Master of Science / Department of Civil Engineering / Sunanda Dissanayake / Speed management has been a challenge, particularly in places where high-speed highways pass through. Due to high rate of fatalities and low budgets available, it is therefore necessary to identify low-cost effective approaches in reducing speeds. Optical Speed Bar (OSB) treatment is one such technique. This research makes an attempt to evaluate the effectiveness of OSBs in reducing approach speeds on two-lane, rural highways approaching small communities. Speed data were collected and analyzed “before” and “after” periods at five sites. Effectiveness of OSBs was evaluated using changes in mean and 85th percentile speeds under different categories by considering all vehicles, vehicle classification (two axles vs. more than two axles), day of the week (weekdays vs. weekends), and time of day (daytime vs. nighttime), as well as proportions exceeding posted speed limit, using t-test mean speeds, F-test for analysis of variance, and Z-test for proportions of vehicles exceeding posted speed limit between “before” and “after” datasets. Even though motorists were found to slow down on the approaches, in response to speed zones, speeding was noted. “Before” speed data indicated higher speeds than desired at the sites. The 85th percentile speeds were between 50 and 63 mph while the posted speed limits on the approaches were 45 mph at four sites, and the 85th percentile speed was about 42 mph at one site with an approach posted speed limit of 30 mph. The “before” degrees of noncompliance were up to 90 % of free-flowing vehicles at the sites. Speed data analysis showed significant reductions in speeds at ends of OSBs at four test sites. Mean and 85th percentile speeds and standard deviations were found reduced in the after periods. Percent reductions in mean speeds were between 1.2 and 8.2 %, with 85th percentile reductions between 3.2 and 8.9 %. At one site, no notable change in mean and 85th percentile speeds occurred at the end of OSBs, but significant increases in standard deviations were noted. Speed reductions were higher for two-axle vehicles, during the daytime and on weekdays with few exceptions. Results of the study showed, as other previous studies did, OSBs may have some minor effects on vehicle speeds. The study provides an indication that it may be possible to create safety improvements as result of using OSBs on the approach to a rural community. However, magnitude of speed reductions was generally small, though the reductions were statistically significant at the 95% confidence level. Because of the non-consistence of the magnitude of speed reductions at the test sites, no conclusion can be drawn as to how much OSB treatment reduced speeds. These results were based on “after” periods up to five months. Therefore, further study would be required to determine whether these safety improvements are sustained over an even longer time period. Even though minor speed reductions occurred, speeds observed at the sites were still higher than the posted speed limits, indicating OSBs were not effective enough in providing the desired speed limit compliance. Additional studies would be helpful to identify combinations of countermeasures, for instance OSBs and other techniques, effective in providing speed limit compliance.

Master of Science / Civil Engineering / David R. Steward / With an increasing population, municipalities in the United States are struggling to secure safe, reliable water sources for future water demands. Alternative water sources are being considered to improve the overall water management picture. Wastewater reuse, reusing wastewater effluent for beneficial purposes, is an alternative water source that is gaining popularity in the United States. In this study a theoretical framework was developed to enable a region to quickly assess the feasibility of reusing wastewater for irrigation needs. Three criteria were established for the framework; they are, regulations and guidelines for reuse, adequate flow ratio, and cost benefit analysis. As a region moves through the framework and criteria a list of feasible wastewater facilities and end users are established. A model was developed for the cost benefit analysis based on regional input. As regulatory frameworks and economic factors evolve over time the model can be updated to assess how these changes will affect water reuse in a region. The model will provide a useful tool for a region to integrate wastewater reuse into the water resource management process. The Lower Arkansas River Basin (LARK) was highlighted by the Kansas Water Office as a region that should investigate the role of reuse in water conservation. Results from this report indicate 963 million gallons per year (MG/yr) of wastewater effluent could feasibly be used to irrigate 9 hole and 18 hole golf courses in the region. The results determined that any 18 hole golf course within a 15.9 mile radius of a wastewater treatment facility in the LARK could payback the capital costs for wastewater reuse within 10 years. This information is a useful tool for the region to start the discussion for implementing wastewater reuse in the region. The results from this report indicate wastewater reuse for golf course irrigation is economically feasible in the LARK. Establishing a safe reliable water source for the future is paramount to the future of Kansas. Future research is needed to determine how the wastewater diversion affects the environmental balance of the permitted discharge location.

Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Seismic hazards are a primary concern in some of the most populous regions in the United States. Performance-based seismic design has brought about new technology advances and introduced an innovative approach towards constructing seismic resistant buildings. Base isolation and structural damping systems are becoming increasingly utilized methods of advanced seismic resistance. This relatively new design approach presents various issues that must be addressed throughout the design and construction processes. A brief background on the origin, dynamics, and hazards of earthquakes and a discussion on designs of traditional, fixedbased structures is presented in this report. A description for selected types of new advanced seismic restraint systems, with an emphasis on base isolation, is also provided. Examples of current applications of buildings equipped with base isolation are presented. This report concludes with a review of the fundamental design methodology for structural base isolation along with additional requirements not addressed by the current building codes.

Doctor of Philosophy / Department of Civil Engineering / Yacoub M. Najjar / This study explored the potential use of ANNs for profiling and characterization of various environmental sites. A static ANN with back-propagation algorithm was used to model the environmental containment at a hypothetical data-rich contaminated site. The performance of the ANN profiling model was then compared with eight known profiling methods. The comparison showed that the ANN-based models proved to yield the lowest error values in the 2-D and 3-D comparison cases. The ANN-based profiling models also produced the best contaminant distribution contour maps when compared to the actual maps. Along with the fact that ANN is the only profiling methodology that allows for efficient 3-D profiling, this study clearly demonstrates that ANN-based methodology, when properly used, has the potential to provide the most accurate predictions and site profiling contour maps for a contaminated site. ANN with a back-propagation learning algorithm was utilized in the site characterization of contaminants at the Kansas City landfill. The use of ANN profiling models made it possible to obtain reliable predictions about the location and concentration of lead and copper contamination at the associated Kansas City landfill site. The resulting profiles can be used to determine additional sampling locations, if needed, for both groundwater and soil in any contaminated zones. Back-propagation networks were also used to characterize the MMR Demo 1 site. The purpose of the developed ANN models was to predict the concentrations of perchlorate at the MMR from appropriate input parameters. To determine the most-appropriate input parameters for this model, three different cases were investigated using nine potential input parameters. The ANN modeling used in this case demonstrates the neural network’s ability to accurately predict perchlorate contamination using multiple variables. When comparing the trends observed using the ANN-generated data and the actual trends identified in the MMR 2006 System Performance Monitoring Report, both agree that perchlorate levels are decreasing due to the use of the Extraction, Treatment, and Recharge (ETR) systems. This research demonstrates the advantages of ANN site characterization modeling in contrast with traditional modeling schemes. Accordingly, characterization task-related uncertainties of site contaminations were curtailed by the use of ANN-based models.

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / The older population (>65 years) numbered 36.8 million in the United States in 2005. By 2030, the number is estimated to be 71.5 million, almost twice as many. An increase in the older population means an increase in older drivers as well. As a result of the natural aging process, the possibility of older drivers being involved in crashes and sustaining severe injuries increases, according to past findings. The objective of this study was to identify characteristics of older drivers involved in crashes in Kansas as well as associated safety issues, which can be used to suggest potential countermeasures for improving safety. A detailed characteristic analysis was carried out for older, middle-aged, and younger drivers involved in crashes, using crash data obtained from the Kansas Department of Transportation, and comparisons were made among the groups. However, the characteristic analysis had no basis with regard to injury severity and hence, univariate statistical analysis was carried out to highlight these severities. In addition, a survey was conducted focusing on identifying older-driver behaviors, potential problems, and level of exposure to various conditions. From the severity analysis, it was found that injury severity of older drivers in crashes occurring on rural roads was significantly higher compared to those on urban roads. Therefore, a detailed analysis was carried out using the decomposition method and ordered probit modeling to identify contributing factors leading to the situation. According to the findings, the number of older male drivers involved in crashes was higher compared to older female drivers, even though older driver licensees’ data indicate the opposite. Most of the older-driver-involved crashes occurred under good environmental conditions and at intersections. A majority of older drivers had difficulties associated with left- turn maneuvering and preferred to avoid high-traffic roads and other demanding conditions. Exposure to inclement weather conditions and difficulties associated with merging, diverging, and identifying speeds and distance of oncoming traffic have lead to higher crash propensity. In rural areas, driving in the wrong direction, failing to comply with traffic signs and signals, and speeding were identified as frequent contributing factors in high severe crashes.

Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Trusses have been a common structural system for hundreds of years. The design and analysis of trusses evolved over time to its current state. Most manual truss analyses use the methods of joints and sections under idealized conditions. These ideal conditions, including pinned connections, cause discrepancies between the ideal truss being analyzed and the actual truss being constructed. The discrepancies include joint rigidity, connection eccentricity, and transverse loading. These cause secondary stresses, which induce bending moment into the truss members due to the chord’s continuity. Secondary stresses are most severe in continuous compression chord members. In these members, secondary stresses should be addressed to determine if they are severe and should be included in the truss design, or if idealized analysis will suffice. This report aims to determine the variables that affect the magnitude of secondary stresses in continuous compression chords due to chord continuity. The variables considered are chord stiffness, truss depth, and chord efficiency. Pratt trusses with WT chords were analyzed using the commercial analysis software RISA 3D. Pinned and continuous chord trusses were compared using the interaction value for each chord member. The results were used to determine how these variables affect secondary stresses and how secondary stresses can be predicted. Evaluation criteria were examined to determine the severity of secondary stresses. These criteria examine the radius of gyration, moment of inertia, depth, and section moduli of the chord members, and the moment of inertia of the truss for determination of secondary stress severity. The results of the studies show that secondary stresses increase with increasing member stiffness, decreasing member efficiency, and decreasing truss depth. The necessity for secondary stress consideration can be determined most accurately using the radius of gyration criterion (L/r[subscript]x < 50) for the compression chord.

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / Public transportation in rural America has existed for decades. Its providers are challenged with low populations and long distances in rural areas. Many of these rural transit providers have been in existence for many years, but ridership still remains low. These providers usually operate in a demand-response format, as opposed to large cities, where buses run on fixed routes. This research was conducted to see if any type of service improvements or enhancements could be found in order to increase ridership of demand-response transit service in rural Kansas. In order to determine if ridership of public transportation in rural Kansas can be increased, customer satisfaction surveys were conducted. One survey was distributed to current riders of demand-response systems, one survey distributed to non-riders of public transportation, and the last survey given to providers to obtain basic system information throughout Kansas. Ridership is significantly skewed toward the elderly, disabled, and those who either choose not to drive or are unable to drive. Those who do not fall into one of these three categories often do not use public transportation in rural areas. For most of the riders, public transportation is their only reliable method of mobility as they are transit dependent. Only 35% of the riders had a personal vehicle they could use to make the trip had public transportation not been available. Riders of demand-response transit systems in rural Kansas are pleased with the service provided as a whole. Non-riders are ambivalent toward demand-response transit service. They appreciate the fact that in many cases general public transportation service exist, but they are also generally unwilling to use it themselves. These are typically choice riders, and are unlikely to switch to demand-response transit due to their other mobility options. It was found that the more vehicles a person has access to in their household, the less knowledge they have about public transportation in their area. These people are content to use the vehicles they have, because it is more convenient than using public transportation in rural Kansas. Improvements to the provider’s system, like extending operating hours and days, along with implementing GIS-assisted scheduling may bring higher ridership. However, this may only increase the number of rides by the same current riders with few new riders grained. Increasing the usage of demand response ridership will continue to be a challenge in the future with the increasing number of elderly in the years to come.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / Wind pressures affect buildings of all shapes and sizes. Standards and codes have been published that instruct engineers and designers how to account for the wind loads interacting with structures. As further research on wind interaction with buildings is completed, more provisions and requirements are added to the codes and standards. At what point do the provision modifications and additions become more complicated than they need to be for a safe, effective building design? This report evaluates the progression of wind provisions through codes and standards since the early 1900’s. Then a detailed review of the current ASCE 7-05 Analytical Procedure design provisions is completed. Specifically, this report focuses on mid-rise structures 60 feet to 180 feet in height, located in the Midwest region of the United States. Following this in depth review of the ASCE 7 Standard, two studies are carried out. The studies were developed in order to assess the following two ideas: Have the wind load provisions become too complicated? Should there be a simplified procedure for mid-rise buildings?

