Digital Commons Network^™

The Compressional Behaviour Of Perforated Elements, J. Rhodes, Falk D. Schneider

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The behaviour of stub columns with a series of different perforation patterns is examined on the basis of tests. The tests concentrate on plain channel cross sections with perforation layouts systematically varied to examine the effects of perforation position, dimensions and number on the section performance. The application of existing cold formed steel design codes to perforated members is examined on the basis of comparison with the tests, and various modifications to the design codes are considered to take perforations into account These are described and the comparison with test results is illustrated.

Elastoplastic Large Deflection Analysis Of Cold-Formed Members Using Spline Finite Strip Method, Shi-Lin Chen, Shao-Fu Li, Shan-Feng Fang

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The elastoplastic large deflection behaviour of cold-formed members is analysed by a nonlinear spline finite strip method. The method is developed using the principle of virtual work, based on the total Lagrangian description. It is used to deal with problems of geometric and material nonlinearity. The displacement function of a strip is expressed as the product of transverse interpolation polynomials and longitudinal B3-splines. The effect of arbitrary initial imperfections is taken into consideration. The influence of cold-bending residual stress on the local and overall behaviour of cold-formed lipped angle columns is investigated especially. The numeric examples show that the method …

Local Buckling Of Filled Sections, Howard D. Wright

CCFSS Proceedings of International Specialty Conference on Cold-Formed Steel Structures (1971 - 2018)

The buckling capacity of plates in contact with a rigid medium is greater than that for free plates. Such plates occur in sections filled with a suitably stiff material. Classical analysis is used to compare restrained and free plates.

Behavior Of Concrete And Slender Reinforced Concrete Columns Under Cyclic Axial Compression With Bidirectional Eccentricities, Byong Youl Bahn

Dissertations

A rational analysis of reinforced concrete (R/C) structures requires satisfactory modeling of the behavior of concrete under general loading patterns. The behavioral characteristics of concrete dominantly depends upon its load history. For the study of concrete behavior, parametric study and experimental investigation into the behavior of concrete under load history of random cycles are performed. Through parametric study, the applicability of the previous concrete models is examined and a physically motivated modeling for the cyclic stress-strain relationships is proposed. The present modeling of concrete under general cyclic loading is initiated to provide substantial applicability, flexibility of mathematical expressions and furthermore …

Theoretical Evaluation Of The Break Off Test For Concrete, Arjuna Priyara Ranasinghe

Dissertations

Strength of concrete is normally measured using the standard cylinder or cube. The measured strength is used for design. The accuracy of concrete strength is frequently challenged, particularly in large concrete structures where size effect of the test specimens is attributed for the differences. Many nondestructive tests were developed to evaluate concrete strengths. In recent years, it was obvious that these tests are unreliable. As the infrastructure decays, more nondestructive tests are required to evaluate the existing structures.

The Break Off Test is a recently developed nondestructive test. Although substantial amount of experimental investigations have been carried out on this …

Predicting The Future Fate Of Pcbs In Lake Hartwell, Alan W. Elzerman, Kevin J. Farley, Frank M. Dunnivant, Craig Cooper

Publications

No abstract provided.

Particle Trapping In Estuarine Tidal Flows, David A. Jay, Jeffery D. Musiak

Civil and Environmental Engineering Faculty Publications and Presentations

Particle trapping in estuarine turbidity maxima (ETM) is caused primarily by convergent mean and/or tidal fluxes of sediment. The result is an approximately bell-shaped along-channel distribution of vertically integrated, tidal cycle mean suspended sediment concentration. Observations from the Columbia River estuary suggest that (1) strong two-layer or internal along-channel residual and overtide flows are generated by time-varying stratification and (2) correlations between the near-bed velocity and the suspended sediment fields at these frequencies are important in landward transport of sediment. A new spatially and temporally integrated form of the sediment conservation equation has been derived to analyze this trapping process. …

Application Of A Risk Model To Quantify Relative Risk Of Remedial Actions, Timothy L. Fuller

Theses and Dissertations

To properly manage the Installation Restoration Program (IRP) in the future, Air Force remedial project managers (RPMs) need a metric to assist in the selection of remedial alternatives for the safe and effective clean up of waste contamination sites. If the baseline site risk assessment indicates that it is necessary to remediate a waste contamination site, it is important to the RPM that the selection process for remediation alternatives considers the potential human health and ecological risks associated with the proposed remediation process. In some instances, the risks may be significant when compared to the baseline conditions. The Air Force …

