Theses and Dissertations - Department of Civil, Construction & Environmental Engineering
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Item A Historical Development and Prediction of the Future Water Quality in the Black Warrior River in the Vicinity of Tuscaloosa, Alabama(University of Alabama Libraries, 1967) McClure, Nathaniel DeHass IV; University of Alabama TuscaloosaIt is generally recognized that the Black Warrior River is a classic example of unrestricted use of a stream as a receiving body for the disposal of sewage and industrial wastes. A section of this river, in the vicinity of Tuscaloosa, Alabama, has been selected for this presentation. The area studied begins upstream at Holt Lock and Dam, river mile 347.5, and has a downstream limit of river mile 309.5 which is four miles below the mouth of Cypress Creek. These limits were selected because they cover all significant pollutional effluents received by the Black Warrior River in the Tuscaloosa area. Another unique factor concerning these limits is that the relative quality of the water both upstream and downstream of these limits is good while portions of the area to be considered are grossly polluted--especially during periods of low flow.Item Using design-based change orders as a lessons learned metric in university dormitory construction(University of Alabama Libraries, 2009) Stone, Matthew Lee Cole; Johnson, Philip W.; University of Alabama TuscaloosaThe enrollment at The University of Alabama has increased substantially in recent years and the University is expanding to meet the growing demands. The expansion includes four dormitory complexes built within the past five years. Change orders considerably influenced the final cost of the first and second dormitory projects and the University initiated the current study to follow-up on a global change order study that previously examined new construction on campus. The current study is part of a lessons learned initiative to improve the cost effectiveness of University construction projects. New dormitory construction projects were the main focus of this study and the change data from these facilities was analyzed based on the reasons for the change and what Construction Specifications Institute (CSI) Division the change represented. While it was determined that the largest source of change orders on dormitory projects were owner initiated, these changes have not been targeted for reduction since they are at the discretion of the University and can be beneficial to the project. To gauge the performance of the change management program currently in place at the University, the direct impact on the total project cost due to changes resulting from design errors were analyzed for all four dormitory projects. The author hopes that the recommendations in this study will aid universities and colleges by providing a means to gather, track, and analyze changes that occur during the construction of dormitory projects and show how the lessons learned from the change orders during these projects can potentially reduce costs on future projects.Item Selection of a simulation software to model a small signalized system of a multilane arterial in the southeastern US(University of Alabama Libraries, 2009) Tedla, Elsa Gebru; Turner, Daniel S.; University of Alabama TuscaloosaEmployment of traffic simulation tools has become a popular practice in traffic operations analyses as the transportation system has become more complex and more frequently congested. Most of the commercially available traffic simulation models work best for free-flow or unsaturated conditions. Depending on the type of traffic condition and type of analysis, the performance of simulation models varies and there is little information available to help the analyst to select the most appropriate and accurate model for a given analysis. To address this need, two traffic simulation tools, SimTraffic and AIMSUN, were evaluated and compared for a congested arterial segment. Both simulation packages are designed to model almost any combination of surface street and freeway facilities. In this paper, an arterial segment in Tuscaloosa, Alabama (McFarland Boulevard) between 13th street and 31st street was coded and simulated for AM, Mid day, and PM peak periods. The network was simulated 10 times for each peak period using both simulation models, and average values were taken for comparison. Then the network was evaluated using output measures of effectiveness (MOE) such as Vehicle Hours Travel (VHT), Vehicle Miles Travel (VMT), average speed, and flow rate at the network level, along with delay, travel time, and average speed at the arterial level, and delay and traffic volume at a link level. Using statistical methods and graphical plots for comparison, each simulation model was evaluated for its capability to replicate existing field conditions using default and calibrated traffic parameters. In addition to accuracy, the models were also compared with respect to ease of coding, and quality/usefulness of output. This report documents relevant results and calibration processes used for employing the models in future studies and practices regarding congested arterials.Item The Supervising Discipline Engineer's (SDE) role in the Front End Planning Process(University of Alabama Libraries, 2009) Ingram, Clayton Bryant; Back, W. Edward; University of Alabama TuscaloosaThe Supervising Discipline Engineer's (SDE) role in the Front End Planning (FEP) Process is thought to be an important one by engineering managers at an Engineering, Procurement and Construction (EPC) firm. Although FEP and the role of the SDE have been defined independently, the