Engineering Commons^™

Continuity Of Bridges Composed Of Simple-Span Precast Prestressed Concrete Girders Made Continuous, Libin Yin

Dissertations

Bridges composed of simple-span, precast, prestressed concrete girders made continuous via cast-in-place decks and diaphragms are continuous only for live loads and superimposed dead loads. The continuity diaphragms often crack due to time dependent effects in the girders. These cracks not only impair bridge ascetics and durability, but also reduce "degree of continuity". A related issue is that joint construction is time consuming and expensive due to reinforcement congestion. This dissertation presents a series of field tests, analytical studies, and laboratory experiments concerning the design and performance of this type of bridge.

Based on a survey of the state departments …

Determining End & Edge Distance Criteria For Tenon Joints In Timber Structures, Sally Summers Nichols

Masters Theses

Traditionally, timber-frame connections use hardwood pegs to hold the main member within the joint. Currently the end and edge distance criteria for these connections have either been established by tradition or by an equivalent steel bolt diameter approximation. The object of this research is to determine a more specific method to establish the end and edge distances for wood pegs in wood connections. This investigation entails two separate tests that were developed from the standard American Society for Testing and Materials (ASTM) testing methods for steel bolds in wood members.

End and edge distance tests were performed on ¾ inch …

Development Of High Performance Concrete For Use On Tennessee Bridge Decks And Overlays, Charles Herbert Hamblin Jr.

Masters Theses

The purpose of this study was to develop a High Performance Concrete mix design to be used on bridge decks and overlays in Tennessee. A total of eight mix designs were tested in this study. Both gap-graded and dense-graded aggregate combinations were used in the study.

Each mix was tested for fresh and hardened concrete properties. Fresh properties include slump, air content, unit weight, and temperature. Hardened properties include 7 and 28-day compressive strength, freeze-thaw durability, drying shrinkage, and chloride ion permeability.

Although further research is recommended, one promising mix was found as a result of this study. Mix 2F1 …

Genetic Algorithm-Based Model For Determination Of Efficient Management Strategies For Irrigation Canal Networks, Talaat Taher El Gamel

Civil & Environmental Engineering Theses & Dissertations

An optimization model for the determination of efficient management strategies for an irrigation canal network is developed. The objective is to minimize the total water consumed while satisfying various system constraints. An unsteady flow model is used to simulate the flow in the network. A genetic algorithm- (GA-) based framework is used to solve the model. The suitable GA parameters that should be used within the model, as well as the performance of various constraint-handling techniques, are studied. Uncertainties in crop pattern and water consumption rates are incorporated into the search procedure to identify more reliable solutions. A graphical interface …

Pavement Deflection Data As A Tool For The Prediction Of Freeze/Thaw Response, Daner Patrise Truss

Masters Theses

Winter pavement overload permits and spring load restrictions are important to maximize pavement life. In cold regions freeze and thaw conditions have a great effect on the bearing capacity of asphalt concrete (AC) pavement and its sublayers. Studying AC surface deflections from falling weight deflectometer (FWD) tests assists in determining the condition of the surface, base, and subgrade layers of a pavement system. FWD test results are taken from the LTPP Information Management System (IMS). FWD data deflection basin indices can be calculated to analyze AC pavement at different seasonal conditions. This data will aid in determining times when load …

Anevaluation Of Lpile In Comparison To The Measured Behavior Of Prestressed Concrete Piles In Integral Abutments, Jarrell Brandon Tidwell

Masters Theses

The Tennessee Department of Transportation (TDOT) has designed and built integral abutment bridges with prestressed concrete piles for many years. A product of constructing integral bridge abutments is that the piles supporting the structure are exposed to lateral deflections, which come mainly from thermal expansion and contraction of the bridge structure. TDOT funded a project in which the University of Tennessee, Knoxville investigated the effects of the lateral displacement of four 14 inch square prestressed concrete piles that were driven into virgin clay soil.

The tests involved full scale lateral loading each of the four prestressed piles; each pile supported …

An Automated Approach To Analyzing Media Contribution To H-Piles Driven Into Compacted Fills, Alan D. Tackie

Masters Theses

The purpose of this study is to establish the contribution of a soil medium to the behavior of a laterally displaced pile in a displacement-controlled system. Engineers have often assumed that piles driven into well-compacted fills have a lateral response that correlates closely to those driven into undisturbed soils. An investigation into whether this assertion holds throughout the media cross-section forms the crux of this thesis. HPILE, a pile analytic program, was developed by the author of this thesis to foster a quicker analysis of a laterally loaded pile driven into a given media. HPILE uses strain data collected along …

Fatigue Of Drill Pipes Used In Horizontal Directional Drilling, Feibai Ma

Doctoral Dissertations

Fatigue is the most common cause of mini-HDD drill rod failure. It can occur at stress levels far below the normal operating stress in most drill stem components. Fatigue failures occur because the drill rod, after it has been forced into a curved path, undergoes a cyclic bending stress oscillating from tension to compression in concert with the other stress components caused by torque, thrust, or pullback.

When a rod breaks underground, there is considerable extra cost caused by the delay in “fishing” out the broken rod as well as the cost of replacing the rod. On the other hand, …

Parallel Decomposition Procedures For Large-Scale Linear Programming Problems, Yusong Hu

Civil & Environmental Engineering Theses & Dissertations

In practice, many large-scale linear programming problems are too large to be solved effectively due to the computer's speed and/or memory limitation, even though today's computers have many more capabilities than before. Algorithms are exploited to solve such large linear programming problems, either in the sequential or parallel computation environment. This study focuses on two parallel algorithms for solving large-scale linear programming problems efficiently.

