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Tmdls: Statistical Correlations Or Mechanistic Modeling?, Scott A. Wells, Thomas M. Cole

Civil and Environmental Engineering Faculty Publications and Presentations

In developing TMDL waste-load allocations for the Snake River-Reservoir system in Western Idaho and Eastern Oregon, determinations of the assimilative capacity of the system and the impact of pollutant reduction strategies has been performed using both a statistical-correlation approach and a mechanistic modeling approach. The system included the Lower Snake River, Brownlee Reservoir, Oxbow Reservoir, and Hells Canyon Reservoir with the focus was on Brownlee Reservoir.

The statistical approach used on Brownlee Reservoir divided the system into riverine and lacustrine zones. Field data were then averaged over season and location to provide statistical correlations, such as between total phosphorus (TP) …

Compression Tests Of Cold-Reduced High Strength Steel Long Columns, Demao Yang, Gregory J. Hancock, Kim J. R. Rasmussen

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

This paper describes a series of compression tests performed on long columns fabricated from cold-formed high strength steel plates with nominal yield stress of 550 MPa (80 ksi). The steel is classified as G550 to Australia Standard AS1397. The test results presented in this paper are the second stage of an Australian Research Council research project entitled "Compression Stability of High Strength Steel Sections with Low Strain-Hardening". A total of 28 long columns, which were made from two thicknesses of sheet steel (0.42 mm and 0.6 mm) (0.017 in. and 0.024 in.), were tested. A box shaped section was tested …

Some Improvements To The Design Of Sandwich Panels Subject To Local Buckling Effects, Narayan Pokharel, Mahen Mahendran

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

Past research into the local buckling behaviour of fully profiled sandwich panels has been based on polyurethane foams and lower grade steels, and not for very slender plates. The Australian sandwich panels use polystyrene foam and thinner (0.42 mm) and high strength steels (G550 with a minimum yield stress of 550 MPa), which are bonded together using separate adhesives. Therefore a research project on Australian sandwich panels was undertaken using experimental and finite element analyses. The experimental study on 50 foam-supported plate elements and associated finite element analyses produced a large database for sandwich panels subject to local buckling effects, …

Adaptive Nonlinear Finite Element Analyses Of High Strength Steel Cladding Systems, M. Duan, Mahen Mahendran

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

In this paper, an adaptive nonlinear finite element method was developed and applied to the ultimate strength analysis of light gauge high strength steel cladding. Effect of mesh refinement on the solution accuracy was investigated for the nonlinear analysis of steel cladding systems under wind uplift loading. A comparison of numerical solutions was made with experimental results and a good agreement is shown using the adaptive finite element method. A parametric study was also conducted to investigate the factors that affect the ultimate strength behavior of high strength steel cladding systems. This paper presents the details of this study and …

Behaviour Of Cold-Formed Thin-Walled Steel Short Columns With Service Holes At Elevated Temperatures, M. Feng, Y. C. Wang, J. Michael Davies

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

This paper presents the results of an experimental and numerical investigation into the axial strength of cold-formed thin-walled lipped channel sections with service holes under ambient and uniform high temperature conditions. Short columns of two different thickness with service holes under different temperatures have been tested, and analysed by using a variety of design methods and a commercial finite element program ABAQUS (1998). Three design methods (the British Standard BS5950 Part 5 (1987), Eurocode 3 Part 1.3 (CEN 1996) and the American Specification AISI (1996)) have been used in this paper. In the finite element analysis, both geometrical and material …

Design Of Industrial Storage Racks, Andrew T. Sarawit, Teoman Pekoz

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

Design of industrial steel storage racks is complex due to the presence of significant perforations in the columns and the semi-rigid nature of column bases and beam to column connections. Many assumptions are made in the current design provisions to simplify the design but as a result the design becomes rather conservative. Studies were conducted at both the component and global scale to address some of these assumptions. At the component level, the topics focused upon are the column bases, beam to column connections, and members. Results indicate that improvements in the current design procedures are possible and recommendations for …