roles of the SDE in the FEP process lack proper definition and understanding to achieve the much needed alignment of the two. It has been assumed that the SDE has higher levels of involvement in technical roles, based on their job description, but it was important to reinforce this through the research. The information contributed to the FEP process by the SDE is needed in a timely manner and crucial to project success. Therefore, it is important to define these roles and the level of involvement the SDE takes part. The research addresses this issue. It identifies the roles in which the SDE participates in the three phases of Front End Planning as defined by the Construction Industry Institute. The CII model was chosen based on industry "best practice" as adopted by URS Washington Division, the EPC firm evaluated in this research. Six core engineering disciplines were evaluated, as determined by URS Washington Division, and are as follows: (1) Architectural, Civil, Environmental, and Structural (ACES); (2) Electrical; (3) Instrumentation and Controls (I&C); (4) Mechanical; (5) Piping; and (6) Process. A group of SDEs, from a variety of disciplines, participated in a skills development program defining the activities involved in FEP. Once concluded, the SDE was to rate their level of involvement on a survey questionnaire developed by the research team for each activity. Based on the results, the research found conclusive evidence to define the level of involvement of the SDE in the FEP process. Furthermore, conclusions drawn from these respondents reinforced the high levels of involvement in those technically driven activities and elaborated on the role of the SDE in relation to the less technical activities. Last, from the analysis of the data collected, a matrix was developed outlining the roles of the SDE in general, and the roles of the SDE according to discipline.Item Use of microscopic traffic simulation and field data to investigate saturated and free flow traffic conditions at arterial signals(University of Alabama Libraries, 2009) Gurupackiam, Saravanan; Turner, Daniel S.; University of Alabama TuscaloosaOver the years microscopic traffic simulation has evolved as the premier tool to analyze complex and congested transportation networks. However, despite the robustness and wide spread use of traffic microsimulation, some gaps and limitations still exist that can affect the accuracy of these models' results. Moreover the change of traffic characteristics and driver behavior during the transition from undersaturated to saturated condition is not completely understood. This dissertation addresses these two issues. The road network chosen for the microscopic simulation and field data collection is a six lane main traffic artery located in Tuscaloosa, Alabama, USA. The entire research work contains three related research efforts, each conducted along the topic of this dissertation. The first research thrust focused on the sensitivity and accuracy of the microscopic traffic simulation. Specifically it investigated the sensitivity of MOEs to simulation initialization time, required number of repetitions, and major contributors of variation in MOEs. The second research thrust dealt with field investigation of operational parameters including gap acceptance and lane changing during different levels of traffic flow. The final research effort explored the variations in simulation results using existing embedded/default values of lane change parameters (lane change duration and look ahead distance), versus using values obtained from field observation for both free flow and saturated traffic conditions. From all the research efforts, the following broad conclusions were drawn, * Traffic flows at signals that are approaching saturation are still complex to analyze, and the interactions between traffic parameter are not well understood. * When traffic flow on a typical arterial approaches saturation, drivers take higher risks (eg: drivers accept smaller gaps). * A statistical analysis of gap acceptance and lane changing confirmed what is suspected intuitively. * Existing traffic microsimulation tools simplify some of the traffic parameters in simulation models. These parameters may be recoded or recalibrated for better accuracy of simulation results. * In traffic microsimulation an increased number of simulation runs certainly helps in stabilizing the variability of the MOE and it is advisable to use a longer simulation time (eg. 60 minutes) to reduce the variation of MOEs.Item Effectiveness measurement of a training program developed for supervising discipline engineers(University of Alabama Libraries, 2009) Morriss, Robert Chadwick; Back, W. Edward; University of Alabama TuscaloosaThis research investigates a methodology to effectively assess the development of supervising discipline engineers' management skills resulting from a structured, in-class, development program. Civil, mechanical, electrical, structural, industrial, instrumentation and controls, and process disciplines must work together when designing large engineered projects. In order to stay competitive, engineering firms must find a way to rapidly, but effectively, train their engineers to become qualified leaders in their discipline. They must accelerate the learning of management skills that are necessary in today's industry. A structured, efficient method of training must be developed to provide design professionals with the necessary information without sacrificing day-to-day productivity. In order to determine if the skills development was successful, however, it is necessary to measure the effectiveness of the program. The first