Volatile Organic Compound Emissions From Usaf Wastewater Treatment Plants In Ozone Nonattainment Areas, Brian A. Ouellette

Theses and Dissertations

In accordance with the 1990 Clean Air Act Amendments CAAA, this research conducts an evaluation of the potential emission of volatile organic compounds VOCs from selected Air Force wastewater treatment plants. Using a conservative mass balance analysis and process specific simulation models, volatile organic emission estimates are calculated for four individual facilities--Edwards AFB, Luke AFB, McGuire AFB, and McClellan AFB--which represent a cross section of the current inventory of USAF wastewater plants in ozone nonattainment areas. From these calculations, maximum facility emissions are determined which represent the upper limit for the potential VOC emissions from these wastewater plants. Based on …

A Preliminary System Dynamics Model Of A Constructed Wetland For The Mitigation Of Metals In Usaf Storm Water, Mark P. Smekrud

Theses and Dissertations

This thesis determines the potential removal and corresponding accumulation of trace metals from Air Force storm water in a constructed wetland through the use of a System Dynamics model. The goal is to determine whether constructed wetlands used as storm water best management practices provide efficient metal removal while creating only benign accumulations of such pollutants. Its purpose is to allow Base Civil Engineers and Environmental Managers a better tool to assess the long-term effects of a constructed wetland used as a storm water mitigation technique. The research is limited to the assessment of typical metal concentrations found in Air …

A Quantitative Method For Screening Pollution Prevention Program Options At United States Air Force Installations, Wayne M. Williams

Theses and Dissertations

US Air Force installations worldwide are required to implement pollution prevention (PP) programs designed to reduce the release of pollutants to the environment, and the Air Force uses opportunity assessments (OAs) to identify and evaluate waste producing processes that could benefit from a PP project. The OA process guidance provides extensive details on how to identify potential projects and on how to economically evaluate a project selected for implementation. However, it provides only cursory information about how to decide which projects should be selected for this evaluation. This thesis bridges that gap by providing a quantitative model to be used …

Optimal Pulsed Pumping For Aquifer Remediation When Contaminant Transport Is Affected By Rate-Limited Sorption: A Calculus Of Variation Approach, Richard T. Hartman

Theses and Dissertations

The remediation of groundwater contamination continues to persist as a social and economic problem due to increased governmental regulations and public health concerns. Additionally, the geochemistry of the aquifer and the contaminant transport within the aquifer complicates the remediation process to restore contaminated aquifers to conditions compatible with health-based standards. Currently, the preferred method for aquifer cleanup pump-and-treat has several limitations including, the persistence of sorbed chemicals on soil matrix and the long term operation and maintenance expense. The impetus of this research was to demonstrate that a calculus of variations approach could be applied to a pulsed pumping aquifer …

Modeling Trihalomethane Formation Potential From Wastewater Chlorination, Carol A. Mccormick

Theses and Dissertations

The deletion of federally mandated fecal coliform limits has led many states to review and modify their wastewater disinfection requirements. One issue in analyzing wastewater disinfection is the discharge of potentially carcinogenic halogenated organics formed during the chlorination process. This research investigates the formation of one class of the halogenated organics, the trihalomethanes. The applicability of using drinking water trihalomethane formation models for use with wastewater effluent is examined. Three models are compared for predictive capability by using measured trihalomethane values from previous research data. The results show that a previously developed model is applicable for use based on assumptions …

Simulation Of Hydrologic Influences On Wetland Ecosystem Succession, Robert A. Pompilio

Theses and Dissertations

This research focuses on the development of a simulation model to determine the effects of hydrological influences on a wetland ecosystem. The model allows perturbations to the inputs of various wetland data which in turn, influences the successional development of the ecosystem. This research consisted of converting a grassland ecosystem model to one which simulates wetland conditions. The critical factor in determining the success of wetland creation is the hydrology of the system. There are four of the areas of the original model which are affected by the hydrology. The model measures the health or success of the ecosystem through …

Decision Support Model To Compare Hazardous Waste Site Remediation Process Alternatives, Christopher E. Findall

Theses and Dissertations

This research focuses on the development of a decision support model to identify the preferred methods of site characterization and treatment technology identification using the principles of decision analysis theory. The model provides an effective decision making tool to evaluate and compare the feasibility of using alternative methods of completing the RIFS process. Given a specific site remediation project, the users of this model can enter site- specific cost, duration and likelihood values to determine the expected value for various alternative processes. This thesis postulates that the alternative having the highest expected value is considered the preferred alternative. In calculating …

