Engineering Commons^™

Analysis Of System Reliability As A Capital Investment, Albert J. Williams

Retrospective Theses and Dissertations

This report, "Analysis of System Reliability as a Capital Investment", is an analysis of radar system reliability of two similar tracking radar systems as a capital investment. It describes the two tracking radar systems and calculates the mission failures rates based upon field failure data. Additionally, an analysis of a simulation program written in FORTRAN is performed which treats system reliability as a capital investment based on 335 electronic systems that were fabricated with a reliability program versus 564 electronic systems fabricated without a reliability program. The data from the two tracking radar systems, one with reliability program and the …

The Application Of Limit Analysis To Shell Structures Using Existing Finite Element Analysis Codes, George G. Myers

Retrospective Theses and Dissertations

A ramjet inlet duct structure has been designed using nonlinear structural analysis to allow local plastic deformations which result in structural weight reduction. To establish the feasibility of reduced shell thickness, the Lower-Bound Theorem of limit analysis has been applied using an existing finite element analysis computer code intended for elastic analysis. The results of the analysis were verified by structural testing. Predicted stresses and deflections showed good correlation with measured values up to the point of failure. This work was supported by the U.S. Air Force Aero Propulsion Laboratory, Wright-Patterson Air Force Base, Ohio, under Contract No. F33615-72-C-1366.

A Possible Explanation Of Concrete Pop-Outs, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

This report summarizes several years of research relating to damage to concrete and aggregates undergoing freezing and thawing. Basic principles involving freezing and attendant pressures are considered. Application of these principles to the evaluation of concrete was accomplished in experiments on concrete having low and high air contents.

Freeze-thaw characteristics of saturated aggregates relative to physical properties such as porosity, absorption, and bulk specific gravity were studied by submerging individual particles in pre-chilled mercury. Pressures associated with pop-outs in concrete were monitored and are presented along with accompanying theoretical considerations.

Kentucky Research: A Flexible Pavement Design And Management System, Herbert F. Southgate, Robert C. Deen, James H. Havens, William B. Drake

Kentucky Transportation Center Research Report

Various strategies for designing pavement structures are discussed. Initial full-life design, stage designs and planned extensions of service life, final design, surface renewals for deslicking, no-defect designs for high-type high-volume facilities, and allowable-defect designs are considered. Economics enter in terms of salvage value of existing pavements and alternate designs using different proportions of materials within the structure.

The elastic model represented in Chevron's n-layered computer program is the basis for theoretical relationships. Ranges of values are given for input variables such as Young's moduli, Poisson's ratio, thicknesses for layers, tire pressure, and load. The Kentucky CBR is related to modulus …

Effect Of Pavement Texture On Traffic Noise, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

Noise from highway vehicles emanates primarily from engine exhausts, tire-pavement interaction) gears, and rattles. Studies have shown that at high speeds tires become the dominant generators of noise. Measurements on different road surfaces have produced different noise-versus-speed relationships (1). This led to the road surface adjustment used in the noise prediction procedure developed in NCHRP Report 117 (2). This adjustment called for a 5 dBA reduction for smooth surfaces (very smooth, seal-coated asphalt pavement) and a 5 dBA increase for rough surfaces (rough asphalt pavement with voids 1/2 inch (12 mm) or larger in diameter and grooved concrete). …

Highway Accidents At Bridges, Kenneth R. Agent, Robert C. Deen

Kentucky Transportation Center Research Report

Grade-separation structures (bridges) at interchanges, crossroads, over streams, railroads, etc., which are intended to provide greater convenience and safety, otherwise involve features which either obstruct the range of free travel or serve as containment barriers. The objective of this study was to identify those principal features of bridges and appurtenances which may be related to accident frequency and severity and to provide some further insights toward highway safety.

Pedestrian Accidents In Kentucky, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

When a pedestrian is hit by a motor vehicle, he is usually injured or killed; there is no protective cushion to absorb the impact. The high concentration of pedestrians in urban areas, coupled with heavy vehicle traffic, often results in large numbers of pedestrian accidents. In rural areas, there are considerably fewer pedestrians but traffic speeds are higher and, therefore, accidents are more often fatal.

Pedestrian fatalities have increased in the United States from about 7,800 in 1960 to approximately 10,500 in 1973 (1). There are 120,000 pedestrian accidents each year. Total traffic accidents in the US number about …

Speed Reduction In School Zones, Charles V. Zegeer, James H. Havens, Robert C. Deen

Kentucky Transportation Center Research Report

The use of flashing beacons together with signing has become somewhat standard throughout the country to alert drivers to the presence of school children and to regulate vehicle speed in school zones. Yellow beacons, usually two flashing alternately, may be used with both warning signs and regulatory signs. The only regulatory signs related to school zones are speed-limit signs. Both hazard identification beacons and speed-limit sign beacons are intended to operate only during hours when the warning and speed regulations are in effect. The effectiveness of signs and flashing lights in reducing speeds in school zones has been questioned.