aspect of this research focused on developing a delivery method for a supervising discipline engineer skills development program. An efficient means by which to measure the effectiveness of the program was then addressed. Finally, the resulting data gathered from the program evaluation was analyzed in order to determine whether or not the program was successful in meeting the course objectives. The results of the data analysis revealed that the skills development program had significantly improved the engineering management skills of the participating supervising discipline engineers.Item Conditional cell transmission model for two-way arterials in oversaturated conditions(University of Alabama Libraries, 2010) Wang, Ping; Jones, Steven L.; University of Alabama TuscaloosaIn 2007, congestion caused urban Americans to travel 4.2 billion hours more and to purchase an extra 2.8 billion gallons of fuel for a congestion cost of $87.2 billion - an increase of more than 50% over the previous decade. Urban arterials operating in oversaturated conditions are now very common and are expected to become even more prevalent. As a result, there is an urgent need to explicitly address oversaturation. Simulation of oversaturation plays an important role in addressing it. However, the previous research, including existing traffic simulation software and theoretical approaches, take full account of traffic flow on two way arterials in oversaturated conditions. Therefore, improvements of existing traffic flow model simulation techniques are necessary to adequate study such fully oversaturated arterials. The objective of this research is to develop a novel feature for traffic flow models, to simulate when traffic queues on two way arterials periodically extend until then block an upstream signal in oversaturated conditions. Such a model should be capable of delineating the dynamic of traffic flow created by the merging and diverging activities on two way arterials. In additional, it should have the capability of describing blockages, spillback and shock wave phenomena along the oversaturated arterials. The Cell Transmission model (CTM) is used in the dissertation, because it can accommodate all traffic conditions from light condition to oversaturated condition. However, it has limitations and has only recently been extended from one way two way arterials. Two way arterials have more diverge and merge activities at intersections, which make the coding of CTM more complex and time-consuming. Second, a noticeable inaccuracy in prior CTM research is the failure to simulate the blockages at intersections. They typically estimate the delay occurring on segments and ignore the delay occurring at intersections. These limitations affect CTM's accuracy and limit its use. To enhance CTM, a conditional cell transmission model (CCTM) is developed with two improvements. First, CTM is expanded for two-way arterials by taking account of all diverge and merge activities at intersections. Second, a conditional cell is added to simulate periodic spillback and blockages at an intersection. The cell exists conditionally, depending on whether or not there is a spillback at an intersection. In other words, if spillback happens, the conditional cell exists and stores the vehicles which spill back into the intersection; if there is no spillback, the conditional cell will not exist. In CCTM, users may input the probability of a conditional cell (drivers breaking the driving rule) and probability of occurrence of useful location of a gap to match the characteristics of local drivers' behavior. This is a unique contribution of CCTM. The CCTM traffic flow simulation was initially developed using evolutions of small model of six cell mode. It included (a segment cell, a diverge cell, a cell in front of an intersection, a cell in a left turn lane, a cell in the minor street and a conditional cell). They were loaded with light duty traffic, moderate duty traffic and heavy duty traffic respectively. To test the overall performance of CCTM, a series of experiments are designed and performed for a multilane, two-way, three-signal sample network. Experiments were conducted to give sensitivity analyses to four user-defined parameters including traffic demand, traffic signal timing, possibility of occurrence of a useful gap and possibility of a conditional cell. The results demonstrate that CCTM can accommodate various traffic demands and CCTM's accurate representation of traffic flow. Finally, to validate CCTM, it is compared with HCS (Highway Capacity Software 2000). Three scenarios of traffic demand are inputted into HCS and the results of travel speeds are compared with those of CCTM. The consistency between HCS 2000 and CCTM shows that CCTM is a reliable methodology of modeling traffic flow in oversaturated condition.Item Analysis and rehabilitation of the 1882 wrought iron bridge(University of Alabama Libraries, 2010) Mathis, Brandi Price; Richardson, James A.; University of Alabama TuscaloosaThe Friends of Historic Northport in conjunction with the City of Northport planned to relocate and preserve an existing span of a bridge that originally crossed the Black Warrior River in 1882. The 1882 Bridge is an old wrought iron arch-shaped truss bridge manufactured by the King Iron and Bridge Company of Ohio. A tensile test and metallographic analysis were performed on samples taken from the bridge, and it was determined that the bridge is composed of at least two grades of wrought iron. The tests also indicated the presence of brittle iron. The wood decking system, the concrete bridge abutments, and the keystone retaining wall for the bridge approaches