 and/or high OCR. A unique relationship between liquefaction resistance of isotropic and anisotropic normally consolidated sands exists based on the published laboratory data. Relationships between liquefaction resistance of overconsolidated sands and normally consolidated sands also have been shown in previous laboratory studies. Based on the previous studies, expressions for K0 and OCR correction factors (KK0 …

Disinfection Byproduct Formation Resulting From Settled, Filtered, And Finished Water Treated By Titanium Dioxide Photocatalysis, Brooke K. Mayer, Erin Daugherty, Morteza Abbaszadegan

Civil and Environmental Engineering Faculty Research and Publications

This study evaluated strategies targeting disinfection byproduct (DBP) mitigation using TiO₂ photocatalysis with varying influent water quality. A Purifics Photo-CAT Lab reactor was used to assess total trihalomethane (TTHM) and haloacetic acid (HAA) formation as a function of photocatalytic treatment using water from a conventional coagulation/flocculation/sedimentation process, granular activated carbon filtration, and a DBP hot spot in the water distribution system. Regardless of influent water quality, photocatalysis reduced DBP precursors; however, low-energy limited photocatalysis (m⁻³), exacerbated the production of TTHMs and HAA5s beyond initial levels. Accordingly, limited photocatalysis is not a suitable option when TTHMs and HAA5s …

Flexural Strengthening Of One-Way Continuous Reinforced Concrete Slabs With Cutoffs In Sagging And Hogging Regions, Jafar Husni Alshawa.

Theses

Installation of cutouts in existing reinforced concrete (CR) floor slabs to accommodate utility services reduces the slab load capacity and ductility. This research examines the effectiveness of using near-surface-mounted (NSM) carbon fiber reinforced polymer (CFRP) reinforcement to improve the flexural response of continuous RC slabs with cutouts. The study comprised experimental testing and analytical modeling. A total of eleven two-span RC slabs strips, 400 x 125 x 3800mm each were tested. Test parameters included the location of the cutouts, and amount and distribution of the NSM-CFRP reinforcement between the sagging and hogging regions.

Installation of a cutout in the sagging …

Sensitivity Of Columbia Basin Runoff To Long-Term Changes In Multi-Model Cmip5 Precipitation Simulations, Mehmet Demirel, Hamid Moradkhani

Civil and Environmental Engineering Faculty Publications and Presentations

In this study, we used precipitation elasticity index of streamflow, to reflect on the sensitivity of streamflow to changes in future precipitation. We estimated precipitation elasticity of streamflow from: (1) simulated streamflow by the VIC model using observed precipitation for the current climate (1963–2003); (2) simulated streamflow by the VIC model using simulated precipitation from 10 GCM - CMIP5 dataset for the future climate (2010–2099) including two different pathways (RCP4.5 and RCP8.5) and two different downscaled products (BCSD and MACA). The hydrological model was calibrated at 1/16 latitude-longitude resolution and the simulated streamflow was routed to the subbasin outlets of …

Cal Poly India Project, Derek Babine, Austen Hibler, Alex Hernandez

Mechanical Engineering

This report documents the research, ideation, and development of a solution, implemented by the Cal Poly India Sanitation Team per the request of Mr. Harish Bhutani, to solve the problem of hazardous human waste management in poor villages in India. The sponsor envisioned a universal design that would give each household in those villages access to a private toilet system because the current solution is open defecation in water sources and farming fields. The initial constraints required the project be low cost, not use of electricity or water, have the ability to cater to an 8-10 person household, and be …

Fast Fission Neutron Detection Using The Cherenkov Effect, Matthew Millard

All Theses

The Cherenkov effect in optically clear media of varying indices of refraction and composition was investigated for quantification of fast neutrons. The ultimate application of the proposed detection system is criticality monitoring. The optically clear medium, composed of select target nuclei, was coupled to a photomultiplier tube. Neutron reaction products of the target nuclei contained within the optical medium emit beta particles and gamma rays that produce Cherenkov photons within the medium which can be detected. Assessed media include quartz (SiO2), sapphire (Al2O3), spinel (MgAl2O4), and zinc sulfide (ZnS), which were irradiated with un-moderated 252Cf. Monte Carlo N-Particle (MCNP) code …

Optimizing Light Collection From Extractive Scintillating Resin In Flow-Cell Detectors, Amy Meldrum

All Theses

The objectives of this study were to investigate the changes in light collection efficiency for flow cell detector as various parameters are altered to find the optimum flow cell configuration. Columns with inner diameters of 0.16 cm, 0.48 cm, 0.79 cm, and 1.11 cm were packed with synthesized nonporous, un-functionalized beads to measure their detection efficiencies for solutions containing 210Po, 14C, or 90Sr/90Y. The average diameter of the beads used in the experiments was 147 µm ± 33 µm. The highest detection efficiency for 210Po was 15.3 ± 3.9% with the 1.11 cm diameter column. The 1.11 cm diameter column …

Using Gis To Prioritize Green Infrastructure Installation Strategies In An Urban Watershed, Lauren Owen