Development Of An Analytical Hierarchy Process (Ahp) Model For Siting Of Municipal Solid Waste Facilities, Dimasalang F. Junio

Theses and Dissertations

Deciding on locations for municipal solid waste facilities is a difficult problem where qualitative criteria compete with quantitative economic and engineering criteria, in an environment that is highly political and emotional. State guidelines often describe different methodologies but fall short in offering a solution or a methodology in arriving at a solution. This study develops a decision modeling procedure, based on the Analytical Hierarchy Process (AHP), that can be used by public sector decision makers to locate and site municipal solid waste facilities. The applicability of the procedure is demonstrated at the City of Springfield, Clark County, Ohio. Research efforts …

Use Of Infrared Spectrometry To Determine The Effect Of Trichloroethylene Resident Time On Desorption Rates From Flint Clay, Peter T. Lapuma

Theses and Dissertations

This laboratory based thesis investigated the desorption rate of trichloroethylene (TCE) from flint clay while varying the resident time of TCE exposed to the clay. It is thought that in long contaminated soil, a majority of contaminant mass will become entrained within the interior of the soil particles to slowly desorb out of the soil over long periods of time. Recent studies suggest that the longer a contaminant is resident in soil, the longer the contaminant will take to desorb from the soil. To understand more about soil desorption, this experiment was developed using infrared spectroscopy to detect TCE vapor …

Modeling Of Ground Water Aquifer Remediation By Pulsed Pumping When Contaminant Transport Is Affected By Physical, Non-Equilibrium Sorption And Desorption, Jeffrey L. Caspers

Theses and Dissertations

This research postulates and demonstrates a modification incorporating rate-limited sorption effects in the USGS SUTRA code for cleanup of a hypothetical sandy aquifer by pump-and-treat remediation methods. Contaminant transport is assumed to be affected by advection, dispersion, and rate-limited sorption/desorption. Sorption is assumed to be either equilibrium or rate-limited, with the rate-limitation described by either a first-order law, or by Fickian diffusion of contaminant through a spherical immobile pore region. Solutions are arrived at by split operator methods for the transport and one-dimensional Galerkin solutions for the solute concentration equations. The resulting model is tested against an analytical Laplace transform …

Bulletin 4279 - Streamlining - An Environmentally Sustainable Drainage Network For The Swan Coastal Plain (Peel-Harvey Catchment), Garry Heady, Neil Guise

Bulletins 4000 -

Community Catchment Centre Pinjarra

A network of over 1400 kilometres of drains and modified natural waterways constructed by the Public Works Department criss-crosses the Peel-Harvey catchment. There are also over 3300 kilometres of minor drains and natural waterways in this same region.

The expansion of agriculture relied on this extensive drainage network, which was designed to ensure rapid drainage of the region. Unfortunately there was little regard to future environmental consequences.

Along with drainage water, these same drains now carry high loads of silt and nutrients. Many of the drains are also degraded and require expensive maintenance annually.

Conjunctive Management Of Surface Water And Ground Water Quantity And Quality: Conceptual And Functional Modelling Approach, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

This report discusses how to design a computer model to aid optimizing conjunctive management of groundwater and surface water quantity and quality. The report does not present a completed computer model, but rather discusses how a future model could be developed. The discussed modelling approach is termed PROMOD (PROposed methodology and MODel). Precursors to PROMOD are in current use, but are far from having all the attributes discussed here. The additional capabilities are important to address world needs.

Weather Forecasting, Cindy Preszler

Kentucky's Annual Forum on Transportation

No abstract provided.

In Situ Bioremediation Of Contaminated Unsaturated Subsurface Soils, Joseph L. Sims, R. C. Sims, R. R. Dupont, J. E. Mathews, M. M. Russell

Reports

An emerging technology for the remediation of unsaturated subsurface soils involves the use of microorganisms to degrade contaminants which are present in such soils. Understanding the processes which drive in situ bioremediation, as well as the effectiveness and efficiency of the utilization of these systems, are issues which have been identified by the Regional Superfund Engineering Forum as concerns of Superfund decision makers.