The first parallel decomposition algorithm discussed in this study is from the theory problems in a special block-angular structure. The theory or the decomposition principle is first examined. Since the subproblems of a linear programming problem …

Evaluation Of Current Automated Civil Engineer System Non-Appropriated Funds Project Programming Procedures, Joshua C. Ligday

Theses and Dissertations

It is essential that businesses continually improve their automated information systems (AIS) to support the changing needs of the organization. The Air Force civil engineering organization is no exception since they have drastically improved their Automated Civil Engineer System (ACES) through end user support since its implementation in 2000. However, there are many problems associated with the non-appropriated funds (NAF) project programming business rules within ACES. These problem areas were not addressed until recently when an integrated process team met and proposed numerous changes to how NAF programming is accomplished in ACES. This research effort, through a web-based survey, focuses …

Failure Mode Identifications Of Rc Beams Externally Strengthened With, Chris O'Riordan-Adjah

Electronic Theses and Dissertations

The application of carbon reinforced-fiber polymers (CFRP) to structures is a new development that is still under intense research. However, the rehabilitation or retrofit of damage reinforced concrete members by the external bonding of CFRP is becoming increasingly popular in the construction industry. The objective of the tests presented in this thesis is to study different CFRP designs on the reinforced concrete beams and compare their failure modes. The main goal is to determine the CFRP design on the reinforced concrete beams that result in a progressive and gradual failure mode with enough warning before final failure. Different CFRP designs …

Optimal Design Of Pump And Treat Remediation Systems : Treatment Modeling, Source Modeling And Time As A Decision Variable, Karen L. Endres

Dissertations, Master's Theses and Master's Reports - Open

Groundwater optimization and simulation is a maturing science. Research work contained in this thesis extends into areas that have not been fully explored. The incorporation of source and treatment systems selection and design produces information to help decision makers. Further insight is gained by evaluating some of the requirements and standards enforced by regulations such as, remediation time.

The technical aspects of a remediation system are set by the physical properties and the regulatory constraints enforced. As an example, the addition of a realistic treatment system gives more accurate cost estimates, but the pump and treat (PAT) systems parameters do …

Effects Of The Soil Properties On The Maximum Dry Density Obtained Fro, Andres Arvelo

Electronic Theses and Dissertations

In the construction of highways, airports, and other structures, the compaction of soils is needed to improve its strength. In 1933 Proctor developed a laboratory compaction test to determine the maximum dry density of compacted soils, which can be used for specifications of field compaction. The Compaction of soils is influenced by many factors, the most common are the moisture content, the soil type and the applied compaction energy. The objective of this research is the analysis of the maximum dry density values based on the soil classification and characterization. The method of choice in the determination of the maximum …

Detection And Evaluation Of Exisiting Pavement System With Brick Base, Karishma Desai

Electronic Theses and Dissertations

At the turn of the century, the City of Orlando initiated the "Neighborhood Horizon Program." This program involved local citizens to help improve their community resources by engaging in a process of planning where the problems associated with the communities were identified. Many residents favored to bring back the brick roads that were overlaid with asphalt concrete to provided better transportation in the mid 1900s. With majority of the neighborhood streets already bricked, removing asphalt ensured safety, served as a technique for slowing traffic, and added to the historical integrity. Since there were no official documentations available that stated the …

Two Dimensional Linear Finite Element Analysis Of Post-Tensioned Beams, Rodolfo Hutchinson

Electronic Theses and Dissertations

The objective of this research project was to create a Finite Element Routine for the Linear Analysis of Post-Tensioned beams using the program CALFEM® [20] developed at the division of Structural Mechanics in Lund University, Sweden. The program CALFEM and our own made files were written in MATLAB, an easy to learn and user-friendly computer language. The approach used in this thesis for analyzing the composite beam consists in embedding the steel tendons at the exact location where they intersect the concrete parent elements, without moving the concrete parent element nodes. The steel tendons are represented as one dimensional bar …

Modeling Crash Frequencies At Signalized Intersections In Central Flor, Smitha Kowdla

Electronic Theses and Dissertations

A high percentage of highway crashes in the United States occur at intersections. These crashes result in property damage, lost productivity, injury, and even death. Identifying intersections associated with high crash rate is very important to minimize future crashes. The purpose of this study is to develop efficient means to evaluate intersections, which may require safety improvements. The area covered by the analysis in this thesis includes Orange and Seminole Counties and the City of Orlando. The aforementioned counties and city thus represent Central Florida. Each County/City provided data that consisted of signalized intersection drawings that were either in the …

Slope Stability Analysis Of Class I Landfills With Co Disposal Of Bios, Mrutyunjay Vajirkar

Electronic Theses and Dissertations

Land filling provides a major, safe, and economical disposal route for biosolids and sludges. With an expanding world, the demand for larger and higher capacity landfills is rapidly increasing. Proper analysis and design on such fills have pushed the boundaries of geotechnical engineering practice, in terms of proper identification and assessment of strength and deformation characteristics of waste materials. The engineering properties of Municipal Solid Waste (MSW) with co-disposal of biosolids and sludges with regards to moisture characteristics and geotechnical stability are of utmost importance. Significant changes in the composition and characteristics of landfill may take place with the addition …