Moisture Migration In Concrete Slabs During Drying, Niall Holmes, Roger West

Conference papers

This paper presents the profiles of relative humidity (RH) readings taken at various depths in concrete slabs during a time period of over 230 days using probes attached to a humidity-reading device. It also examines the effect ambient conditions have on the drying process. For the experimental work, two sets of slabs were tested, one in a controlled environment with an elevated temperature and the other in a laboratory at room temperatures. It was found, not surprisingly that the slabs in the controlled room appeared to dry out at a much faster rate than those held at room temperature. However, …

Probability Of A Hazardous Material Truck Accident In New Jersey, Mahesh Damodaran

Theses

Accident prediction modeling is a powerful tool for determining the frequency of accidents under certain circumstances. Nationwide, direct damages from highway hazardous material spills for the year 2000 were tallied at over $31billion. This thesis determines the probability of an accident involving hazardous materials on the roads of New Jersey. The methodology is based on a British predictive equation used by their Highways Agency to determine the probability of a hazardous spill over a section of a roadway. The parameters used by the British's Highways Agency, which is obtained from their accident data, were modified to reflect conditions that best …

Field Guide To The Geology Of The Harlan County Lake Area, Harlan County, Nebraska, With A History Of Events Leading To Construction Of Harlan County Dam, Robert F. Diffendal Jr., Duane R. Mohlman, R. George Corner, F. Edwin Harvey, K. J. Warren, Scott Summerside, Roger K. Pabian, Duane A. Eversoll

School of Natural Resources: Faculty Publications

The year 2002 will mark the fiftieth anniversary of completion of the Harlan County Dam and Multi-Purpose Reservoir. This seems a good time to write about the history of and reasons for building the dam, the effects of the dam and reservoir on the Republican River valley, and the geologic features seen along the shores of the lake and areas nearby. As many junior authors helped produced this educational circular, they are listed in the table of contents. All other sections were written by the senior author.

Includes July 2016 update: Addendum of photographs showing fault traces on drought-exposed lake …

Forensics And Case Studies In Civil Engineering Education: State Of The Art, Norbert J. Delatte, Kevin L. Rens

Civil and Environmental Engineering Faculty Publications

This paper reviews the state of the art in the use of forensic engineering and failure case studies in civil engineering education. The study of engineering failures can offer students valuable insights into associated technical, ethical, and professional issues. Lessons learned from failures have substantially affected civil engineering practice. For the student, study of these cases can help place design and analysis procedures into historical context and reinforce the necessity of lifelong learning. Three approaches for bringing forensics and failure case studies into the civil engineering curriculum are discussed in this paper. These are stand-alone forensic engineering or failure case …

Amis: Least Cost Path Analysis For Transportation Planning, Joel Brumm, Ted H. Grossardt, Keiron Bailey

Kentucky Transportation Center Faculty and Researcher Publications

The State requested a GIS-based route planning tool. More than 50 raster data layers were assembled within ArcView 3.2, encompassing a full spectrum of demographic, physical, and cultural features. These data layers were given a numerical rating using multicriteria decision making software and input from professionals from a variety of fields. The multicriteria decision making software then set the relative importance of these surface features as impediments or attractors, creating a travel-cost surface. This synthesis of technologies, combined in a tool termed AMIS (Analytic Minimum Impedance Surface), found the least-cost path to any point within the study area.

Creep And Creep-Recovery Models For Wood Under High Stress Levels, Zhiyong Cai, Kenneth J. Fridley, Michael O. Hunt, David V. Rosowsky

Civil and Environmental Engineering and Construction Faculty Research

Forty small clear southern pine specimens were loaded under third-point bending to examine creep and creep-recovery behavior for wood under high stress levels. Stress levels of between 69% and 91% of the predicted static strength were applied for 23 h with 1 h allowed for recovery, and the resulting deflection vs. time behavior was studied. The experimental creep and creep-recovery behavior was modeled using modified power law functions. The results indicate that these functions provide the best fit to both primary and secondary experimental data. The empirical models can be used to simulate the viscoelastic behavior of wood under high …

