Civil and Environmental Engineering Commons^™

Predicting Seepage Of Leachate From The St. Johns Landfill To Ground And Surface Water Systems, Kevin A. Schock

Dissertations and Theses

Determination of the vertical and horizontal groundwater hydraulic gradient within a landfill is the first step in determining the potential of groundwater contamination from the landfill leachate. The length of a study and the frequency at which measurements are recorded can greatly affect the description of the local groundwater environment. A more comprehensive analysis can be preformed for longer periods of study and greater measurement frequency. The intent of this study was to install a continuous groundwater level monitoring system around the st. Johns Landfill for a minimum study length of one year. This would allow a more thorough study …

Gravity Sedimentation: A One-Dimensional Numerical Model, Joanna Robin Karl

Dissertations and Theses

A large fraction of the current cost of wastewater treatment is from the treatment and disposal of wastewater sludge. Improved design, energy efficiency, and performance of dewatering facilities could significantly decrease transport and disposal costs.

Dewatering facilities are designed based on field experience, trial and error, pilot plant testing, and/or full scale testing. Design is generally time-consuming and expensive. A full-scale test typically consists of side-by-side operation of 4 to 5 full-scale dewatering units for several weeks to more than 6 months. Theoretical modeling of the physics of dewatering units such as the belt filter press, based on laboratory determined …

One-Dimensional Computer Modeling Of Thermal And Water Quality Characteristics Of Coldwater Lake, Wa, David Kevin Whitaker

Dissertations and Theses

Coldwater Lake is a new lake formed when a massive mudflow down the Toutle River Valley, caused by the eruption of Mount St. Helens on May 18, 1980, blocked the natural outlet of Coldwater Creek. This research utilizes physical, biological and chemical data collected at Coldwater Lake during the sun1mers of 1989 and 1990 to calibrate and verify the one-dimensional computer models CE-THERMRl and CE-QUAL-Rl for Coldwater Lake. CE-THERM-R1 was used to simulate thermal characteristics in Coldwater Lake during the summer stratification periods of 1989 and 1990. The model was calibrated to 1989 data and was verified with 1990 data. …

The Use Of Laboratory Testing To Understand The Behavior Of Collapsible Soil Upon Wetting, Martha H. Denham

Dissertations and Theses

In developing a constitutive model that could predict the settlement due to the collapse, several goals needed to be met. These were to gain an understanding of the collapse phenomenon, knowing the soil properties at the natural water content and how they change after collapse, and develop and test the new model. It was felt that laboratory testing could be of use. The types of test conducted included use of the Oedometer, Pressuremeter, and Triaxial tests. The material that was used for the testing was a "generic" soil manufactured out of diatomite. In all of the tests the soil was …

Improved Methodology For Limit States Finite Element Analysis Of Lattice Type Structures Using Nonlinear Post-Buckling Member Performance, Markus Ostendorp

Dissertations and Theses

In an attempt to achieve more efficient designs, the technological frontier is pushed further and further. Every year science probes for a better understanding of natural phenomena, discovering new and improved methods to perform the same task more efficiently and with better results. One of the new technologies is the nonlinear analysis of structural systems using inelastic post-buckling member performance. Inelastic post-buckling member performance is defined as the constitutive relationship between axial load and displacement after the ultimate member capacity has been exceeded. A nonlinear analysis is able to predict the failure behavior of a structural system under ultimate loads …

Modeling Techniques For Water Supply Forecasting In The Western United States, David Charles Garen

Dissertations and Theses

Water supply forecasting in the western United States is the prediction of the volume of water passing a given point on a stream during the primary snowmelt runoff season. Most water supply forecasts are produced from multiple linear regression models using snowpack, precipitation, and streamflow measurements as independent variables. In recent years, conceptual watershed simulation models, typically using a time step of one day, have also been used to produce these forecasts.

This study examines model usage for: water supply forecasting in the West and has three specific purposes. The first is to examine the traditional usage of multiple linear …

Parameter Uncertainty And Modeling Of Sludge Dewatering In One Dimension, Joseph H. Plaskett

Dissertations and Theses

Separation of liquid from solids is a necessary step in the ultimate disposal of wastewater sludges. Most commonly, sludges are dewatered by pressure-filtration methods. Mathematical models of the physics of the sludge dewatering process would provide the ability to predict dewatering performance and optimize the design and operation of dewatering facilities.

Limits Of Limit Equilibrium And Finite Element Techniques Applied To Cracked Debris Dams On Collapsing Foundations, Stanley Soliday Jr.