were designed for material quantities for the relocation project. A structural analysis of the bridge at its new location showed that some of the bridge members were slightly overstressed under certain loading conditions. Parts of the top chord, floor beam, and diagonals were overstressed under the dead and pedestrian loads, and the bottom diagonals were overstressed under the wind load. Four lifting methods were analyzed for the bridge's relocation. The method considered the most efficient was to attach the lifting cables directly to the top chord near the ends of the bridge.Item Development of the pilot car driver certification program for Alabama(University of Alabama Libraries, 2010) Wilkes, Mary Elizabeth; Lindly, Jay K.; University of Alabama TuscaloosaOversize and overweight loads are an essential part of the economy and current life. Unfortunately, with these loads comes a potential danger to the public. Roads, bridges, and railroad crossings are not built to support these loads or allow for easy access. Pilot car escorts are an essential element to safely and efficiently moving the oversize loads. These escorts have the responsibility of keeping the public and load safe. Yet, only eleven states have training and certification requirements for the driver of the escort vehicle. Alabama is not one of these eleven states. The Alabama Department of Transportation (ALDOT) partnered with the University Transportation Center of Alabama (UTCA) to develop a program. This thesis documents the development of the Alabama Escort Driver Certification Program and focuses on the development of the curriculum. For the escort driver certification program to be effective, The Code of Alabama must be updated to include certification requirements. After extensive research, UTCA staff recommended changes to The Code of Alabama to update the rules and regulations regarding pilot/escort driving. UTCA also suggested course logistics such as course instructors, course availability and locations, class size, budget, proof of certification, and course evaluation. UTCA then developed a one day (eight hour) curriculum based on Florida's current curriculum. Participants must attend the course, demonstrate proper flagging technique, and pass a written exam with a minimum score of 80% to receive certification. The thesis also describes the multi-media presentation, instructor's manual, and participant's manual's content format and content. The development of a website to serve as a media for advertisement and a registration aid is also presented. This report documents relevant information and decisions made in the development of an important and possibly life-saving program.Item Characteristics of urban development and associated stormwater quality(University of Alabama Libraries, 2010) Bochis, Elena-Celina; Pitt, Robert; University of Alabama TuscaloosaUrban land uses and their associated impervious cover increase the quantity and worsen the quality of stormwater runoff, which can seriously impair receiving waters. It is known that there is considerable variability in runoff quantity and quality between rain-to-rain events due to rainfall spatial variability. In addition, runoff presents significant variability between neighborhoods, even if they are affected by the same rain event. It is hypothesized that the variability in stormwater quality between sites is associated with the difference in land uses and surface covers. This research examined the variability in stormwater quality characteristics as contained in the National Stormwater Quality Database (NSQD) for different land use categories and nine selected stormwater constituents (TSS, total zinc, total copper, total lead, total phosphorous, dissolved phosphorous, total nitrogen, TKN, and fecal coliform) at different geographical scales - national, regional (EPA Rain Zone 2), and local levels (Jefferson County, AL). The results of the local data analyses were compared to the results obtained from the national and regional analyses. This research also examined the detailed land development characteristics based on actual local field measurements and explained how this variability affects the variability in stormwater characteristics. The land development characteristics information was collected from Little Shades Creek watershed and five highly urbanized drainage areas situated in Jefferson County, AL (in and near the city of Birmingham). About 170 neighborhoods were surveyed in detailed to determine the actual development characteristics and their variability. This research found that each major land use had unique patterns and mixtures of surfaces. These, in addition to the activities taking place within the land uses, affect the runoff quality and its variability from these areas. It was found that there is less variability in stormwater quality characteristics within each land use category compared to the variability between the land use categories. This finding is also true for land cover areas in that there are lower levels of variations in these area types within each land use compared to between the different land uses. The results from this dissertation analyses can be used as guidance for local stormwater quality monitoring efforts, but the specific results are not all expected to be applicable everywhere. The main focus of this research was in investigating stormwater variability, specifically its sources and how it can be reduced. The general concern with the high variability that is associated with stormwater quality is the uncertainty of being able to meet discharge requirements, even with extensive use of stormwater control practices. This uncertainty