Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / This report explores the requirements for the design and analysis of concrete containment and shows how newer material technologies such as self-consolidating concrete (SCC) and fiber reinforcement could assist in the constructability and durability of new nuclear power plant facilities. SCC for example, enables concrete to flow in the forms around the reinforcement and provides a more uniform adhesion with the reinforcement. Additionally, fiber reinforcement in the concrete mix increases bonding capability, thus making the concrete less likely to fracture. In particular, the ease of constructability benefits offshore floating nuclear power plants and preapproved modular power plants. To differentiate, the offshore plant would employ the assembly line to make all the plants the same while the modular plant, designed to be used anywhere, is not site specific and is typically smaller. Regarding research method, the report starts with the history of the nuclear industry in the United States, including the last nuclear power plant constructed, clarifying that nuclear energy was first harnessed for a submarine propulsion system before being employed to generate electricity. After these early endeavors, two major accidents, Three Mile Island (March 28, 1979) and Chernobyl (April 26, 1986), provided information regarding the lack of safety of nuclear power plant design and operation. Since the containment building is the focus of this report, recognizing the loads and the load combinations for design was the next step in research. Following that, the next step was to determine the design considerations and analyze the containment structure. New material technologies clearly have opened the door to new construction techniques, and the combination of new materials and methods offers structural engineers opportunity to build inherently safer nuclear power plants.

Doctor of Philosophy / Department of Civil Engineering / Stefan A. Romanoschi / Permanent deformation (rutting) is the most critical load-associated distress that develops on asphalt pavements significantly affecting their performance. Past research work focused on estimating permanent deformation of asphalt mixes using empirical prediction models or prediction models based on linear elastic material models. In recent years, mechanistic and mechanistic-empirical prediction models have been developed to take into account the behavior of asphalt material (viscoelastic, viscoplastic or elasto-visco-plastic). This research project aims to evaluate existing mechanistic models that predict permanent deformation (rutting) in asphalt mixes by comparing computed permanent deformation to that measured in a full-scale accelerated pavement test. Six pavement sections were constructed in the Civil Infrastructure Systems Laboratory (CISL) of Kansas State University with six different asphalt mixes. The sections were loaded with up to 700,000 load repetitions of a 22,000lb single axle. The transverse profiles at the pavement surface were measured periodically. For material characterization, asphalt mix samples fabricated in the laboratory, were subjected to dynamic modulus (|E*|), static creep - flow time (Ft), dynamic creep - flow number (Fn), triaxial and uniaxial strength tests, repetitive shear at constant height (RSCH) and frequency sweep at constant height (FSCH). The finite element software, Abaqus, was used to simulate and evaluate four permanent deformation prediction models, which are: creep model, elasto-visco-plastic model, viscoelastic model and Drucker-Prager model. The predicted permanent deformation was then compared to permanent deformation measured in CISL for the six of asphalt pavement sections. It was found that, with some improvements, creep and elasto-visco-plastic models could be used to predict permanent deformation in asphalt mixes. The viscoelastic model greatly under-predict permanent deformation, and the Drucker-Prager model with hardening criteria over predicts permanent deformation as compared to values measured in CISL.

Master of Science / Department of Civil Engineering / Mustaque A. Hossain / The objective of this research project was to assess the condition of general aviation airport pavements in Kansas. The study was also intended to form the basis for a pavement management system (PMS). A total of 137 runways from 107 airports across the state were surveyed. MicroPAVER, a PMS system developed by the U.S. Army Corps of Engineers, was selected as the platform for the PMS. An inventory database was developed for all runways in the network. Information about the construction and maintenance history was entered into the MicroPAVER database. On-site surveys were conducted between the months of May and July of 2008 to assess pavement conditions in terms of the Pavement Condition Index (PCI), following the methodology outlined by ASTM D 5340-04 and adopted by the Federal Aviation Administration (FAA). Approximately 68% of the sections surveyed were in “good” to “satisfactory” condition. Almost one-third of the network can be rated as “good.” About 21% of the sections studied were in “fair” condition. Overall, the condition of the network can be rated as “satisfactory.” A condition prediction curve was developed for each of the two different types of surfaces. From the prediction curves created using MicroPAVER, it was estimated that the number of branches rated as “good” could decrease by 50% by 2010. As much as 44% of the network could have a rating of “fair” by 2013 if the sections receive only routine maintenance. Two budget scenario comparison reports developed show that the 108 runways of the 78 general aviation airports eligible for FAA funding in Kansas could be brought to a “satisfactory” rating or above (i.e. average PCI ≥ 70) by spending approximately $15 million on average per year for the next five years.

