Civil and Environmental Engineering Commons^™

A Stabilized Rbf Collocation Scheme For Neumann Type Boundary Value Problems, Nicolas Ali Libre, Arezoo Emdadi, Edward J. Kansa, Mohammad Rahimian, Mohammad Shekarchi

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The numerical solution of partial differential equations (PDEs) with Neumann boundary conditions (BCs) resulted from strong form collocation scheme are typically much poorer in accuracy compared to those with pure Dirichlet BCs. In this paper, we show numerically that the reason of the reduced accuracy is that Neumann BC requires the approximation of the spatial derivatives at Neumann boundaries which are significantly less accurate than approximation of main function. Therefore, we utilize boundary treatment schemes that based upon increasing the accuracy of spatial derivatives at boundaries. Increased accuracy of the spatial derivative approximation can be achieved by h-refmement reducing the …

Forecasting Model For Air Taxi, Commercial Airline, And Automobile Demand In The United States, Hojong Baik, Antonio A. Trani, Nicolas Hinze, Howard Swingle, Senanu Ashiabor, Anand Seshadri

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A nationwide model predicts the annual county-to-county person roundtrips for air taxi, commercial airline, and automobile at 1-year intervals through 2030. the transportation systems analysis model (TSAM) uses the four-step transportation systems modeling process to calculate trip generation, trip distribution, and mode choice for each county origin-destination pair. Network assignment is formulated for commercial airline and air taxi demand. TSAM classifies trip rates by trip purpose, household income group, and type of metropolitan statistical area from which the round-trip started. a graphical user interface with geographic information systems capability is included in the model. Potential applications of the model are …

A Laboratory Study Of Struvite Precipitation For Phosphorus Removal From Concentrated Animal Feeding Operation Wastewater, Sushmita Dhakal

Masters Theses

"Struvite precipitation occurs spontaneously in many wastewater treatment facilities as a nuisance. However, struvite precipitation is now being studied as a method to concurrently treat high phosphorus wastewaters and generate a valuable product. Many factors influence the precipitation of struvite such as component -ion molar ratios, pH, aeration, solubility, solids and mixing energy. In the present work, struvite precipitation in the actual swine wastewater was studied by strategically controlling aeration, pH, and mixing"--Abstract, page iv.

Hazards Assessment Of St. Charles County - Earthquakes And Floods, Amy Lynn Krauch

Masters Theses

"Located on the northernmost limits of the St. Louis metropolitan area, St. Charles County has been, and continues to be, one of the fastest-growing counties in the country. The county consists of several major cities featuring extensive industry, retail, and agriculture. Bounded by the Missouri River on the south and the Mississippi River on the north and east, St. Charles County is predominantly flat, low-lying terrain at great risk to periodic flooding. The county is also well within the area of influence for several local seismic zones, increasing the susceptibility to earthquake damage. Given the apparent risk to both flood …

Electromagnetic Modeling Of Distributed Coaxial Cable Crack Sensors In Reinforced Concrete Members, Mei Wang

Masters Theses

"Distributed crack sensors were recently developed with coaxial cables that are composed of inner and outer conductors as well as dielectric layer in between. These sensors were designed based on the change in topology of the cable outer conductor structure under strain effects. Various tests of reinforced concrete (RC) beams and columns indicated that the newly designed sensors are 10~50 times more sensitive than commercial cables to the longitudinal elongation applied on their cable structures. The spatial resolution of the sensors is approximately 50 mm. Limited numerical simulations with the transmission line theory and the finite difference time domain model …

Performance Of Fire-Damaged Prestressed Concrete Bridges, Wendy Leann Moore

Masters Theses

"The purpose of this experimental program was to develop and analyze the effects of fire damage on prestressed concrete bridges. Flexural strength and serviceability of the bridge were measured by inputting fire damaged data into a parametric study spreadsheet consisting of a typical 3-span continuous prestressed concrete bridge. Data was obtained by exposing two types of specimens to different levels of elevated temperatures and then cooling them at room temperature to simulate fire damage. The two specimen types were prestressing strands which were tested in tension and concrete blocks with a single prestressing strand embedded in the center, which were …

Laboratory Analysis Of Small Strain Moduli In Compacted Silts, David M. Weidinger