can be eliminated, or at least reduced, by a better understanding of sources of this variability. Specifically, appropriate discharge regulations that recognize this variability will assist the stormwater managers to better use their financial resources and to maximize receiving water quality improvements.Item Queue predictions at temporary work zones: modification and testing of an existing spreadsheet(University of Alabama Libraries, 2010) Wang, Mengxiao; Batson, Robert G.; University of Alabama TuscaloosaAt the Alabama Department of Transportation (ALDOT), the tool used by traffic engineers to predict whether a queue will form at a freeway work zone is the Excel-based "Lane Rental Model" developed at the Oklahoma Department of Transportation (OkDOT) and whose work zone flow capacity values are based on the 1994 Highway Capacity Manual (HCM, 1994). The scope of this research pertains only to the queue estimation worksheet of that spreadsheet tool, herein referred to as the OkDOT baseline version. This tool, based on input-output logic, is simple to understand and use. Preliminary testing of the OkDOT baseline spreadsheet confirmed a lack of accuracy, and an opportunity to update the capacity estimation method while keeping the rest of the tool intact. Two other versions were created using the work zone lane capacity model of HCM 2000: the HCM 2000 version uses work zone intensity effects of -160 to +160 passenger cars per hour per lane (pcphpl), as prescribed in HCM 2000; the second modified version uses work zone intensity penalties of -500 to 0 pcphpl, a modification based on recent literature, and is, therefore, called the HCM 2000 hybrid version. Although work zone capacity estimation has been widely researched over the past three decades, only a few studies measured actual queue start times, queue lengths (hence maximum queue length); almost all utilize the free flow traffic volume approaching the work zone and predict the capacity of the work zone (rate of traffic exiting the downstream end of the work zone). One in particular (Sarasua et al. 2006) collected extensive data on lane capacity and queue characteristics (if a queue formed) at 35 freeway work zones in South Carolina. We use 32 of these work zone descriptions as the "test data bank" for comparing predictions produced by three versions of the OkDOT spreadsheet tool with the actual maximum queue length (MQL) and queue start time (QST). Minimizing the prediction error in MQL is the main criterion for comparing the accuracy of the three OkDOT model versions, though QST was also considered. Based on the analysis and evaluation, the strong conclusion is that the current tool should be replaced by the HCM 2000 hybrid version we have developed and tested. The HCM hybrid version minimized error in predicting actual MQL at the 32 SC work zones, and minimized the error of not predicting a queue, when one actually formed. Additional testing revealed that a passenger car equivalent PCE = 2.1 for heavy vehicles minimized error in MQL among typical PCE values in the range [2.0, 2.5]. This tool was validated using six work zone cases, three from Alabama and three from North Carolina. In addition to modification of the capacity estimation method in the OkDOT tool, we endeavored to make it more useful for mobility impact assessment by including a graphical depiction of the queue profile. A CD with the HCM 2000 hybrid version of the software was delivered to ALDOT with a final report. A detailed user's guide was prepared and is included as an appendix to this thesis.Item Leadership development in the construction engineering industry(University of Alabama Libraries, 2010) Struyf, Sammy; Back, W. Edward; University of Alabama TuscaloosaThis research investigates a methodology to effectively assess the development of leadership training in the construction industry. The construction industry is one of the largest industries in the world and in order to stay competitive, engineering firms must find a way to train their employees to become qualified leaders in their specific discipline. A structured, efficient method of training leadership skills must be developed to provide construction and design professionals with the necessary information to become successful without sacrificing day-to-day productivity. Two leadership training methods were developed for this thesis research. In order to determine if these leadership training programs were successful, it was necessary to measure the effectiveness of these programs. The first aspect of this research focused on developing a delivery method for a leadership training development program. An efficient means by which to measure the effectiveness of the program was then addressed. Finally, the resulting data gathered from the program evaluations was analyzed in order to determine whether or not the program was successful in meeting its objectives. The result of the data analysis revealed that the leadership development program had significantly improved the leadership skills of the participating construction and design engineering professionals.Item Transit evacuation planning for Mobile County, Alabama(University of Alabama Libraries, 2010) Kumlachew, Menasse Teklewold; Turner, Daniel S.; University of Alabama TuscaloosaThe main objectives of this thesis research were to: (1) estimate the potential number of transit dependent individuals during a major hurricane event and (2) provide information describing how to effectively communicate with these individuals before, during and after an emergency evacuation. Mobile County was used as a case study. Mobile County is one of the two Alabama coastal counties exposed