Engineering Commons^™

Evaluation Of Triaxial Testing Equipment And Methodologies Of Three Agencies, Tommy C. Hopkins, David L. Allen

Kentucky Transportation Center Research Report

To obtain reliable and consistent shear strength results, which are essential in the design of earth structures, from triaxial tests, careful attention, skill, and judgement must be given to testing procedures and equipment make-up. There are many sources of potential errors in the test, especially when pore pressures are monitored. Consequently, a question inevitably arises concerning tbe quality of triaxial test results obtained by different geotechnical laboratories. The intent of this study was to initiate and help establish a triaxial testing forum whereby any geotechnical laboratory engaged in triaxial testing can check the quality of their triaxial results, and therefore, …

Corrective Measures For Unstable Bridge-Approach Embankment Us 68, Licking River, Blue Licks, E. Gregory Mcnulty

Kentucky Transportation Center Research Report

In January 1979, an in-depth investigation of the unstable bridge-approach embankment, Figure 1, on US 68 over the Licking River in the north central portion of Nicholas County (MP 91-68-B0027) was begun by the Division of Research. This investigation was a continuation of a project initiated by the Division of Materials in 1967. This site is approximately 0.3 miles (0.5 km) north of Stony Creek Road and approximately 7.5 miles (12.0 km) north of Carlisle and 0.8 miles (1.3 km) southwest of Blue Licks Battlefield State Park. The bridge is a three-span, continuous, welded plate girder structure with span lengths …

Seasonal Variations In The Skid Resistance Of Pavements In Kentucky, James L. Burchett, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

Frequent measurements of skid resistance were made on 20 pavements in common use in Kentucky. Tests were conducted from November 1969 through 1973. Principal analysis involved relating changes in skid resistance to day of the year and relating skid resistance to temperature at the time of test, to average antecedent temperatures, and to average rainfall.

Seasonal variations exhibited an annual sinusoidal cycle. The changes in sand-asphalt and bituminous concrete surfaces under higher volumes of traffic were about 12 skid numbers. The changes in portland cement concrete and bituminous concrete under lower volumes of traffic were about 5 skid numbers. The …

Truck Design And Usage And Highway Pavement Performance, Robert C. Deen, Herbert F. Southgate

Kentucky Transportation Center Research Report

When the term highway pavement is used, most people think of the moderate to thick systems on which their vehicles travel on intermediate- or high-type roadways. These pavement systems are typically constructed of bituminous concrete or portland cement concrete. This is not to say that low-volume roads do not have a pavement system; however, in case of low-volume roads, the pavement system usually consists of unbound aggregates, sod, soil materials, or at the most very thin or moderate applications of a binding material. It is the high-type pavement systems to which the comments in this paper will be addressed specifically. …

Cracking In Concrete Pavement, Robert C. Deen, James H. Havens, Assaf S. Rahal, Wm. Vernon Azevedo

Kentucky Transportation Center Research Report

Cracking of portland cement concrete pavements is a common, even expected, occurrence. To minimize potentially detrimental effects, it is necessary to understand mechanisms that might be used to explain such behavior so that measures may be developed and implemented to control the occurrence of such cracking. Several "theories" are discussed that might provide the mechanisms of pavement cracking. An alternate meachanism, based on fatigue loading of the concrete by temperature expansions-contrations, for the development of so-called D-cracking is offered.

Cost-Effectiveness Of Lane And Shoulder Widening Of Rural, Two-Lane Roads In Kentucky, Charles V. Zegeer, Jesse G. Mayes

Kentucky Transportation Center Research Report

The purpose of the study was to determine the cost-effectiveness of widening lanes and shoulders on rural, two-lane roads. Information concerning geometries, accidents, and traffic volumes was obtained for over 15,000 miles (25,000 km) of roads. Reductions in accident rates occurred as lane and shoulder widths increased. Run-off-road and opposite direction accidents were the primary accident types associated with narrow lanes and shoulders. Reductions in accidents ranged from 10 to 39 percent for lane widening and 6 to 21 percent for shoulder widening. Priority listings were prepared for 531 projects based on critical rate factor. Priority listings were also prepared …

Development Of Warrants For Left-Turn Lanes, Kenneth R. Agent

Kentucky Transportation Center Research Report

Warrants for the installation of separate left-turn lanes were developed. Literature was reviewed, and policies and practices in other states were surveyed. Accident analyses of locations with and without separate left-turn lanes were conducted. Computer simulation was used to determine the relationship between and among traffic delay and load factor and traffic volume, percent left-turns, cycle length, and cycle split. The relationship between left-turn accidents and conflicts was investigated.

