720 research outputs found

    A Chronicle of the Kentucky Transportation Research Program

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    The basis for the Kentucky Transportation Research Program (KTRP) was established more than 45 years ago and some of the current staff members have over 35 years experience in transportation research. Over the years, principal investigators have developed expertise in major areas of transportation and have made significant contributions in highway safety, pavement design and performance, embankment analyses, fatigue detection in bridges, noise abatement, traffic control and operations, voidless concrete, pavement texture and skid resistance, structural design and analyses of culverts, traffic forecasting, and numerous other areas. The Transportation Research Building houses several fully equipped laboratories. Special effort was made to provide flexibility and versatility in the arrangement of fixtures in the various laboratories. Computer services are available through the University of Kentucky and a full-time programming staff capable of summarizing, analyzing, and plotting data is available to all researchers. The Program also maintains a collection of current periodicals and publications from other transportation research organizations. Appreciable acceptance of study findings and resultant implementation of study recommendations has led to significant benefit-cost ratios for many studies undertaken by the unit. Values derived from research have been demonstrated routinely

    Performance Survey of Reinforced Concrete Pipe Culverts

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    Methods of installation and design criteria have tended to restrict the usefulness of rigid pipe culverts. With the increased mileage of highways which meet high standards, there has been an increase in the number of pipe culverts installed under high fills. This, of course, has accented the need for criteria for the proper design and installation of rigid pipe to obtain the maximum utilization of the pipe strength and to minimize the possible steelements that may occur in the road surface near the pipe installation or in the flow line of the pipe culvert. In order to provide for an efficient utilization of rigid pipe, the Department of Highways issued Standard Drawings and Amendments No. 15 and 16 to the 1956 Edition of Standard Specifications for Road and Bridge Construction specifying the bedding details and strength of pipe required for the various heights of fill. These standards were developed from the criteria set by the Bureau of Public Roads· The BPR criteria had been developed in co-operation with the American Concrete Pipe Association and was an attempt to bring together and simplify the prevailing methods of computing the necessary pipe strengths for the various classes of bedding commonly in use. Included in the Kentucky Standards was a provision permitting the use of the imperfect trench type of construction. Kentucky is, thus, one of thirteen states which permits this type of bedding, or a modification thereof. In order to evaluate the effectiveness of the design and construction criteria, the Bureau of Public Roads has requested that a number of reinforced concrete pipe installations be selected for periodic inspections. The data reported herein are a summary of the design and construction data for the pipes selected for study and a report of the condition of the pipes as observed during the first field inspection

    Rural Domestic Water System Peak Flows and Design Innovations, Optimal Water Planning Series

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    Planning engineers commonly use generous factors of safety for peak flow estimates in urban water supply systems both as a hedge against unforeseen growth and because economies of scale result in relatively low user costs even with such reserve capacity. Transplanting of such design criteria into the rural setting, however, simply does not work. The low density portions of rural domestic systems require very realistic design criteria or the construction costs become infeasible for the small number of customers involved. Peak instantaneous flow rates in a Utah rural system were measured continuously during two summers on three dead-end lines serving various numbers of customers. The second summer included measurement of flows to customers whose maximum flow rate was limited by a simple orifice placed in each meter. Conclusions which emerged from this study included: 1) Actual peak demands were lower than those required for design purposes by some state regulatory agencies, but higher than the Farmers Home Administration minimum standard. 2) Where extremely small mains are required by the economics of low density situations, or where unforeseen growth is overtaxing system capacity, peak demands can be cut significantly by simple, flow restricting devices at each meter without decreasing the quality of water service to the customer. 3) Field measurements of head loss through 10 year old plastic pipe indicated a Hazen Williams friction factor average of 133

    Tidal Flexure of Jakobshavns Glacier, West Greenland

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    Jakobshavns Glacier, a floating outlet glacier on the West Greenland coast, was surveyed during July 1976. The vertical displacements of targets along two profiles perpendicular to the fjord wall bounding the north margin of the glacier were analyzed to determine the effect of flexure caused by tidal oscillations within the fjord. An analysis based on the assumption that vertical displacements of the glacier reflected pure elastic bending yielded the conclusion that the effective thickness of the ice (i.e., the thickness which remained unaffected by surface and basal cracking and which behaved as a continuum) was ∼160 m 2.6 km upglacier from the calving front and ∼110 m 0.6 km from the calving front. An analysis based on the more realistic assumption that observed bending reflected elastic and viscoplastic deformation yielded the conclusion that the average effective thickness of the ice was 316 ± 74 m (∼40% of the estimated 800-m total thickness) 2.6 km from the calving front and 160 ± 48 m (∼21% of the estimated 750-m total) 0.6 km from the calving front. A constitutive relationship appropriate for hard glide during flexure was used

    Geotechnical, Hydrologic, and Hydraulic Investigation of Mill Creek Dam-Phase II

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    The general scope of this study, Phase II, was to assess the safety of Mill Creek Dam. Findings obtained from detailed geotechnical, hydraulic, and hydrological investigations are presented. The structural stability, as well as the hydrological and hydraulic stability, were investigated. Specifically, objectives of the study were as follows: 1. To determine the engineering characteristics of the clay core, shells, and random fill. 2. To evaluate the potential for piping. 3. To evaluate seepage conditions at the site. 4. To evaluate the structural stability of the earth and rockfill dam. 5. To evaluate erodability. 6. To assess geologic conditions at the site. 7. To evaluate existing and required spillway hydraulics and hydrology of the site. 8. To analyze requirements for a drawdown facility. 9. To evaluate alternative remedial measures that could be used to correct deficiencies in the dam. This study presents data relating to the degree of safety and alternative remedial schemes. Information presented herein will aid in the final selection of the remedial method and in implementing remedial construction. Development of detailed remedial plans, however, was not within the scope of this study

    Investigation of Collapse of Long-Span Structure Under KY 80 in Floyd County

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    The Kentucky Transportation Research Program (KTRP) was requested to obtain and review design, construction, and post construction documents relative to the long-span structure under KY 80 in Floyd County. Telephone and in-person contacts were made with various agency officials involved with the structure in an endeavor to collect pertinent data. Documents that were initially presented to KTRP staff were thoroughly reviewed and a draft report based upon information submitted was prepared. The draft report included a scenario relating to a probable sequence of events that could have been significant in the ultimate collapse of the structure. Soon after distribution of the draft report and during the time of its review, additional information was forthcoming, and an Addendum was prepared and is included herein. Another probable cause of failure is included in the Addendum

    Review of Pertinent Contract Documents Tennessee-Tombigbee Waterway Divide Cut Section 3A

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    During construction of a portion of the Tombigbee Canal near Corinth, Mississippi, southward from Pickwick Lake (Station 13,118+00 to 13,337+50), the Contractor reported various problems, which he termed differing site conditions. Some of the items considered as problems by the Contractor were: the amount of cherty Paleozoic material was far less than he expected or anticipated, there were deep deposits of bluish muck, the alluvial was not sufficiently stable to place in 1-foot lifts, excessively wet materials made it necessary to shift equipment frequently, the equipment had to travel over bad roads, and the materials had no bearing strength
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