Dissertations and Theses

Limits of slope stability, limit equilibrium methods, and of the finite element code FEADAM are reached in the application of these methods to the problem of cracked dams constructed on collapsing soils.

Utilizing a generic dam, various classic slope stability approaches are tested as possible dam slope failure mechanisms. Slope stability methods are rejected as a way to accurately define and quantify the collapse problem. As a result of this work a block rotation mode of collapse is postulated. Then the finite element method (FEM) is used to try to define and quantify the collapse problem. The FEM is applied …

Stochastic Hydrologic Modeling In Real Time Using A Deterministic Model (Streamflow Synthesis And Reservoir Regulation Model), Time Series Model, And Kalman Filter, Philip Kwok Fan Tang

Dissertations and Theses

The basic concepts of hydrologic forecasting using the Streamflow Synthesis And Reservoir Regulation Model of the U.S. Army Corps of Engineers, auto-regressive-moving-average time series models (including Greens' functions, inverse functions, auto covariance Functions, and model estimation algorithm), and the Kalman filter (including state space modeling, system uncertainty, and filter algorithm), were explored. A computational experiment was conducted in which the Kalman filter was applied to update Mehama local basin model (Mehama is a 227 sq. miles watershed located on the North Santiam River near Salem, Oregon.), a typical SSARR basin model, to streamflow measurements as they became available in simulated …

Green's Law Revisited: Tidal Long-Wave Propagation In Channels With Strong Topography, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Green's Law states that tidal long-wave elevation ζ and tidal transport Q vary with width b and depth h according to ζ ≌ b^−1/2h^−1/4 and Q ≌ b^+1/2h^+/4. This solution is of limited utility because it is restricted to inviscid, infinitesimal waves in channels with no mean flow and weak topography (those with topographic scale L ≫ wavelength λ). An analytical perturbation model including finite-amplitude effects, river flow, and tidal flats has been used to show that (1) wave behavior to lowest order is a function of only two nondimensional parameters representing, respectively, …

Evaluating The Role Of Geogrids In The Rehabilitation Of Cracked Dams Via Numerical Techniques, Kelly Dean Uhacz

Dissertations and Theses

Collapse and cracking of debris earth embankment dams is a serious problem in areas of the arid Western United States. The use of geogrids is evaluated in this thesis as a possible solution to prevent or reduce the amount of damage to the structures from collapse and cracking.

An apparatus was designed, constructed, and instrumented to electronically acquire data to evaluate the behavior of geogrids during pullout tests under various normal stresses. The pullout tests were also modelled using numerical techniques to correlate physical test data with numerical test data. Understanding the behavior of the geogrid, in both the physical …

Density Currents In Circular Wastewater Treatment Tanks, David M. Laliberte

Dissertations and Theses

Deviations from ideal flow and settling occur in circular wastewater treatment tanks because of tank geometry, flow conditions, and density currents caused by variations in suspended solids concentration and temperature distributions. Thermally induced density currents were investigated in this study. Under winter, low flow conditions, measurements were made of vertical and radial temperature distributions in the circular chlorination tank at Lake Oswego, Or., and in the circular primary and secondary clarifiers at Bend, Or. Thermistor arrays were used to collect the data which exhibited both vertically well-mixed and a two-layer flow regime. Inlet geometry and suspended solids in the secondary …

Gis Address-Matching And Transportation Analysis, James D. Orrell

Dissertations and Theses

Geographic Information System (GIS) address-matching combined with other GIS processing offers new analytical opportunities in the area of transportation planning and analysis. Address-matching, an automated method for generating geographically-referenced (geocoded) point locations on a map from common tabular databases, can facilitate transportation analysis by providing a planning tool based on individual rather than aggregated spatial distributions more common to transportation issues.

This thesis presents a case study in which GIS address-matching was I applied to a transportation problem at Oregon Health Sciences University (OHSU) in Portland, Oregon. The transportation problem at OHSU is common to major employment centers in urban …

Residual Circulation In Shallow Estuaries 1. Highly Stratified, Narrow Estuaries, David A. Jay, J. Dungan Smith

Civil and Environmental Engineering Faculty Publications and Presentations

Long-wave theory and simple turbulence closures have been used to show that three distinct types of circulation (highly stratified, weakly stratified, and partially mixed) arise in narrow, shallow estuaries from the finite amplitude of the tide and the interaction of stratification with vertical mixing. Each type has a different dominant process causing the vertical exchange of salt and fresh water on the flood, and each gives rise to a characteristic residual circulation. The tidal circulation in highly stratified shallow estuaries, described herein, is the result of a finite amplitude internal motion driven by the barotropic tide; shear instabilities at the …