Masters Theses

"Soil compaction quality control accounts for a significant portion of geotechnical practice. Often the performance of a roadway can be directly linked to the quality of the compacted subgrade. A poor subgrade can result in weak areas in the road causing excessive deflections at the surface, ultimately leading to a pot hole or uneven surface and an unpleasant ride for the travelers. Vehicles passing over a section of highway causes small strains in the founding soil. These strains accumulate over time. A better understanding of how the compacted soil responds at small strains could shed light on improving the quality …

Experimental Validation Of An Integrated Frp And Visco-Elastic Hardening, Damping, And Wave-Modulating System For Blast Resistance Enhancement Of Rc Columns, Brian Henry Wood

Masters Theses

"In today's society, terrorist attacks and accidental explosions pose a major threat to critical infrastructure. Vulnerable to blast loading, structures must be rehabilitated to ensure structural stability and protect human life. The goal of this study is to develop and validate a sandwich composite technology for column retrofitting. The new technology consists of an inner fiber reinforced polymer (FRP) sheet, an outer FRP sheet, and a visco-elastic (VE) layer sandwiched between the two FRP sheets. The inner FRP sheet is wrapped around an existing column for confinement, while the outer FRP sheet is for anchoring of the VE layer into …

Development Of A Gis-Based Seismic Hazard Screening Tool, Andrew J. Wilding

Masters Theses

"Geotechnical earthquake engineering hazards have consequences that are difficult to mitigate, especially for infrastructure systems with multiple and distributed components. In the last few decades significant progress has been made to provide more accurate and useful methods to evaluate hazards for complex systems. One of these advances involves the application of spatial analysis and geographic information systems (GIS), for not only presenting data as maps, but also providing more practical and usable solutions, such as calculating the hazard potential with spatial distribution. This thesis studies the evaluation of geotechnical earthquake engineering hazards within a GIS environment, using borehole-specific data and …

Behavior Of Full-Scale Rc T-Beams Strengthened In Shear With Externally Bonded Frp Sheets, Antonio Brancaccio

Masters Theses

"Shear deficiencies in many bridges may be considered even more critical than flexural deficiencies since shear failures occur without advance warning and are more catastrophic. Deficiencies in shear can be due to insufficient shear reinforcement, use of outdated design codes, a reduction in the steel area due to corrosion, or an increase in the service load due to change of occupancy for the structure.

In recent years, many research studies have investigated the shear behavior of reinforced concrete (RC) beams strengthened with fiber-reinforced polymer (FRP) composites, however, most of them were conducted on small-scale specimens. Thus, analytical models and design …

Modeling Kinetics Of Hydrolysis Of Three Pesticides In Laboratory Waters, Michelle Kim Marincel

Masters Theses

"Pesticides and pesticide degradates found in drinking water sources are of particular concern to human health. When treated and disinfected at a drinking water plant, pesticides etridiazole, metribuzin, and diazinon undergo many treatment processes including lime softening, where the water pH is raised to 10 for calcium removal or 11 for magnesium removal. This thesis focuses on modeling the kinetics of hydrolysis of three pesticides that have the potential to undergo hydrolysis in drinking water plants. Linearly and non-linearly regressed first order and non-linearly regressed second order models were applied to the experimental data and compared to limited literature values. …

Estimation Of Earthquake Loss Due To Bridge Damage In The St. Louis Metropolitan Area. Ii: Indirect Losses, David Lee Enke, Chakkaphan Tirasirichai, Ronaldo Luna

Engineering Management and Systems Engineering Faculty Research & Creative Works

An approach to estimate the indirect economic loss due to damaged bridges within the highway system from an earthquake event is presented. The indirect cost considered refers to the increased highway transportation cost only. The study zone covers the St. Louis metropolitan area and its surrounding suburban regions. An earthquake scenario centered in St. Louis, with a magnitude 7.0 is used. The direct earthquake loss was primarily damage to bridges, which causes an increase in travel time and distance within the transportation network. This information is then used as input for the indirect loss model. The indirect loss is examined …

Formation And Removal Of Pesticides And Pesticide Transformation Products During Water Treatment, Evelyn F. Chamberlain