Master of Science / Department of Civil Engineering / Kyle Riding / Fly ash is a by-product of coal-fired power plants. This material can be used as a partial cement substitute in portland cement concrete. Use of fly ash can improve concrete durability as well as utilize an industrial by-product that would otherwise be discarded in landfills. However, research on fly ash concrete has shown that in some cases, concrete with high volumes of fly ash can have deicer salt scaling problems. Salt-scaling is the flaking of a concrete surface that when severe enough may result in lower skid resistance and service life of the concrete. In this study, concrete mixtures with six different fly ashes were tested in a laboratory using the ASTM C 672 standard. Curing compound, a wax-based coating sprayed on the fresh concrete surface to reduce evaporation, was used to compare the effects of curing on salt scaling of concrete containing high volumes of fly ash. Different variables measured were the type of fly ash, curing conditions, and total paste volume included in the mix. Results showed that curing compounds will improve the salt-scaling resistance of concrete containing a fly ash that only marginally exhibits salt scaling. However, the salt-scaling performance of concrete that contains fly ash from a source that performs poorly in ASTM C 672 is not markedly improved by using a curing compound. Additionally, results showed that salt-scaling resistance of concrete containing fly ash performs better when the total paste volume is not increased by the addition of fly ash to the mixture. The Kansas Outdoor Concrete Exposure Site (KOCE) at the Kansas State University Civil Infrastructure Systems Laboratory (CISL) was constructed to compare laboratory results to actual field conditions in the future. The site was developed based on experiences from the University of Texas-Austin outdoor exposure site and the CANMET exposure site in Ottawa, Canada. Alika silica reaction blocks were made to develop the procedure for future concrete durability testing at KOCE.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / Strut-and-Tie models are useful in designing reinforced concrete structures with discontinuity regions where linear stress distribution is not valid. Deep beams are typically short girders with a large point load or multiple point loads. These point loads, in conjunction with the depth and length of the members, contribute to a member with primarily discontinuity regions. ACI 318-08 Building Code Requirements for Structural Concrete provides a method for designing deep beams using either Strut-and-Tie models (STM) or Deep Beam Method (DBM). This report compares dimension requirements, concrete quantities, steel quantities, and constructability of the two methods through the design of three different deep beams. The three designs consider the same single span deep beam with varying height and loading patterns. The first design is a single span deep beam with a large point load at the center girder. The second design is the deep beam with the same large point load at a quarter point of the girder. The last design is the deep beam with half the load at the midpoint and the other half at the quarter point. These three designs allow consideration of different shear and STM model geometry and design considerations. Comparing the two different designs shows the shear or cracking control reinforcement reduces by an average 13% because the STM considers the extra shear capacity through arching action. The tension steel used for either flexure or the tension tie increases by an average of 16% from deep beam in STM design. This is due to STM taking shear force through tension in the tension reinforcement through arching action. The main advantage of the STM is the ability to decreased member depth without decreasing shear reinforcement spacing. If the member depth is not a concern in the design, the preferred method is DBM unless the designer is familiar with STMs due to the similarity of deep beam and regular beam design theory.