The …

Optimal Highway Safety Improvement Investments By Dynamic Programming [Dec. 1974], Jerry G. Pigman, Kenneth R. Agent, Jesse G. Mayes, Charles V. Zegeer

Kentucky Transportation Center Research Report

The process of determining which projects to implement under a given budget, and which to defer until later, is central to the planning and management of highway systems. With a limited budget for construction, maintenance, and safety improvements, investments which will produce the optimal benefits must be chosen. This is often impossible to accomplish without the aid of a computer because of the complexity of the problem. Dynamic programming has been tested and verified as an efficient method for selecting priority projects to derive maximum benefits. The applicability of dynamic programming to the safety improvement program is demonstrated in this …

Accidents On Rural Interstate And Parkway Roads And Their Relation To Pavement Friction, Rolands L. Rizenbergs, James L. Burchett, John A. Deacon, Cass T. Napier

Kentucky Transportation Center Research Report

Friction measurements were made with a skid trailer at 70 mph (31 m/s) on 770 miles (1240 km) of rural, four-lane, controlled-access routes on the interstate and parkway systems in Kentucky. Each construction project was treated as a test section. Accident experience, friction measurements, and traffic volumes were obtained for each. Various relationships between wet-weather accidents and skid resistance were analyzed. Averaging methods were used as a means of developing trends and minimizing scatter. A moving average for progressively-ordered sets of five test sections yielded more definite results. The expression of accident occurrence which correlated best with skid and slip …

Identification Of Hazardous Rural Highway Locations, John A. Deacon, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

An effective procedure was determined for identifying hazardous rural highway locations based on accident statistics. Multiple indicators of accident experience that are necessary include the number of fatal accidents, the total number of accidents, the number of effective-property-damage-only accidents, and the accident rate. Critical levels of these four indicators should vary from state to state depending on the nature of the local safety improvement program as well as local traffic and roadway conditions and prevailing attitudes toward highway safety. Specific recommendations are given for use in Kentucky. Critical accident rates are established using quality control procedures.

To identify hazardous highway …

Evaluation And Modification Of The Traffic Noise Prediction Procedure For Kentucky Highways, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

Approximately 270 noise-level recordings were obtained at 39 highway sites and compared with the noise-level predictions obtained by the procedure outlined in NCHRP Report 117. The measured noise levels were computed in terms of the A-weighted L₁₀ value (level exceeded 10 percent of time) and then compared to the predicted noise levels. A significant discrepancy was found between predicted and measured noise levels; generally, the predicted values exceeded the measured values. Average error per location was 4.8 dBA; the maximum error was 13 dBA. A nomograph was devised to correct the predicted value; this nomograph involves observer-to-roadway distances, truck …

Fatigue Analysis From Strain Gage Data And Probability Analysis, Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

The Central Bridge over the Ohio River between Newport, Kentucky, and Cincinnati, Ohio, was completed in 1891 and in 1972-73 was considered to be in danger of fatigue failure. A series of investigations were undertaken to determine the likelihood of failure and to estimate the time of probable failure. During the investigation, a methodology was developed to determine fatigue damage from a probability analysis of traffic data by reconstituting or synthesizing the load (traffic) history of bridges. Strain gage data obtained with Prewitt scratch gages and SR-4 resistivity gages were used to evaluate fatigue damage incurred by the Central Bridge.

Experimental Portland Cement Concrete Shoulders Design And Construction, James H. Havens, Assaf S. Rahal

Kentucky Transportation Center Research Report

Kentucky's first portland cement concrete shoulder project was conceived in 1970 and was inspired by the Portland Cement Association's issue Concrete Shoulders for Safe Modern Highways, Concrete Report, 1970, and FHWA's Informational Memorandum CMPB-17-70, Experimental Project for the Evaluation of Portland Cement Concrete Shoulders Adjacent to Concrete Mainline Pavement; Project Prospectus, National Experimental and Evaluation Program; May 12, 1970. It was expected that at least two states in each region would participate in the national program. A 3.442-mile section of US 31 W, between Radcliff and Tiptop, beginning at the intersection of US 60 and extending southward, …

A Rock Classification Schema, Robert C. Deen, C. D. Tockstein, M. W. Palmer

Kentucky Transportation Center Research Report

The need for engineering data on earth materials for use in site selection, design, construction, and maintenance of major engineering structures is generally accepted. Probably the most pressing need is for such data to use in preliminary considerations of site selection and design alternatives. Maps and(or) surveys giving the areal distribution of earth materials and their characteristics, together with topographic maps available for many areas, would permit much preliminary work on engineering structures to be done without the engineer ever having to leave his office.