Residual Circulation In Shallow Estuaries 2. Weakly Stratified And Partially Mixed, Narrow Estuaries, David A. Jay, J. Dungan Smith

Civil and Environmental Engineering Faculty Publications and Presentations

Long-wave theory is used herein to analyze circulation in weakly stratified and partially mixed estuaries. Unlike the highly stratified systems considered in part 1, the flows considered here have only a minimal tidal-frequency internal wave component. These estuaries may therefore be modeled as the sum of weakly interacting barotropic and baroclinic modes. The dominant factors driving the residual flow are finite amplitude barotropic effects in weakly stratified estuaries and a combination of barotropic effects and steady horizontal density gradient forcing in partially mixed estuaries. The dominant vertical exchange mechanism in the weakly stratified case is bottom boundary-induced turbulence, and that …

Hyperbolic Soil Parameters For Granular Soils Derived From Pressuremeter Tests For Finite Element Programs, Dieter Neumann

Dissertations and Theses

In the discipline of geotechnical Engineering the majority of finite element program users is familiar with the hyperbolic soil model. The input parameters are commonly obtained from a series of triaxial tests. For cohesionless soils however, today's sampling techniques fail to provide undisturbed soil specimen. Furthermore, routine triaxial tests can not be carried out on soils with grains exceeding 10 - 15 mm in size.

Initial developments towards a link between high quality pressuremeter tests and the hyperbolic finite parameters element input are presented. Theoretical and empirical approaches are used to determine the entire set of and from pressuremeter tests. …

A Finite Difference Soil-Structure Interaction Study Of A Section Of The Bonneville Navigation Lock Buttress Diaphragm Wall Utilizing Pressuremeter Test Results, Thomas C. Mccormack

Dissertations and Theses

The P-y curve, used in current practice as an efficient Iine-load vs. soil displacement model for input into the finite difference method of laterally loaded pile analysis, is extended in this study for use with cohesionless soils in diaphragm wall analysis on the Personal Computer with the BMCOL7 program. An analogous W-y curve is proposed, an elastic-plastic model with line-load limits developed from classical earth-pressure theories.

A new formula for predicting a horizontal wall modulus for cohesionless soils from the pressuremeter modulus is developed for use in predicting the displacements on the W-y curves. The resulting modulus values are shown …

Elastic-Plastic Analysis Of Axisymmetrically Loaded Isotropic Circular And Annular Plates Undergoing Large Deflections, Aiman Raji Akileh

Dissertations and Theses

The concept of load analogy is used in the elastic and elastic-plastic analysis of isotropic circular and annular plates undergoing moderately large deflection. The effects of the nonlinear terms of lateral displacement and the plastic strains are considered as additional fictitious lateral loads, edge moments, and in-plane forces acting on the plate. The solution of an elastic or elastic-plastic Von Karman type plate is hence reduced to a set of two equivalent elastic plate problems with small displacements, namely, a plane problem in elasticity and a linear elastic plate bending problem. The method of finite element is employed to solve …

Analysis And Prediction Of The Water Temperature Of The Mckenzie River, Oregon Using The Equilibrium Temperature Approach, R. Peder Hansen

Dissertations and Theses

A one dimensional, steady flow, unsteady temperature model is used to evaluate the effects of two U.S. Army Corps of Engineers (COE) dams and resulting reservoirs on hourly water temperatures of the mainstem McKenzie River from Delta Park (RM 62.1) to Leaburg Dam (RM 38.8). Both COE projects are on tributaries to the McKenzie River and at present have only bottom withdrawl capabilities.

Water temperatures were simulated using the equilibrium temperature approach with air temperature used to estimate equilibrium temperature and also using computed hourly equilibrium temperature. Results obtained using computed equilibrium temperatures were less satisfactory than results using air …

Post-Buckled Performance Of Partially Restrained And Intermediately Supported Steel Angles, Perumal Radhakrishnan

Dissertations and Theses

The post-buckled performance of cross-braced single angles was experimentally determined. The results of this study will be used by the Bonneville Power Administration for the analysis of member performance in transmission towers.

Forecasting For Local Water Management, Douglas Alan Putnam

Dissertations and Theses

Forecast models are investigated and developed for use in local water management to aid in determining short term water requirements and availability. The forecast models include precipitation occurrence and depth using a Markov chain model, temperature and solar radiation with a multivariate autoregressive model, and streamflow with autoregressive-moving average models. The precipitation, temperature, and solar radiation forecasts are used with a soil moisture model to determine water demands. A state space approach to the Muskingum-Cunge streamflow routing technique is developed. The forecast water demands and streamflow forecasts are used as inputs to this routing model. Forecast model errors and propagation …

The Applicability Of Microcomputers To Local Water Management, Roderick Lee Allen

Dissertations and Theses

Historically, hydrologic models have been available only on mainframe computers and have therefore not been used by local water managers to support daily decisions. The development of the microcomputer presents an opportunity for that to change.