Fuzzy-Art Neural Networks For Predicting Chi-Chi Earthquake Induced Liquefaction In Yuan-Lin Area, S. G. Chern, R. F. Hu, Y. J. Chang, I. F. Tsai

Journal of Marine Science and Technology–Taiwan

In this study, a fuzzy adaptive network “Fuzz-ART”, based on adaptive resonance theory (ART) combined with fuzzy set theory is developed to evaluate liquefaction potentials induced by Chi-Chi earthquake in Yuan-Lin area. The proposed system combines the backpropagation algorithm for parameter learning and the fuzzy ART algorithm for structure learning. With the help of case studies, it is shown that the “Fuzz-ART” network is able to predict liquefaction potentials much more satisfactorily than conventional artificial neural network methods. If more data are collected, it may well evaluate liquefaction potentials induced by Chi-Chi earthquake.

A Stability Criterion Of Time-Delay Fuzzy Systems, Cheng-Wu Chen, Wei-Ling Chiang, Ken Yeh, Zhen-Yuan Chen, Li-Teh Lu

Journal of Marine Science and Technology–Taiwan

To guarantee the asymptotic stability, a stability criterion in terms of Lyapunov's direct method for multiple time-delay fuzzy interconnected systems is proposed in this paper. Each of these systems consists of a number of subsystems represented by TakagiSugeno fuzzy models with multiple time delays.

Drbem Analysis Of Combined Wave Refraction And Diffraction In The Oresence Of Current, Sung-Shan Hsiao, Ming-Chung Lin, Nien-Chia Hu

Journal of Marine Science and Technology–Taiwan

A more effective numerical model using the dual reciprocity boundary element method (DRBEM) is presented to study the combined effects of wave refraction- diffraction and currents. The mildslope equation with current effects is reformulated to an inhomogeneous Helmholtz equation. Applying the conventional boundary element method to this inhomogeneous equation, the inhomogeneous part will result in a domain integral which makes the computation complicated and messy. To improve this drawback, the DRBEM is adopted to transform the domain integral to boundary integral. In order to verify the validity of this model, the relative amplitudes around a circular island without current effects …

Long-Term Benefits Of Stabilizing Soil Subgrades, Tommy C. Hopkins, Tony L. Beckham, Liecheng Sun, Bixian Ni, Barry Butcher

Kentucky Transportation Center Research Report

Chemical admixtures have been used extensively since the mid-eighties in Kentucky to improve bearing strengths of soil subgrades. Most pavements in Kentucky are constructed on clayey soils. Although short-term observations at a small number of sites showed that chemical stabilization worked very well, a need existed to perform a more comprehensive review and to assess the long-term benefits of this subgrade stabilization method. The main intent of this study was an attempt to address questions concerning bearing strengths, longevity, durability, structural credit, economics, and performance of pavements resting on soil subgrades mixed with chemical admixtures. In-depth field and laboratory studies …

A Model For Optimizing The Selection Of Project Delivery Systems Using Analytic Hierarchy Process (Ahp), Arosha De Silva

Masters Theses

The project delivery systems applicable to the construction industry in the U.S. consist of different approaches. This study focuses on three main approaches, (1) Design-Bid-Build (DBB), (2) Design-Build (DB), and (3) Construction Management (CM). Since each construction project is unique, selecting the right project delivery system is a tough decision.

This study develops a decision making system, based on the Analytic Hierarchy Process (AHP), for selecting the best delivery system for a given construction project. AHP is a decision making mathematical model developed by Thomas L. Saaty and consists of a hierarchical structure. It analyzes several alternatives for a given …

Bi-Axially Loaded Slender Reinforced Concrete Columns Subjected To Sustained Loads, Song Gu

Dissertations

A generalized analytical approach is presented in this research to predict the behavior both of slender and short reinforced concrete columns under sustained biaxial eccentric load.

The present analysis proposes equations established at a cross section of a reinforced concrete column by combining force equilibrium, constitutive law, and compatibility conditions. The strain and curvature of each section and the deflection of the column can then be obtained and resolved.