Regionalization Of Hydrologic Information In Tanzania (Low Flows), Onyekwuluje C

Tanzania Journal of Engineering and Technology (TJET)

Hydrologic infornjation is required for the planning and design Ofwater resource projects. However, Hydrologic infonnation is always lacking at points of interest. Regionalization is ained at estimating hydrologic infor- mation such as low flow statistics at ungauged sites. Hydrologic informa- tion from 63 catchments in Tanzania has been analysed. In this paper, pooled flow duration curves for 1, IO, 30, 60, and 90 days duration have been established. Regression equations between the low flow indices (i.e. 95 percentile and for a IO day duration, average annual yield (AAY), av- erage daily flow (ADE)) and catchment characteristics were developed. The pooled …

Evaluation Of Flood Routing Techniques For Incremental Damage Assessment, Enan Fakhri Jayyousi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Incremental damage assessment is a tool used to assess the justification for expensive modifications of inadequate dams. The input data to incremental damage assessment are the output from the breach analysis and flood routing. For this reason, flood routing should be conducted carefully. Distorted results from the flood routing technique or unstable modeling of the problem will distort the results of an incremental damage assessment, because an error in the estimated incremental stage will cause a certain error in the estimated incremental damages.

The objectives of this study were (1) to perform a comprehensive survey of the available dam break …

Modeling Of Natural Settling In A Trapezoidal Sedimentation Basin, Kent S. Wilkerson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The objectives of this thesis are to 1) review current theory relative to numerically modeling a trapezoidal settling basin, 2) develop a more appropriate model to better predict settling and deposition within a basin, and 3) confirm the accuracy of the model. The TSB (Trapezoidal Settling Basin) model was developed as part of this thesis. The Bureau of Reclamation's SETSIZE model performs similar analysis, but the TSB model makes significant improvements. The TSB model improves numerical modeling of a trapezoidal basin by allowing both sediment and sieve particle data, complex basin geometries with a multidimensional sediment deposition, and improved hydrograph …

Use Of Multispectral Aerial Videography For Jurisdictional Delineation Of Wetland Areas, James A. Shoemaker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multispectral aerial videography was used to reproduce the jurisdictional delineation of wetland area of approximately 50 hectares in Davis County, Utah Imagery from the system consisted of three-band composite with wavelengths covering 550 nm (±10 nm), 650 nm (±10 nm), and 850 nm (±10 nm). The site was overflown at three different flight dates during the 1992 growing season (June 2, July 22, October 1). Imagery resolution varied from 0.56 m to 0.81 m. Mosaiced images were analyzed with a Supervised clustering/maximum likelihood classifier, ISODATA clustering/Euclidan classifier, statistical clustering/maximum likelihood classifier, and fuzzy c-means clustering. Overall accuracies for wetland/upland designations …

Structural Behavior Of Perforated Web Elements Of Cold-Formed Steel Flexural Members Subjected To Web Crippling And A Combination Of Web Crippling And Bending, James E. Langan, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE A study of structural behavior was conducted and design equations were developed that account for the degradation in web crippling capacity caused by web openings for single web cold-formed steel flexural members. The sections were subjected to a concentrated load applied to one flange. The load application satisfied the AISI definition for either End-One-Flange or Interior-One-Flange loading. The research findings enable the current design provisions for sections without web openings to be modified by a reduction factor equation to obtain the web crippling capacity for sections with web openings. The modified capacity is considered for the web crippling capacity …

Bs News

Building Services Engineering

No abstract provided.

Pc Software For Optimizing Groundwater Contaminant Plume Capture And Containment, Richard C. Peralta, Herminio H. Suguino, Alaa H. Aly

Civil and Environmental Engineering Faculty Publications

Simulation/optimization (S/0) models can be used to speed the process of computing desirable groundwater pumping strategies for plume management. They make the process of computing optimal strategies fairly straightforward and can help minimize the labor and cost of groundwater contaminant cleanup.

Development And Evaluation Of A Nfweav Simulation Model For Weaving Areas Under Non-Freeway Condition, Wen-Min Pan

Theses

The development of a microscopic digital computer simulation model representing vehicle interaction at a weaving area under non-freeway condition is presented. Weaving areas are classified into two categories: 1. Weaving caused by merging and diverging of a ramp with an arterial, 2. On/off ramps connecting an arterial with a highway. The principal characteristics of the simulation model are the following: 1) a car following and lane changing model were used to represent vehicle movements; 2) an anti-collision check algorithm was developed for all vehicle movements; 3) driver merging urgency and follower courtesy model were developed for weaving vehicles. The simulation …