Heating The 9th Street Interchange, Louisville, Ky, James H. Havens

Kentucky Transportation Center Research Report

The 9th Street interchange, I 64-2(87)3, was first conceived about 1959. Preliminary design studies began in the early 1960's. Design began about 1964. The idea of heating the ramps was first considered in the early 1960's but was not pursued intently until the final design stage (about 1968). As the design progressed, it became more and more evident that snowing and icing conditions could prevent otherwise normal passage of traffic up and down the ramps. At one point on the structure, a combination of superelevation and grade would produce a 6 1/2 percent slope. The highest ramp or "fly over" …

High-Intensity Reflective Materials For Signs, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

Field observations and laboratory tests and evaluations were conducted on High-Intensity and Engineering Grade materials (Scotchlite), manufactured by the Minnesota Mining and Manufacturing Company, and were compared in regard to reflectivity, durability, and cost.

The High-Intensity Grade materials were found to have outstanding performance characteristics in comparison to Engineering Grade materials. The material significantly enhances sign legibility under low-beam illumination, and accelerated weathering tests showed superior durability.

Optimal Highway Safety Improvement Investments By Dynamic Programming [Aug. 1974], Jerry G. Pigman, Kenneth R. Agent, Jesse G. Mayes, Charles V. Zegeer

Kentucky Transportation Center Research Report

The process of determining which projects to implement under a given budget, and which to defer until later, is central to the planning and management of highway systems. With a limited budget for construction, maintenance, and safety improvements, investments which will produce the optimal benefits must be chosen. This is often impossible to accomplish without the aid of a computer because of the complexity of the problem. Dynamic programming has been tested and verified as an efficient method for selecting priority projects to derive maximum benefits.

There are several approaches to priority programming as it is related to the capital …

Before-And-After Analysis Of Safety Improvements On I 75 In Northern Kentucky, Jerry G. Pigman

Kentucky Transportation Center Research Report

In September 1971, the U.S. House of Representatives Subcommittee on Investigations and Oversight met in Covington, Kentucky, to discuss the accident experience and remedial procedures taken to alleviate the frequency of accidents occurring on approximately five miles of I 75 just south of Cincinnati. This section of highway had been and was continuing to be the subject of several safety improvements. The objective of this study was to conduct before-and-after investigations of the effectiveness of the following safety improvement projects: (1) five variable message signs within a two-mile section, (2) a New Jersey-type median barrier wall extending approximately four miles, …

Operational Characteristics Of Lane Drops, Don L. Cornette, Robert C. Deen, James H. Havens

Kentucky Transportation Center Research Report

Traffic behavior studies were conducted at seven lane-drop locations, representing three lane-drop classes. These studies consisted of conflict observations (that is, erratic movements and brakelight applications), spot-speed observations, and lane volume counts. Such a study was made before and after each different traffic control device installation in an attempt to determine which device was the most effective in minimizing conflicts at existing lane drops. A study of conflict deviations indicates that no single type of traffic control device studied was significantly effective in reducing erratic movement and brakelight rates at all seven lane-drop locations. Rather, it appears that different traffic …

Raised Pavement Markers As A Traffic Control Measure At Lane Drops [No. 418], Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

Raised pavement markers are an effective means of reducing erratic movements at lane-drop locations, particularly under nighttime driving conditions. The cost of raised pavement markers and their installation is nominal (approximately $150 per lane-drop location). It is recommended that raised pavement markers be installed at other lane-drop locations. Markers installed at locations described in this study have not been in place for a sufficient time to determine their durability; however, reports from other states indicate their durability is sufficient to render them economical. If raised pavement markers are installed routinely, steps should be taken to insure they are not damaged …

Porous Sand-Asphalt Mixtures, James H. Havens

Kentucky Transportation Center Research Report

Size is relative. Densely graded sand-asphalts are relatively similar to conventional, bituminous concretes. Porous sand-asphalts possess the same attributes as other porous, bituminous mixtures. Surely, sand-asphalt mixtures, can be designed to be as porous as the so-called, open-graded plantmix seals. Particle shape and texture otherwise define skid-resistance. Stability remains an assurance against scaling. Stability is assured by maximum utilization of filler-bitumen ratio and the stiffness of asphalt cement.

