The state of roadside ditch design and performance has become a topic of concern for the Virginia Department of Transportation. Erosion failures of roadside ditches have occurred frequently enough to indicate that it may be desirable to revise the current design practice. Through the Virginia Transportation Research Council, VDOT has sponsored this research to investigate the state of design practice for these structures and to explore revisions to the design process resulting in a more economical design. To investigate the erosion problems, various VDOT personnel at each of Virginia's nine Construction Districts were interviewed with the intent to gain an understanding of roadside ditch performance in each District. When possible, field visits were made to sites experiencing erosion failure and soil samples were collected for analysis. In addition, experiences and design procedures in neighboring states were reviewed, with the objective of determining if similar problems have been experienced, and if so, how they have been addressed. The survey of other states included nine states, and a site visit to the Mount Airy District of the North Carolina Department of Transportation. A study of the literature relating to the hydraulic performance of unlined and lined ditches was also performed, with the objective of researching available stability criteria used in ditch design and determining if suitable values of Manning's n are being used in Virginia design. The results of this study presented in this thesis represent the best recommended roadside ditch design practice based on current available research. Recommendations include revisions to the current relationship of soil type and maximum allowable velocity, revisions to the application of Manning's n for various lining conditions, and suggestions to improve the overall design and construction process based on surveyed VDOT experience, surrounding states and current research. Future research will be necessary to improve the scientific bases for these recommendations / Master of Science

As America's infrastructure ages, many of the nation's bridges approach the end of their service life. In order to develop a method for handling the rising number of deficient and functionally obsolete bridges, nondestructive tests and evaluations must be undertaken. Valuable information from these tests regarding the strength and condition of bridges will help in making decisions about their rehabilitation and replacement. Two adjoining open spandrel reinforced concrete arch bridges in downtown Appalachia, Virginia were selected for live load testing by Virginia Department of Transportation (VDOT). Both bridges have supported an increasing amount of extreme coal truck traffic throughout their service life and are essential to the efficient transport of coal in the region. Because of their age, having been built in 1929, and the amount of visible damage and repairs, VDOT was concerned about their remaining capacity and safe operation. The live load tests focused on global behavior characteristics such as service strain and deflection as well as local behavior of the arches surrounding significant repairs. It was found that the strain and deflection data collected during load testing displayed linear elastic behavior, indicating excess capacity beyond the test loads. Also, given the loading applied, the measured strains and deflections were small in magnitude, showing that the bridges are still acting as stiff structures and are in good condition. Data collected during these tests was compared to results from a finite element model of the bridges to determine the coal truck size which is represented by the live load test loading configurations. The model comparisons determined the test loads produced comparable deflections to those produced by the target coal truck load. Through this approach, a recommendation was given to VDOT regarding the satisfactory condition of the aging bridges to aid in the process of load rating and maintenance scheduling for the two bridges. / Master of Science