Doctoral Dissertations

"A comprehensive suite of over 60 pesticides (herbicides, insecticides, and fungicides) representing a variety of classes at environmentally relevant concentrations (low µg/L) were screened for reactivity under typical drinking water conditions and dosages. The most common oxidants/transformation agents in water treatment systems were examined for reactivity including free and combined chlorine, chlorine dioxide, permanganate, ozone, hydrogen peroxide, ultraviolet radiation, and high pH (alkaline hydrolysis). Due to the broad nature of the study, pesticide compounds were analyzed as multiple mixes broken into two groups based on analytical methods, those analyzed by GC/ECD and those by LC/MS. Combinations of reactive disinfectant/oxidant and …

Physical Modeling Of Railroad Ballast Using The Parallel Gradation Scaling Technique Within The Cyclical Triaxial Framework, Adam F. Sevi

Doctoral Dissertations

"Due to the difficulties involved with testing large particle granular materials such as rockfill and railroad ballast, several methods of testing scaled down model specimens have been introduced. Of these techniques, the parallel gradation model has been found to be most useful. The parallel gradation model states that a smaller grainsize distribution model granular material, of the same composition as the prototype material, can be used in triaxial testing at a scaled down grainsize, if the model materials grainsize is exactly parallel to the prototype material. Therefore, a model granular material composed of a smaller, but parallel, grainsize distribution can …

Steel Sheet Sheathing Options For Cfs Framed Shear Wall Assemblies Providing Shear Resistance, Cheng Yu, Hitesh Vora, Tony Dainard, Jimmy Tucker, Pradeep Veetvkuri

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

The North American Standard for Cold-Formed Steel Framing - Lateral Design, AISI S213-07, provides design provisions for cold-formed steel framed shear walls with steel sheet sheathing. However, options are limited to 18-mil and 27-mil steel sheet sheathing. Presented in this report are the findings from an extensive monotonic and cyclic testing program conducted at the University of North Texas of 30-mil and 33-mil steel sheet sheathed shear walls with 2:1 and 4:1 aspect ratios and 27-mil sheet steel shear walls with 2:1 aspect ratio and 6-in., 4-in., 3-in., and 2-in. fastener spacing at panel edges. It is anticipated that the …

North American Standard For Cold-Formed Steel Framing -- Floor And Roof System Design, 2007 Edition (Reaffirmed 2012), American Iron And Steel Institute

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

No abstract provided.

Cold-Formed Steel Framing Design Guide, Second Edition, American Iron And Steel Institute

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

This Design Guide has been developed under the direction of the American Iron and Steel Institute Committee on Specifications for the Design of Cold-Formed Steel Structural Members. The development of the Guide was sponsored by the American Iron and Steel Institute and the Steel Stud Manufacturers Association. The AISI Committee on Specifications wishes to acknowledge and express gratitude to Mr. Thomas Trestain of T. W. J. Trestain Structural Engineering who was the author of this Guide.

With anticipated improvements in understanding of the behavior of cold-formed steel and the continuing development of new technology, this material might become dated. It …

North American Standard For Cold-Formed Steel Framing -- Wall Stud Design, 2007 Edition (Reaffirmed 2012), American Iron And Steel Institute

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

No abstract provided.

Steel Sheet Sheathing Options For Cfs Framed Shear Wall Aseemblies Providing Shear Resistance, Cheng Yu, Hitesh Vora, Tony Dainard, Pradeep Veetvkuri

CCFSS Library (1939 - present)

In cold-formed steel construction, stud walls covered with steel sheet sheathing is an available option to resist lateral loads such as those caused by wind and earthquakes. The current American Iron and Steel Institute (AISI) Standard for Cold-Formed Steel Framing - Lateral Design 2004 Edition provides nominal shear strength for a limited range of steel sheet sheathed shear wall configurations. This report presents a research project developed to add values for 0.030-in. and 0.033-in. steel sheet sheathed shear walls with 2:1 and 4:1 aspect ratios and 0.027-in. sheet steel shear walls with 2:1 aspect ratio and 6-in., 4-in., 3-in., and …

Round-Robin Testing Of A Dewpoint Potentiameter Versus Filter Paper To Determine Total Suction, Thomas M. Petry, Cheng Ping Jiang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Expansive clays exhibit high potential for volume change when changes in soil moisture occur. It has been estimated that the annual cost of damage to facilities built on expansive clay in the United States exceeds $9 billion. the use of soil suction measurements to predict potential clay volume changes has shown significant promise, yet the currently utilized method to determine soil suction, the filter paper method, has serious drawbacks. First, the test takes approximately 8 days to complete, making it less than practical for broad use by practicing engineers. Second, and more troublesome, the filter paper test is difficult to …