All Theses

This study seeks to quantify runoff volume generation and peak flow rates from the urban Sand River Headwaters to determine the most effective placement of additional green infrastructure in Aiken, SC. ArcMap 10.1, HEC-GeoHMS, and HEC-HMS were used to delineate a total outlet watershed along with subwatershed(s) for urban stormwater infrastructure system by 'burning' the stormwater system at an artificial elevation below the existing topologically-based Digital Elevation Model (DEM). The result was a higher resolution DEM that allowed for storm routing and subsequent volume and flow predictions compared to that based on the original DEM created by using Light Detecting …

Stochastic Wavenumber Estimation: Damage Detection Through Simulated Guide Lamb Waves, Garrison Stevens

All Theses

Structural Health Monitoring (SHM) is a field of research that seeks to identify the onset of damage in infrastructure systems such that catastrophic failures can be averted. Acoustic Wavenumber Spectroscopy (AWS) is an emerging SHM technique that can identify and locate change of thickness resulting from damage in thin plates through the estimation of the characteristic wavenumber. AWS measures the ultrasonically induced vibrations of thin plates by laser scanners and monitors the propagation of Rayleigh-Lamb waves through the structure. This method is particularly suitable for thin-walled structures such as those contained in pipes, airplanes, and wind turbine blades. While AWS …

Geotechnical Analysis Of The Foundation Of Fort Sumter National Monument Using Numerical Modeling, Daniel Kyser

All Theses

The foundational condition of the historical coastal fortification of Fort Sumter in Charleston, SC was analyzed though the use of numerical modeling. In this study, two-dimensional Finite Element (FE) analyses were conducted to assess the stability of the foundation-casemates-wall system in a coupled manner subjected to potential loadings such as ocean waves, storm surge and earthquake. The finite element model was verified by modeling the historical events (construction between 1820 and 1860, demolition due to artillery bombardment, reconstruction, earthquake, building of the Battery Huger, and the removal of fill from the parade ground) since the construction of the fort in …

Combined Numberical And Experimental Assessment Of Steel Roof Decks Subjected To Windborne Debris, Robert Roper

All Theses

In the summer of 2013, a steel roof deck manufacturer (Company A) approached Clemson University about testing their steel roof decking product to evaluate the performance of the steel roof deck to resist impact from tornado windborne debris using FEMA P-361 Design and Construction Guidance for Community Safe Rooms. To assist Company A in better serving their customers in areas prone to severe wind events and to facilitate use of their products in community safe rooms, debris impact tests were conducted on two cold-formed corrugated steel roof decking products. Community safe rooms are buildings that are constructed in accordance with …

Experimental Evidence For Colloid-Facilitated Transport Of Plutonium, Hilary Emerson

All Dissertations

Colloid-facilitated transport of the actinides has been observed previously in the field on the kilometer scale. The objective of this work is to investigate the mechanisms of colloid-facilitated transport with controlled settings and conditions. The experimental work in this dissertation investigates transport of a ternary complex with iron oxide colloids, organic ligands and actinides in the presence of quartz or a natural sandy soil as well as simplified systems building up to the ternary complexes. The first three papers investigate the following: (1) unsaturated transport of iron oxide colloids in a natural sandy soil lysimeter with and without natural organic …

Toward Understanding The Thermodynamics And Mechanisms Of Actinide Sorption Reactions, Shanna Estes

All Dissertations

The environmental fate of actinides is greatly influenced by interfacial reactions, including sorption onto solid surfaces. Because changes in the primary hydration sphere of the actinide are expected to greatly influence the thermodynamics (i.e., reaction enthalpy and entropy) of these reactions, examining actinide sorption thermodynamics may provide insight into actinide sorption mechanisms. Additionally, examining actinide sorption thermodynamics may enhance the ability to model or predict these reactions in environmental or engineered systems where variable or elevated temperatures are expected. However, few researchers have studied actinide sorption thermodynamics. Therefore, this research examined the thermodynamics of Eu(III) (a trivalent actinide analog), Th(IV), …

Modeling Sustainability In Renewable Energy Supply Chain Systems, Fei Xie

All Dissertations

This dissertation aims at modeling sustainability of renewable fuel supply chain systems against emerging challenges. In particular, the dissertation focuses on the biofuel supply chain system design, and manages to develop advanced modeling framework and corresponding solution methods in tackling challenges in sustaining biofuel supply chain systems. These challenges include: (1) to integrate 'environmental thinking' into the long-term biofuel supply chain planning; (2) to adopt multimodal transportation to mitigate seasonality in biofuel supply chain operations; (3) to provide strategies in hedging against uncertainty from conversion technology; and (4) to develop methodologies in long-term sequential planning of the biofuel supply chain …

The Effects Of Secondary Trapping Mechanisms On Geologic Storage Of Carbon Dioxide, Catherine Ruprecht

All Dissertations

The goal of this Dissertation is to further the understanding of secondary trapping mechanisms in geologic CO₂ storage systems to improve storage design and security. This Dissertation takes the form of three chapters. The objective of the first chapter was to analyze the storage performance of supercritical and brine saturated CO₂ injection strategies to determine their advantages and disadvantages on distribution and immobilization of CO₂ and pressure buildup. Results showed dissolved CO₂ injection was favorable in terms of storage security in all cases as it resulted in smaller areal extents on the caprock and did not …