Warrants were developed involving the following three general areas: (1) accident experience, (2) volumes (based on delay), and (3) traffic conflicts.

Statewide Survey Of Skid Resistances Of Pavements (1978), Rolands L. Rizenbergs, James L. Burchett

Kentucky Transportation Center Research Report

Statewide survey of skid resistances continued in 1978 with the testing of 2,943 miles (4,736 km) of state primary roads and 2,405 miles (3,870 km) of state secondary roads. About 10 percent of both the state primary mileage and the state secondary mileage had an average skid number of 28 or less. These pavements, in pariticular, should be considered for de-slicking.

In 1977 and 1978, 35 percent of the mileage of rural, state-maintained roads in Kentucky were surveyed. These roads carried 87 percent of all traffic on rural, state-maintained roads.

Delineation Of Stop-Sign Approaches, Kenneth R. Agent

Kentucky Transportation Center Research Report

The objective of this study was to use new types of delineation at a stop approach to determine if drivers could be made more aware of the "Stop" situation ahead. The treatments involved post delineators, raised markers, and transverse striping placed at various spacings in advance of the "Stop" signs. Speeds were measured 200 feet (61 m) and 1,200 feet (366 m) in advance of the "Stop" sign. Brakelight distances were also recorded.

The various delineations provided significant reductions in speeds. Post delineators in combination with transverse stripes were the most effective. No significant difference was found between results obtained …

Raised Pavement Markers At High-Hazard Locations, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

Even though a large number of potentially hazardous locations exist on rural, two-lane roads, guidelines have not been developed for use of raised pavement markers under night and during adverse weather conditions. The purpose of this study was to evaluate the use of raised markers at a sharp curve and narrow bridge in Kentucky. Visual observations, speed data, encroachment data, and accident data were used to evaluate the effectiveness of the markers.

Extensive visual observations of the sharp curve and narrow bridge in this study have provided data to support recommendations for improved delineation at similar sites on rural, two-lane …

Kentucky Culvert Study: An Engineering Review Of Policies And Practices Related To Procurement Of Culvert And Sewer Pipe, Byrd, Tallamy, Macdonald And Lewis

Kentucky Transportation Center Research Report

Objectives: This study was undertaken to provide the Kentucky Department of Transportation (KyDOT) with 1 ) information concerning the present state-of-the-art in the selection of culvert pipes with reference to the problem of drainage water from coal mines, shales and other excavations which may be highly acidic; and 2 ) recommendations on alternative materials and/or special treatments for pipes in areas of acid drain water.

Methodology: The study consisted of a review of the literature from selected highway agencies including Kentucky, a review of culvert pipe selection practices in other states and discussions with persons knowledgeable about pipe materials.

Findings: …

Road Rater And Benkelman Beam Pavement Deflections, Gary W. Sharpe, Herbert F. Southgate

Kentucky Transportation Center Research Report

The Benkelman beam has been one of the most commonly used methods of measuring surface deflections of a highway pavement. A Benkelman beam is based on a simple lever-arm principle and uses dial guages to measure surface deflection under an applied load. In 1971, the Commonwealth of Kentucky purchased a Road Rater for use by the Department of Transportation, Division of Research. The Road Rater applies a sinusoidal force to the pavement at a fixed frequency; surface wave velocities are measured and electronically integrated to obtain surface deflections, Since 1971, work has progressed toward the development of a pavement evaluation …

Problem Identification For Highway Safety Plan, Jerry G. Pigman, Kenneth R. Agent