Foundations For Seismic Loads, Vijay K. Puri, Shamsher Prakash

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Design of foundations in earthquake prone areas needs special considerations. Shallow foundations may experience a reduction in bearing capacity and increase in settlement and tilt due to seismic loading. the reduction in bearing capacity depends on the nature and type of soil and ground acceleration parameters. in the case of piles, the soil-pile behavior under earthquake loading is generally non-linear. the nonlinearity must be accounted for by defining soil-pile stiffness in terms of strain dependent soil modulus. Several behavioral and design aspects of shallow foundations and pile groups subjected to earthquakes have been critically reviewed. Copyright ASCE 2007.

Assessment Of The Bill Emerson Memorial Cable-Stayed Bridge Based On Seismic Instrumentation Data, Genda Chen, Dongming Yan, Wenjian Wang, Man Zheng, Louis Ge, Frank Liu

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In this study, both ambient and earthquake data measured from the Bill Emerson Memorial Cable-stayed Bridge are reported and analyzed. Based on the seismic instrumentation data, the vibration characteristics of the bridge are investigated and used to validate a three-dimensional Finite Element (3-D FE) model of the bridge structure. The 3-D model is rigorous and comprehensive, representing realistic dynamic behaviors of the bridge. It takes into account the geometric nonlinear properties caused by cable sagging and soil-foundation-structure interaction in the Illinois approach of the bridge. The FE model is successfully verified and validated by using the natural frequencies and mode …

Ccfss Technical Bulletin Fall 2007, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Ccfss News Fall 2007, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

North American Specification For The Design Of Cold-Formed Steel Structural Members, 2007 Edition, American Iron And Steel Institute

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

No abstract provided.

Experiments On Rotational Restraint Of Sheathing, Benjamin W. Schafer

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

No abstract provided.

North American Standard For Cold-Formed Steel Framing -- Header Design, 2007 Edition (Reaffirmed 2012), American Iron And Steel Institute

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

No abstract provided.

Strengthening Of A Reinforced Concrete Bridge With Externally Bonded Steel Reinforced Polymer (Srp), Alexis Lopez, Nestore Galati, Tarek Alkhrdaji, Antonio Nanni

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper introduces steel reinforced polymer (SRP) as a way to strengthen civil structures. This technique consists of cords formed by interwoven high-strength steel wires embedded within a polymeric resin. a comprehensive study addressing analysis, design, installation, load rating and monitoring of a bridge strengthened with this technology is reported. the SRP system was easily installed, demonstrating its similarity to more traditional fiber reinforced polymer (FRP) strengthening techniques. Load tests were performed to evaluate the bridge structural behavior prior and after the strengthening in accordance with AASHTO specifications, showing that the rehabilitation performed as predicted and therefore created the possibility …

On The Formation And Propagation Of Nonlinear Internal Boluses Across A Shelf Break, Subhas K. Venayagamoorthy, Oliver B. Fringer

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

High-resolution two- and three-dimensional numerical simulations are performed of first-mode internal gravity waves interacting with a shelf break in a linearly stratified fluid. The interaction of nonlinear incident waves with the shelf break results in the formation of upslope-surging vortex cores of dense fluid (referred to here as internal boluses) that propagate onto the shelf. This paper primarily focuses on understanding the dynamics of the interaction process with particular emphasis on the formation, structure and propagation of internal boluses on shelf. A possible mechanism is identified for the excitation of vortex cores that are lifted over the shelf break, from …

Additional Shear Wall Values For Light Weight Steel Framing, Reynaud Serrette, Jose Encalada, Georgi Hall, Brandon Matchen, Hoang Nguygen, Alexander Williams

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

This report presents the results of 16 monotonic and 28 cyclic tests of flat strap X-braced walls, steel sheathed shear walls, high aspect ratio shear walls and shear walls framed with 54-mil and 43-mil studs. The findings provided a basis for continued research and development efforts, leading to the establishment of provisions for cold-formed steel-framed diagonal strap braced walls and Type I shear walls.