to the effects of hurricane storm surges, wind and rain. The amount of danger the residents face depends on the intensity of hurricanes, the locations of the individuals, and the amount of prior preparation and planning by emergency agencies. During these events special needs individuals are the primary endangered people since they require special assistance to evacuate and are not usually included in emergency evacuation plans. Since special needs populations are diversified, and mostly isolated, it is difficult to identify, locate and communicate emergency information with them. The study reviewed several reports and guidebooks published by federal and state emergency management agencies. This review was supplemented by contacting individuals working in the area of emergency management and evacuation of special needs populations. The study identified a variety of communication systems which can be applied in emergency information communication. The systems' limitations and strengths in serving the special needs individuals were assessed based on the literature. The number of potential transit dependent populations was estimated in three ways. Each method used a different dataset: (1) Census 2000, (2) 2006 American Community Survey and (3) Harvard Telephone Survey. There were several major findings for this part of the study: 1. There was a general correspondence between the three estimates, but it was not strong enough to make a statistical comparison. 2. The census data and American Community Survey data contain large standard errors, as much as ±30% at a 90th percentile confidence level. 3. The actual numbers of evacuees for previous categories 3 and 2 hurricane events near Mobile County were less than 11% of the average predicted levels. In summary, this study provided information to assist Mobile County prepare evacuation plans to deal with extreme events.Item The student pipeline to the oil and gas industry(University of Alabama Libraries, 2010) Peck, Benjamin Allen; Back, W. Edward; University of Alabama TuscaloosaThis research investigates recruitment strategies, techniques, and trends that can benefit the oil and gas industry in hiring engineering graduates. Engineering occupations are rising in demand within the oil and gas market. This is due to a workforce nearing retirement age and the industry's ongoing efforts to establish new technologies that maximize the earth's energy resources. With the creation of new positions, employers like URS-Washington Division are competing for employees from a diminished workforce pool. This research helped to establish proactive strategies that companies use to interest students in the industry. The approach to exploring oil and gas recruiting was carried out in two phases, industry and academic. The first of these phases sought input from industry professionals, which helped in formatting a questionnaire and survey. The second phase involved development of a second questionnaire that targeted students, faculty, engineering career service directors, and URS-WD employees hired within the last two years. All the information gathered from the surveys and telephone interviews were analyzed to establish recommendations which can be made to the industry. What was found is that employers are targeting a new generation of engineers that have differing priorities and needs than the generations preceding them.Item Environment-assisted subcritical crack growth in CFRP externally bonded concrete systems(University of Alabama Libraries, 2011) Jennings, Elaina Noel; Wang, Jialai; University of Alabama TuscaloosaThe nation's current state of infrastructure is at an increasing rate of disrepair with new methods of cost-effective rehabilitation being considered over timely and costly reconstruction. Externally bonding carbon fiber-reinforced polymer plates to the tension side of a flexural beam has been one such method that has proven effective and reliable due to the outstanding performance and various advantages in CFRP materials. Gaps in long-term durability studies have been the major reason why this strengthening technique has not seen more success. It is fundamental and crucial that the mechanism of the bond interface between concrete and the strengthening material be thoroughly tested and understood. It is the intention of this study to further increase the knowledge and understanding of the long-term durability of the concrete/adhesive interface while being exposed to various aggressive environments in such externally bonded systems. Firstly, a systematical and comprehensive literature review regarding the use of CFRPs as external reinforcement, the effects of various aggressive environments on the materials being tested, and the application of linear elastic fracture mechanics is presented. An experimental study is conducted using the Boeing wedge test with a digital image correlation technique used to analyze the subcritical crack growth along the concrete/adhesive interface. Results show that subcritical cracking does exist along this interface and its effects can be significant. A theoretical study is conducted to predict the long term debonding behavior by deriving an analytical model based on Euler-Bernoulli beam theory and linear elastic fracture mechanics representing the Boeing wedge test specimen as a double-cantilever beam extending off of a Winkler elastic foundation. A finite element analysis of the test set-up is conducted as verification of the analytical model. Results of this study can and should be included in the long-term durability section to be used as an indicator of maintenance in all future infrastructure rehabilitation plans made