Kentucky Transportation Center Research Report

To comply with Section 402, Title 23 of the United States Code, each state is required to prepare a annual highway safety program. Kentucky's program, which includes identification, programming, budgeting, and evaluation of highway safety projects, is intended to have a positive impact on the reduction of traffic accidents. The first step in the program, problem identification, requires systematic, statistical analyses of accident records. In-depth analyses of accident data were performed, and 25 problem areas were investigated. Accident rates were found for counties and cities in the following categories: total accidents, fatal accidents, accidents by driver age and sex, and …

An Evaluation Of Permissive Left-Turn Phasing, Kenneth R. Agent

Kentucky Transportation Center Research Report

In this study, exclusive left-turn phasing was replaced with permissive left-turn phasing at four trial intersections. Delay and accident studies were done before and after the trial installations. Also, a questionnaire was issued to determine public opinion concerning the signals.

The use of permissive-turn phasing resulted in a 50-percent reduction in left-turn delay and a 24-percent reduction in total delay compared to exclusive phasing. The permissive left-turn phasing did result in an increase in left-turn accidents. Other accident types, such as rear-end accidents, did not change. The number of left-turn accidents decreased as drivers became more familiar with the signals. …

The Effectiveness Of Regulatory School Flashers In Reducing Vehicle Speeds, Charles V. Zegeer, Robert C. Deen

Kentucky Transportation Center Research Report

Pedestrian safety for school-age children has been a growing problem in recent years. Children between the ages of five and nine represent less than 10 percent of Kentucky's population but over 16 percent of all pedestrian fatalities. A study was conducted to evaluate the effectiveness of regulatory school flashers used in school zones to reduce vehicle speeds and alert motorists of pedestrian activity and to determine measures which promote safety in school zones.

Speed studies were conducted during flashing and non-flashing periods at 48 school zones where regulatory school flashers were used. The locations involved a variety of speed limits …

Fatigue Damage Of Flexible Pavements Under Heavy Loads, James H. Havens, Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

A modified Chevron N-Layer computer program has the capability of calculating the "work" done by the total load on a given load group. Earlier analyses of AASHO Road Test sections and test vehicles had permitted the development of damage factor relationships. This paper presents seven, namely two-tire and four-tire single axles, tandems, triaxles, and four-axle, five-axle, and six-axle groups. The two-tire axle (front or steering axle) has the most severe damage relationship. The 80-kN (18-kip) four-tire single axle was used as the reference axle and was assigned a damage factor of 1.0 for a specific amount of "work". Other axle …

Interstate Safety Improvement Program, Jerry G. Pigman, Kenneth R. Agent, Charles V. Zegeer

Kentucky Transportation Center Research Report

A previous report dealt with development of procedures for preparation of an Interstate Safety Improvement Program. The purpose of this report was to prepare prioritized rankings of recommended improvements which could be implemented for the Interstate Safety Improvement Program. Together, these two reports include logical and comprehensive procedures for the selection, scheduling, construction, and evaluation of highway safety improvement projects.

Considerable detail is presented which documents analysis procedures used to determine sites, sections, and elements of the roadway in need of improvement. The average number of accidents per interchange, bridge, 1.0-mile (1.6-km) section, and 0.3-mile (0.48-km) spots were summarized for …

Use Of Economic Analyses And Dynamic Programming In The Selection Of Projects For Resurfacing, Charles V. Zegeer, Kenneth R. Agent, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

The objective of this study was to develop a dynamic programming procedure using economic analyses to assist in optimizing expenditures in the pavement resurfacing program in Kentucky. Benefit relationships were determined from expected accident reduction, improved comfort, time savings, fuel savings, and maintenance savings. The only cost input to the program was the resurfacing cost of each project.