The Safety Barrier Dilemma, James H. Havens, Don L. Cornette, William M. Seymour

Kentucky Transportation Center Research Report

"Ran-off-the-road" fatal accidents currently account for approximately 65 percent of all freeway fatalities (1). Accordingly, ever-increasing emphasis has been given to the development of effective safety barrier systems, from guardrails to earth berms to median barriers to energy absorbing barriers and mires. However, highway designers have also recognized that safety barriers are hazards in themselves, misfits in the highway environment, and that they are items to be eliminated wherever possible. In a study of fatal accidents on the Interstate Highway System, it was found that fixed object collisions have been the leading source of fatalities, accounting for 43 percent …

Characteristics Of Outdoor Recreational Travel, Jerry G. Pigman, John A. Deacon, Robert C. Deen

Kentucky Transportation Center Research Report

The purpose of this investigation was to examine the characteristics of travel to outdoor recreational areas in Kentucky. Data were obtained by means of a license-plate, origin-destination survey at 160 sites within 42 recreational areas and by means of a continuous vehicle counting program at eight of these sites. A computer algorithm was developed for error detection and subsequent adjustment of the volume data as necessitated by occasional malfunction of the traffic recorders and vandalism. Vehicle occupancy was found to depend of the type of recreational area, distance traveled, and vehicle type. Occupancy increased with increasing distance and was greatest …

Elements Of Median Design In Relation To Accident Occurrence, Gordon R. Garner, Robert C. Deen

Kentucky Transportation Center Research Report

The purpose of this study was to compare the accident histories of different median types and to provide verification of generally recommended median widths and slopes. A major limitation of the analyses was the small number of possible combinations of median width and cross slope available for study.

The analyses reported provided evidence from accident histories to support the general requirement that wider medians are safer medians. It was indicated that medians should be a minimum of 30-40 feet wide for high speed facilities and that flat slopes should be provided; 4:1 slopes are inadequate for medians less than 60 …

Tar Concrete Pavement Construction And Performance, Jerry G. Rose

Kentucky Transportation Center Research Report

In 1969, a 6.6-mile section of relocated KY 15 in Perry and Knott Counties was paved utilizing coal-tar (RT-12) concrete base and surface. This project was authorized under the Appalachian Regional Development Act of 1965 and was designated as experimental as a means of implementing a section of the Act.

Two nearby sections of KY 15, containing asphalt (PAC-5) concrete base and surface, were designated as control sections and used for comparison purposes. With the exception of the bituminous material, the experimental and control sections were purposefully made equal in all other respects. A design soil CBR of 9 was …

A Pavement Design Schema, James H. Havens, Robert C. Deen, Herbert F. Southgate

Kentucky Transportation Center Research Report

Elastic theory and 40 years of empirical flexible pavement design in Kentucky have been joined into the design system presented herein. A brief discussion is presented of the coupling mechanisms relating experience to theoretical analyses. An annotated design procedure is presented as a guide for pavement designers. Design nomographs account for a wide range of input parameters and permit the designer a wide choice of alternative thickness designs.

Mercury-Filled Settlement Gage, Tommy C. Hopkins, Robert C. Deen

Kentucky Transportation Center Research Report

A description is given of a remote sensing, multiple-point, mercury-filled settlement gage designed for measuring in-place settlements. The gage consists of settlement units positioned at locations where settlement measurements are desired and a monitoring unit located outside of construction limits. Settlement readings are observed on a mercury manometer located at the monitoring site and are· equal to the differences in initial and subsequent pressure head readings. Comparisons of measurements obtained at a highway construction site from mercury gage settlement units and conventional settlement platforms are presented and show very good agreement. With the mercury gage, a large amount of settlement …

Spraygrip Anti-Skid Treatments, Kentucky Turnpike, Jerry G. Rose

Kentucky Transportation Center Research Report

No abstract provided.

Energy Absorption Devices, James H. Havens

Kentucky Transportation Center Research Report

An ironic consequence of modern highways has been the emergence of new types of accidents. Recent investigations (1) have shown that "running off the road" may be the largest, single cause of fatalities on limited access, multilane roads. According to the 1967 Report of the Special AASHO Traffic Safety Committee ("Yellow Book") (2) the rate of accidents in gore areas is approximately four times that of ran-off-the-road accidents at other locations. Gore areas which are not or cannot be modified to provide favorable terrain and unobstructed recovery zones have been recognized as misfits in the environs of the highway. Crash …