at the federal, regional, and state levels.Item Development and testing of protocols for evaluating emerging technologies for the treatment of stormwater(University of Alabama Libraries, 2011) Togawa, Noboru; Pitt, Robert; University of Alabama TuscaloosaThe primary objective of this research is to examine different testing protocols used to evaluate the removal capabilities of small stormwater control devices. The focus of the field research is to examine the different methods that have been used to measure the performance of stormwater control devices. Detailed field evaluations of the Up-Flo® Filter, which was, in part, developed by engineers at the University of Alabama through a Small Business Innovative Research (SBIR) grant from the U.S. Environmental Protection Agency, are used to evaluate and compare the different evaluation protocols. Past data from laboratory and pilot-scale tests that examined unit process performance are also used in the examination of the different evaluation protocols. Therefore, different evaluation tests were conducted under many different scales and conditions to determine the expected performance of the Up-Flo® Filter. This is a unique opportunity to examine the results of these different tests to compare and determine which results are also reflected during the full-scale observations under actual rain conditions, and to determine the performance insights which were found during the different testing methods. The evaluation testing is based on the available protocols, including: TAPE, TARP, NJCAT, and ETV, extended to incorporate additional information. The aim of this research is to recommend modifications to these protocols and to develop a more robust testing and evaluation procedure that can be better used under a broad range of conditions, considering scaling issues and uncertainties associated with different testing environments. Even though these tests examined a single technology in detail, it is expected that the insights obtained pertaining to evaluation protocols would apply to other similar devices (relatively small flow-through systems having limited storage capacity for the treatment of stormwater).Item Mechanics and subcritical cracking of FRP-concrete interface(University of Alabama Libraries, 2011) Zhang, Chao; Wang, Jialai; University of Alabama TuscaloosaThe need for safe, effective, and efficient methods to strengthen and upgrade our nation's infrastructures is clear. Strengthening Reinforced Concrete (RC) members using Fiber Reinforced Polymer (FRP) composites through external bonding has emerged as a viable technique to retrofit/repair deteriorated infrastructures. The interface between the FRP and concrete plays a critical role in this technique. This study proposes a life-cycle analytical framework on the integrity and long-term durability of the FRP-concrete interface through a combined analytical, numerical, and experimental approach. A novel three-parameter elastic foundation model (3PEF) is first established to provide a general tool to analyze and evaluate the design of the FRP strengthening system. This model correctly predicts the location where debonding can occur. To simulate the interface stress redistribution and creep deformations accumulated during service life due to the strong time dependent features of the adhesive layer, linear viscoelastic analytical solutions are then developed for the FRP-strengthened RC beams. Small cracks usually exist within the FRP-concrete interface, making fracture mechanics a more appropriate tool to evaluate the integrity of the FRP-concrete interface. Analytical solutions of energy release rate (ERR) and its phase angle at the tip of a crack along the FRP-concrete interface are obtained. Under the synergistic effects of the service loads and environments species, these small cracks can grow slowly even if the ERR at the crack tip is lower than the critical value. This slow-crack growth process is known as environment-assisted subcritical cracking. A series of subcritical cracking testing are conducted using a wedge-driven testing to gain the ability to accurately predict the long-term durability of the FRP-concrete interface. It has been found that water, deicing salt and alkaline solutions can substantially reduce the ERR at the crack tip needed to drive the subcritical crack growth along the epoxy-concrete interface. Once the small cracks grow to the critical length, critical debonding will occur, leading to the premature failure of the structure. A nonlinear fracture mechanics model using a Cohesive Zone Model (CZM) is finally developed to simulate this final failure phase of the FRP-concrete interface.Item An exploratory case study of offshore outsourcing within downstream structural steel engineering services(University of Alabama Libraries, 2011) Salunke, Rakesh; Grau, David; University of Alabama TuscaloosaAlthough the offshore outsourcing trend continues to grow in the Architectural Engineering and Construction industry, research on the downstream design services has been fairly limited. In this thesis, we investigate downstream structural steel engineering services offshored from the United States to India. Employing ethnographic data collection method, we conduct face-to-face semi-structured interviews and telephonic interviews of US client and Indian vendors. Supporting evidences are gathered from multiple sources of data such as process checklists, minutes of meetings, and sample documents. Data analysis reveals 6 key constructs and 16 sub-constructs that address the issues and areas of concerns associated with offshore outsourcing of downstream design services. The key constructs