Dynamic programming was adapted to the selection of projects for resurfacing. Over $8.4 million of additional user benefits would have been realized in 1976 if dynamic programming had been used in selecting projects. The benefit-cost ratio of sections selected for resurfacing was …

Final Report On Project Feasibility : To Jacksonville Transportation Authority, November, 1979, Parsons Brinckerhoff, Flood &. Associates

Jacksonville and Duval Co. Miscellaneous

This report was prepared for the purpose of determining the feasibility of the DPM for the Jacksonville CBD. The gathering of data, the preparation of information, the research, the citizens' participation, the alternatives analysis, and the detailed planning were all done for the purpose of answering one basic question: Is a downtown people mover feasible for Jacksonville?

Acoustic Emission Monitoring Of Weldments, Theodore Hopwood Ii, James H. Havens

Kentucky Transportation Center Research Report

Weld tests were performed on low-carbon and high-strength, low-alloy steel weldments. The weldments were monitored with an acoustic emission detector during both the 'in-process' and the 'in-cooling' phases of the welding operation. Artificial defects were induced in several of the welds to promote cracking. Some high-strength weldments were designed to produce welds subject to high restraint.

Nondestructive and destructive evaluation of the completed weldments revealed that high acoustic emission activity 'in-cooling' could be correlated with embedded defects and cold-cracking. Copious emission activity was also detected from unflawed weldments. Acoustic emissions were detected in high-strength steel weldments for periods up to …

Low-Void Concrete Mixtures, Assaf S. Rahal, James H. Havens

Kentucky Transportation Center Research Report

The purpose of this study was to modify concrete mix-design formulas to supplant all water over and above that needed for hydration with a non-evaporable liquid material and(or) a super-water-reducer or plasticizer -- thus producing a low-void concrete. A water-cement ratio of 0.244 - 0.30 was presumed minimal for hydration of the cement. Several polymeric materials, asphalts, oils, and superplasticizers were used. Success was achieved with two latexes, one epoxy, and several superplasticizers. The use of these materials in concrete resulted in improved strength, reduction of air voids and permeability, and enhancement of resistance to corrosive chloride salts.

Priority Programming For Highway Reconstruction, Charles V. Zegeer, Rolands L. Rizenbergs

Kentucky Transportation Center Research Report

An adequacy-rating procedure was developed for use in priority programming for highway reconstruction. The procedure makes use of 15 roadway and traffic elements to rate highway sections in urban and rural areas based on 100 points. Condition elements (35 points) include a subjective rating of highway foundation, pavement surface, drainage, and maintenance economy. Safety elements (35 points) are stopping sight distance, highway alignment, skid resistance, accident experience, and traffic control devices. Service elements (30 points) include shoulder width, passing opportunity, rideability, surface width, volume/capacity ratio, and average speed.

Some of the advantages of the new procedure include computerized analysis of …

Seatbelt Usage In Kentucky [Nov. 1978], Kenneth R. Agent, Michael Barclay, Robert C. Deen

Kentucky Transportation Center Research Report

In this report, the effectiveness and usage of seatbelts in Kentucky and factors affecting usage are examined and identified. Data were obtained from three sources: field observations, accident reports, and a questionnaire.

Kentucky drivers and passengers were found to have lower seatbelt usage rates (slightly under 10 percent) than drivers and passengers in other states. The accident data showed that the chances of being killed or severely injured is greatly reduced by wearing a seatbelt. Seatbelts reduced the chance of being killed by a factor of six and the chance of being severely injured by a factor of two. Several …

Design System For Asphaltic Concrete Overlays, Herbert F. Southgate, Gary W. Sharpe, Robert C. Deen

Kentucky Transportation Center Research Report

A method of designing asphaltic concrete overlays has been developed from (1) Kentucky's theoretical design curves, (2) an estimate of future traffic and the associated fatigue (five procedures are presented according to types of information available), (3) strength of subgrade on subject project (laboratory CBR tests or results of dynamic in-place tests such as the Road Rater), and (4) present condition of the existing pavement (from dynamic in-place tests, roughness measurements, or present serviceability index). Deterioration has been expressed as reduced or effective thicknesses of new-quality materials producing the same measured dynamic deflections. The total thickness required for the future …

Analysis Of Weekday, Weekend, And Holiday Accident Frequencies, Jerry G. Pigman, Rolands L. Rizenbergs, Donald R. Herd