Mathematical models of soil moisture and river routing are selected, developed and tested for use on a microcomputer as an aid to local water management. The models are then integrated with an appropriate data base in a computer program written for a microcomputer. The result is a Decision Support System for local water managers.

In order to evaluate the feasibility of using the Decision …

Transient Flow Inverse Study Calculation Of Unsaturated Permeability Of Wood, Farid Piroozmandi

Dissertations and Theses

One of the major processes in lumber industry is wood drying. This process consumes large amounts of energy and capital, and due to the length of time it takes, it acts as a governing factor in lumber production levels. Development of improvements in processes and equipment used in wood drying can be expedited through computer simulation of various drying procedures. These numerical simulations depend on the accuracy of numerical models representing wood transport properties, including functional dependency of liquid permeability through wood with respect to local saturation level. Data available in the literature mainly represent wood permeability properties at fully …

The Dynamics Of The Columbia River Estuarine Ecosystem: Volume I And Volume Ii, Creddp, Charles A. Simenstad, David A. Jay, C. David Mcintire, Willa Nehlsen, Christopher R. Sherwood, Lawrence F. Small

Civil and Environmental Engineering Faculty Publications and Presentations

Integrates results from the CREDDP studies into a comprehensive synthesis. Includes physical setting and processes; relationships between physical and biological processes and among functional groups of organisms; species, biomass and productivity per habitat type per region. Approximately 360 pages per volume.

Circulatory Processes In The Columbia River Estuary, David A. Jay

Civil and Environmental Engineering Faculty Publications and Presentations

Covers tidal circulation, density distribution, vertical mixing, salt transport, and low-frequency flow processes, with contributions to estuarine circulation theory.

State Space Approach To Flood Stage Estimation, Gregory Allen Jones

Dissertations and Theses

A flood routing and stage prediction model is developed using the techniques of State Space and Kalman filtering. The governing equation is the physically based hydrologic method of flood routing with the output being an optimal estimate of stage given known inputs of streamflow. These equations are developed in state space and the Kalman filter is employed to estimate the flow and river stage.

The model is applied to the Toutle and Cowlitz Rivers in the State of Washington, where the stage is affected by a shifting bed elevation. With the deterministic inputs at Mayfield Dam on the Cowlitz and …

A Numerical Solution For Three Dimensional Beam Columns In The Elastic Region, Hamid Reza Afghan

Dissertations and Theses

The three differential equations describing the behavior of the beam columns in three dimensions are derived and presented in finite difference form. A computer model is developed to solve the simultaneous equations in the elastic regions and predict the member behavior.

The computer program is checked by comparing the results obtained from the program with data from other investigators, and classical analytical techniques.

Analytical And Experimental Stresses In Concrete Pavements And Unbonded Overlays, Ahmad Jaber

Dissertations and Theses

The principal objective of this study is to determine the accuracy of calculating stresses in concrete pavements and unbonded overlays under different loading conditions. The computed stresses for the single layer pavements are obtained based on Westergaard theory, the finite-element model (ILLI-SLAB), and the elastic layered model (ELSYM5). For the two-layer unbonded systems, stresses are estimated based on the finite-element theory and the Portland Cement Association design method. The experimental results for the comparison were available from a series of tests done on model scale concrete pavements and unbonded overlays. The results of present investigation show that the computed stresses …

A Study Of Single Angle Compression Members, James Robert Callaway

Dissertations and Theses

A study was undertaken to investigate the compressive capacity of a specific group of single angle members.

A review of existing literature and techniques was presented. Laboratory compression tests were performed on 22 angle members of four different sizes and two different lengths. Additional tests were performed to determine the yield strength of the material. The results, normalized with respect to the yield stress, were tabulated and discussed.

Two existing analytic models were used to attempt to predict the ultimate capacity of the test members. The first, an elastic method, was based upon the AISC combined stress equation. The second, …

Secondary Stresses In Bowstring Timber Trusses, John F. Bradford

Dissertations and Theses

This study was undertaken in order to determine analytically the magnitude of the secondary (i.e., joint deflection induced) moments in the continuous glued-laminated chords of bowstring timber trusses. Traditionally, these moments have been assumed to be small and therefore neglected. The American Institute of Timber Construction makes no mention of these moments in their recommended design procedure.