Engineering Commons^™

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 …

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.

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.

The Effect Of Residual Stress Distribution On The Ultimate Strength Of Tubular Beam-Columns, Steven L. Barrett

Dissertations and Theses

Using data for the longitudinal residual stress distribution in welded steel tubes, curves describing these distributions are selected for study. Each of these curves are checked for static balance across the tube cross section. The curves that exhibit an imbalance are adjusted by a combination of a simplified model for each and the use of a computer program that is developed to calculate the resulting forces and moments on the cross section. The residual stress in the area of the tube wall opposite the longitudinal weld is found to be the most important in the adjustment to obtain exact equilibrium. …

Photogrammetric Digitizing System, Frank Richard Gorshe

Dissertations and Theses

The acquisition of terrain data from aerial photography using digital photogrammetric methods gives the engineer and planner an economical alternative to conventional ground surveys. This paper describes a complete photogrammetric digitizing system developed for the Portland District Army Corps of Engineers. The hardware of the system consists of a

Wild AlO first order stereoplotter interfaced to an Altec AC-74 coordinate digitizer which is interfaced to both a Hewlett Packard 9810A programmable calculator and a Digi-Data nine-track magnetic tape recorder. The software of the system consists of photogrammetric routines developed for online computation by the programmable calculator and a sophisticated FORTRAN …

Response Of Orthotropic Bridge Decks To Highway Loadings, Harry Morris Rexin

Dissertations and Theses

This thesis documents the fabrication, testing techniques, and response of a plastic scale model of an orthotropic bridge deck. To economically investigate a two-lane steel bridge deck, plastic Acrylic^R was used as a modeling material. Welds were simulated with dichloromethane, a capillary action solvent, and PS-30, a polymerizable cement. Deflections were measured with laboratory dial guages while strains were monitored with strain guages mounted on the deck.

The response of the deck to AASHO vehicle axle loads was compared with a discrete element computer program used to analyze orthotropic bridge decks continuous over flexible supports. Results indicate good correlation …