Kentucky Transportation Center Research Report

On rural roads, the largest number of accidents have occurred on Saturdays, Fridays, and Sundays, respectively. Tuesdays generally had the lowest number of accidents. The highest accident rates for two-lane roads were on Sundays and Saturdays, and the rates for expressways (interstates and toll roads) were the highest on Sundays. Accident rates on weekends were substantially higher than on weekdays. Rates of fatal and all accidents were lower during holiday periods than during weekends not involving holidays. Holiday periods had fewer accidents per day than weekends but had more accidents per day than weekdays. Traffic during holidays, however, was significantly …

Statewide Survey Of Skid Resistances Of Pavements [Nov. 1978], Rolands L. Rizenbergs, James L. Burchett

Kentucky Transportation Center Research Report

In 1969, a research-type, skid-test trailer was acquired, U.S. routes were surveyed in 1970 and 1971, and the interstate and toll-road systems were surveyed in 1971. The data were used for research purposes and have been reported. The interstate and toll-road systems were surveyed again for research purposes in 1974. Since October 1974, surveys have been performed under highway safety project grants (interaccounted to 108, subsection OSKID). Primary and principal secondary roads, involving 4,613 miles (7,427 km), were surveyed in 1975. A second skid tester, a survey-type, was acquired in April 1976; and survey-testing of major, rural collector roads continued …

Pavement Evaluation Using Dynamic Deflections, Gary W. Sharpe, Herbert F. Southgate, Robert C. Deen

Kentucky Transportation Center Research Report

Dynamic test deflections have been duplicated by elastic theory using the Chevron N-layered computer program. Dynamic surface deflections obtained using the Road Rater have been used in conjunction with elastic theory to analyze pavement behavior. A procedure has been developed to use field measured Road Rater deflections to estimate the elastic moduli of the foundation material and to determine the equivalent thicknesses of new material which approximate the behavior of the structure. The estimated moduli and (or) equivalent thicknesses may be used as inputs to design overlay thicknesses. An analysis of the deflections of the first three sensors of the …

Warrants For Left-Turn Signal Phasing, Kenneth R. Agent, Robert C. Deen

Kentucky Transportation Center Research Report

Warrants for the installation of left-turn phasing were developed. A review of literature was conducted along with a survey of the policies of other states. Field data of delays and conflicts were taken before and after installation of exclusive left-turn signalization. Left-turn delay studies were conducted at intersections with varying volume conditions. Analysis of the effect on accidents of adding a left-turn phase was made. The relationship between left-turn accidents and conflicts was investigated. Other types of analyses concerning gap acceptance, capacity, and benefit-cost ratios were also performed.

It was found that exclusive left-turn phasing significantly reduced left-turn accidents and …

A Rational Thickness Design System For Asphaltic Concrete Overlays, Herbert F. Southgate, Gary W. Sharpe, Robert C. Deen

Kentucky Transportation Center Research Report

A method of designing asphaltic concrete overlays has been developed making use of (1) Kentucky's proposed design curves, (2) an estimate of future traffic and the associated fatigue (five procedures are presented according to types of information available), (3) strength of subgrade on subject project (laboratory CBR tests or results of dynamic in-place tests such as the Road Rater), and (4) present condition of the existing pavement (from dynamic in-place tests, roughness measurements, or present serviceability index). Deterioration was expressed as reduced thicknesses of new-quality materials producing the same measured dynamic deflections. The total thickness for the predicted traffic minus …

Simulation Of Travel Patterns For Small Urban Areas, Jerry G. Pigman, Robert C. Deen

Kentucky Transportation Center Research Report

The objective of this study was to develop models which would simulate internal-external trips and external-external (through) trips. Regression analysis and cross-classification of data were tested in an attempt to predict the number of internal-external trips and the percentage of through trips. Regression analysis was used in the development of a through-trip distribution model. Grouping data for analysis created some problems; however, trial-and-error evaluation enabled selection of variables which produced reasonable results. Variables found to be most significant in the development of internal-external models were population and employment. For through-trip models, variables used were population, functional classification, AADT at the …