The established creep computation models, recommended separately by American Concrete Institute (ACI) 209R-92 and the Comite' Euro-International du Be'ton (CEB)-FIP 1990 Model Code have been used to calculate creep and shrinkage …

A Bi-Level Programming Approach For The Shipper-Carrier Network Problem, Ya Wang

Dissertations

The Stackelberg game betweenshippers and carriers in an intermodal network is formulated as a bi-levelprogram. In this network, shippers make production, consumption, androuting decisions while carriers make pricing and routing decisions.The oligopolistic carrier pricing and routing problem, which comprisesthe upper level of the bi-level program, is formulated either as a nonlinearconstrained optimization problem or as a variational inequality problem,depending on whether the oligopolistic carriers choose to collude orcompete with each other in their pricing decision. The shippers' decisionbehavior is defined by the spatial price equilibrium principle. Forthe spatial price equilibrium problem, which is the lower level of thebi-level program, a …

Impact Of Truck Regulation And 65mph Speed Limit On Truck Accidents In New Jersey, Rajat G. Rajbhandari

Theses

The state of New Jersey enacted two regulations with significant importance to the highway operations: 65 mph speed limit and truck restriction on the National Network. The speed limit of 65mph was used on limited sections of interstate system highways with an objective to reduce energy consumption by vehicles and truck restriction was used on the interstate system and other state highway system to reduce large truck accidents and thereby increase truck safety. In this research, the safety impacts of these two regulations on truck crashes were studied.

The research focused on monthly truck crashes along the highway sections where …

Overhang Effects On End-One-Flange Web Crippling Capacity Of Cold-Formed Steel Members, Michael W. Holesapple, Roger A. Laboube

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Coalbed Methane In The San Juan Basin Of Colorado And New Mexico, Catherine Cullicott, Carolyn Dunmire, Jerry Brown, Chris Calwell

Coalbed Methane Development in the Intermountain West (April 4-5)

35 pages (includes color illustrations and maps).

Contains 6 pages of endnotes.

Coalbed Methane Development In Wyoming’S Powder River Basin, Diana Hulme

Coalbed Methane Development in the Intermountain West (April 4-5)

21 pages (includes color illustrations and maps).

Contains endnotes.

Powder River Basin Coalbed Methane Financial Model (Prb-Cbm-Fm), W. Thomas Goerold

Coalbed Methane Development in the Intermountain West (April 4-5)

12 pages (includes illustrations).

Contains references.

Overview Of Cbm Issues In The San Juan Basin, Catherine Cullicott

Coalbed Methane Development in the Intermountain West (April 4-5)

3 pages (includes some color illustrations and maps).

Impacts Of Cbm Development On Communities, Gwen Lachelt

Coalbed Methane Development in the Intermountain West (April 4-5)

2 pages.

Agenda: Coalbed Methane Development In The Intermountain West, University Of Colorado Boulder. Natural Resources Law Center

Coalbed Methane Development in the Intermountain West (April 4-5)

306 p. : ill., maps ; 28 cm

"July 2002"--Cover

Proceedings of a conference held April 4-5, 2002

Listed as no. 28 in the Research Report Series on the NRLC Recent Publications list

Includes bibliographical references

Contents:

Coalbed methane development in the Intermountain West : a primer / Gary Bryner -- Coalbed methane development in the Intermountain West : case studies. Coalbed methane in the San Juan Basin of Colorado and New Mexico / Catherine Cullicott, Carolyn Dunmire, Jerry Brown, Chris Calwell ; Coalbed methane development in Wyoming's Powder River Basin / Diana Hulme -- Keynote address / Rebecca Watson …

The Hydrology Of Coalbed Methane Reservoirs And The Interplay Of Gas, Water, And Coal In Cbm Production, Leslie Nogaret

Coalbed Methane Development in the Intermountain West (April 4-5)

7 pages (includes color illustrations and map).

Best Cbm D[R]Illing, Completion, Production, Technologies, And Management Practices, Dennis Carlton

Coalbed Methane Development in the Intermountain West (April 4-5)

3 pages.

Cbm Development And Water Issues, Dave Brown

Coalbed Methane Development in the Intermountain West (April 4-5)

7 pages (includes color illustrations).