Master of Science / Department of Civil Engineering / Sunanda Dissanayake / Rapid increases are estimated in the percentage of elderly among the U.S. population starting in 2010. A majority of the older Americans depend on automobiles to meet their transportation needs either because of lack of public transportation or by choice. Ninety percent of total trips made by the elderly are by personal vehicle and seventy percent of this number involves the elderly driving the vehicles. However due to the aging process, older drivers experience a natural decline in sensory, cognitive, and other mental and physical capabilities as compared to younger drivers. This situation, combined with an imperfect highway infrastructure is making older drivers one of the most critical groups in terms of highway safety, thus demanding safer driving conditions. Safety concern for older drivers arises when the fatality rate per mile driven is considered, as exposure is one of the crucial factors contributing to increased fatality risk of older drivers. Hence, exposure reported in Billion Vehicle Miles Traveled (BVMT) was considered for this study. Crash data and exposure data were used to compute the fatality rates. Sources for this data are the Fatality Analysis Reporting System (FARS) and National Household Travel Survey (NHTS). A basic characteristics study was completed to compare the fatality risk of younger (16-24 yrs), middle-aged (25-64 yrs), and older drivers (65+ yrs). Crash details were screened to study the characteristics of older drivers involved in fatal crashes. Risk for older drivers due to other involved drivers of all ages divided into groups was studied to understand their distribution. A number of statistical methods like the chi-square test of independence, odds ratio and double paired comparison estimates were applied to study contributing factors of older driver’s increased fatal crash involvement. Results from the characteristics study for the elderly indicate that a majority of fatal crashes occur under daylight conditions with relatively higher seatbelt usage and non-alcoholic driving on straight level roads, which are generally considered as safer driving conditions. Other factors studied include vehicle-related variables like body type; manner of collision; roadway-related variables like roadway function class, month of the crash, and day of the week; and driver-related variables like race. Roadway functional class, vehicle body type, travel speed, number of drunk drivers, and the month in which the fatality occurred were found to have strong correlation with age of the older driver. Results from paired comparisons were used to estimate the fatality risk of older occupants as drivers and passengers under two different conditions considered simultaneously. Older drivers were found to have more fatality risk compared to older passengers. Recommended measures are also discussed to enhance older driver safety in the U.S.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly W. Kramer / In 2006, a research project was being carried out by architects at architecture/engineering firm Cannon Design involving an optimum bay size for a hospital. RISA computer modeling was used to explore a set of lateral force resisting system (LFRS) options for a building based on this optimum bay size and importance category. The structural material was first narrowed down to steel, and then moment frames and braced frames are examined. The LFRS was narrowed down to braced frames, discarding moment frames due to their inordinate story drift. Of the different types of braced frames, the study further narrowed the LFRS system to chevron braced frames. Then the precise arrangement of braces for a particular building size using this bay system was examined. The steel material cost of the final system was compared to a system that only included members sized for gravity loads to demonstrate the rough amount of cost that a lateral system can add to a building.

Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Cold‐formed steel has become a preferred building material for wall framing in many different types of structures. One of its main uses has been as non‐structural members in curtain wall assemblies of structural steel framed buildings. In an exterior wall application, the main purpose of the curtain wall is to transfer out of plane loads to the steel frame while not supporting any superimposed gravity loads. Therefore, when the curtain wall is in the plane of the structural steel frame, the vertical deflection of the spandrel beam directly above the wall must be known to provide the appropriate deflection gap between the beam and the curtain wall so that gravity loads are not transferred to the wall. Common practice is to size the gap for the deflection from 100% of the live load. In some cases, the deflection gap may be significant, and since this gap must also be provided in the exterior cladding of the wall, it creates a design issue for the architect. This report presents the results of an investigation into the feasibility of reducing the size of the deflection gap when the wall is located directly under the spandrel beam. In this study, analytical models were developed for common design situations of curtain walls constructed of cold‐formed steel studs in structural steel framed buildings. This study investigates two common stud heights combined with different floor live loads. Taking into account that wall studs have some available axial compressive strength, a procedure was developed to determine an appropriate reduction for the gap. Using an iterative process a relationship is made between the axial compressive strength of the stud and the amount of axial load the stud can support to establish a factor which gives the percentage the live load gap for 100% live load can be safely reduced by.

Architectural Engineering / Department of Architectural Engineering and Construction Science / David R. Fritchen / Building Information Modeling (BIM) has been touted by industry leaders, professional societies and trade articles as the next ‘big’ industry trend shaping the delivery of commercial construction by architects, engineers and construction managers. BIM delivery has been presently utilized by over half of polled industry partners. And, withstanding a separate technological programming breakthrough, BIM will likely sustain high levels of growth in implementation in industry with the rise of the next generation of design and construction professionals and building owners in the next 50 years, making BIM delivery the primary means of commercial construction document and project delivery. Due to this growth and publicity, universities around the USA have been highly encouraged to implement BIM into their educational curricula fabric of course work, placing an ever increasing emphasis on a BIM skill set for their graduates. Taken together, surveys of Architectural Engineering programs current and planned implementation of BIM, potential employers’ emphasis on recruiting graduates with BIM skills, reading and referencing of trade articles relating BIM to industry delivery trends, research on initial and sustained requirements and associated costs of hardware and software for universities - specifically Architectural Engineering Programs to include BIM in their curriculum, this collation of research and information will trend towards suggestions and conclusions related to BIM’s importance in Architectural Engineering curriculum of the present and future.

Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Log construction is becoming increasingly popular throughout the U.S. Currently, seismic coefficients are not provided in model building codes for the design of the log shear walls as a lateral force resisting system for seismic forces. Current design practice is to use a response modification coefficient, R, of around 4.5. Several tests by other researchers on log shear walls showed strong energy dissipation and good lateral strength with stability after high displacements. This behavior of the log shear wall system is evidence that a higher R could possibly be used in design. The purpose of this study was to establish a response modification factor for single story log shear walls based on available shear wall tests using the definition of R provided in ATC-19. This research did not conduct testing according to the protocol and methodology of ATC-63. This work contains a history of the development of seismic design provisions in the U.S. and the evolution of the response modification coefficient. Common log construction practices are reviewed, with reference to ICC 400- Standard on Design and Construction of Log Structures. Using data provided by other researchers from physical testing and computer modeling of various types of log shear walls, an R of 6.0 is proposed based on the provisions of ATC-19. Finally, recommendations for further research to fully understand the behavior of the log shear wall system, including possible archetypes required by the methodology set forth in ATC-63, are provided.

Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Cold-formed steel has become a preferred building material for structural farming in many different types of structures, commonly for repetitive members such as floor joists, roof rafters, roof trusses and wall studs. For wood framed structures with repetitive members, a repetitive member factor increases the allowable bending stress from 1.00 to 1.50 times the reference design value, depending on both the type of material and the type of load. Currently, however, the bending strength of cold-formed steel repetitive members is not permitted to be increased, even though the method of framing is quite similar to that of wood except for the material properties. Typical light-frame wood construction consists of floor, roof, and wall systems, each with repetitive members connected by sheathing. A repetitive system is one of at least three members that are spaced not farther apart than 24-inches. These members must also be joined by a load distributing element adequate to support the design load. The behavior of the individual members, then, is affected by inclusion into this system. Additionally, the connected sheathing increases the bending capacity of bending members due to both composite action and load sharing. Composite action is a result of T-beam-like action between the repetitive member and connected sheathing, but is limited by nail slippage in the connection. Secondly, due to differential deflection between the members, sheathing is also able to distribute loads from weaker, more flexible members to the more rigid and stronger members. This effect is known as load-sharing. The same general principles of repetitive use should apply to cold-formed steel due to its similarity to wood construction. Accordingly, this paper conducts a preliminary study of the effects of both composite action and load-sharing in cold-formed steel assemblies and subsequently recommends using a repetitive member factor for cold-formed steel members.

Master of Science / Department of Civil Engineering / Eugene R. Russell / Pedestrian signals, particularly at signalized, mid-block crossing can cause delay to drivers after pedestrians’ have successfully crossed, which is termed “unnecessary delay” in this study. In many cases at a mid-block signal, a pedestrian pushes the button and then quickly crosses the street as soon as the walk signal appears and drivers still face several seconds of solid red ball and by law must remain stopped. On a busy street, a queue of vehicles waiting after all pedestrians have crossed can amount to hundreds of hours of unnecessary delay per year. The ‘Pedestrian Hybrid Beacon’ (Initially named a HAWK (High Intensity Activated Crosswalk)) Beacon was proven to be effective in decreasing this unnecessary delay when compared to standard signalized mid-blocks. The City of Lawrence, Kansas was interested in experimenting (as a HAWK beacon was considered experimental when they were installed) with a pedestrian hybrid beacon and they installed their first pedestrian hybrid beacon at a mid-block crossing on 11th street and a second pedestrian hybrid beacon at mid-block crossing on New Hampshire street, Lawrence, Kansas, which were the sites of interest for this research. A study was conducted at these sites to determine the effectiveness of the pedestrian hybrid beacon in decreasing the unnecessary delay to drivers by comparing it to a signalized mid-block crossing on Massachusetts Ave in Lawrence, Kansas. Apart from the delay measurements for these two sites, other parameters such as driver compliance rate to the signal, pedestrian compliance rate, and other driver and pedestrian characteristics were also studied. Video cameras were used to capture video at these sites and the effectiveness of the pedestrian hybrid beacon was analyzed from the video. The HAWK, now in the MUTCD as a Pedestrian Hybrid Beacon, proved to be effective in decreasing the unnecessary delay for drivers in this study. The City of Lawrence had a total of six pedestrian hybrid beacons in operation as per the information received in March 2010.