include unrealistic contractual obligations, lack of constructability focus, inefficient design information exchange, technology interoperability issues, virtual team misalignment and internal team misalignment. We further assess our constructs' validity by testing for matching patterns between observed constructs and organizational theories--Institutional theory, Transaction Cost Economics (TCE) theory and Resource Based (RB) theory. Based upon the observed matching patterns we show that these theories can be used to understand the issues and problems arising due to off shoring of downstream design services. Through this theoretical categorization we generalize our findings across a wide spectrum of downstream engineering disciplines in the AEC industry. This research characterizes the offshore outsourced downstream structural steel engineering services and provides understanding of the critical problems and issues prevailing under the attractive surface benefits within offshore outsourced downstream design services.Item Bridge weigh-in-motion deployment opportunities in Alabama(University of Alabama Libraries, 2011) Brown, Alan James; Jones, Steven L.; Richardson, James A.; University of Alabama TuscaloosaOverweight vehicle enforcement is a continuous problem for all state Departments of Transportation. Various technologies are in use across the US to aid in the enforcement of vehicle weight limits. However, to date, no technology has been shown to be a definitive solution. The various technologies currently available were researched and the pros and cons of each highlighted. Focus was placed on Bridge Weigh-in-Motion (B-WIM) and an extensive literature review has been conducted following all developments in the field of B-WIM since 1979. The advantages of B-WIM include its ease of installation, portability and potential for high accuracy vehicle weight measurements. Accuracy however is site specific, which makes the selection of a bridge an extremely important element in the success of a B-WIM installation. A bridge selection tool prototype was developed using ArcGIS. The tool was designed to select bridges with the physical characteristics associated with achieving high B-WIM weight measurement accuracies. Daily truck volumes and current Weigh-in-Motion (WIM) sites were also included in the tool to allow for an effective choice of route for installation. As the systems use cellular data signals to transfer data to the weigh crew during the pre-selection process, cell service maps were also included in the tool. The prototype showed that such a tool is feasible and should be beneficial for ALDOT. ALDOT owns two B-WIM systems which it intends to use for overweight vehicle enforcement. An accuracy test of the system was conducted. A bridge in West Alabama was selected for installation. Calibration was conducted and random vehicles were statically weighed to verify the accuracy of the system. A gross vehicle weight accuracy of B (10) was obtained which is more than sufficient for pre-selection of potentially overweight vehicles. Alternative sensor locations and orientations were also investigated and signals were compared. It was found that longitudinal axle detectors located close to the bridge supports provided the cleanest and most distinct signals at the test location. Weighing sensors located at the mid-span provided the best signals for weighing trucks.Item Development of a low cost, rapid detection method for Escherichia coli(University of Alabama Libraries, 2011) Grammer, Phillip John; Brown, Joe M.; University of Alabama TuscaloosaReducing the burden of water-related illness requires better monitoring for fecal contamination so that risks can be identified and controlled. Currently used tests do not provide rapid feedback on drinking water risks, are often bulky and expensive, and are not well suited for field use. We developed a novel test method based on a specific antigen/antibody reaction to create a visual indication of the presence of E. coli; in a water sample. We used a latex agglutination technique employing E. coli; specific antibody coated microparticles (MPs) as an identification method, preceded by a recovery step and growth period to enhance concentrations to detectable levels. E. coli; in laboratory prepared waters were recovered via membrane filtration, grown to titers sufficient for MP use, and interacted with MPs to provide a quantal (presence/absence). The growth rate of E. coli; in liquid media after concentration by membrane filtration was investigated, as well as the role of elution of E. coli; from the membrane filter. The detection limit of antibody coated microparticles was also determined. Results showed low correlation (-0.150) between average recovery rate and average 0 - 6 hour doubling time, indicating low need for bacterial elution. The subsequent growth step yielded an average replication of 660,000 the original membrane filter count at 9 hours, with an average doubling time in log phase growth of 21.5 minutes. Results suggest a lower detection limit of approximately 13,000,000 cfu/mL for E. coli; using antibody coated microparticles. Coupled together, the test can positively detect a single E. coli; cfu in the original sample after incubation for 11 hours (95% CI). Required minimum incubation times for detection of 10 cfu and 100 cfu were 9 hours 50 minutes, and 8 hours 40 minutes (95% CI), respectively. The novel method provides a promising method of decreasing both the cost of field water testing and time required to provide results. Doing so would greatly improve the ability to identify and reduce the effect of fecal contamination in drinking water sources.