Geology topics
J. V. Skinner
Publications and source records attributed to J. V. Skinner.
Laboratory data on coarse-sediment transport for bedload-sampler calibrations
A unique facility capable of recirculating and continuously measuring the transport rates of sediment particles ranging in size from about 1 to 75 millimeters in diameter was designed and used in an extensive program involving the calibration of bedload samplers. The facility consisted of a 9-footwide by 6-foot-deep by 272-foot-long rectangular channel that incorporated seven automated collection pans and a sedimentreturn system. The collection pans accumulated, weighed, and periodically dumped bedload falling through a slot in the channel floor. Variations of the Helley-Smith bedload sampler, an Arnhem sampler, and two VUV-type samplers were used to obtain transport rates for comparison with rates measured at the bedload slot (trap). Tests were conducted under 20 different hydraulic and sedimentologic conditions (runs) with 3 uniform-size bed materials and a bed-material mixture. Hydraulic and sedimentologic data collected concurrently with the calibration measurements are described and, in part, summarized in tabular and graphic form. Tables indicate the extent of the data, which are available on magnetic media. The information includes sediment-transport rates; particle-size distributions; water discharges, depths, and slopes; longitudinal profiles of streambed-surface elevations; and temporal records of streambed-surface elevations at fixed locations.
Progress report on temperature effects in vibrational-type sediment-concentration gages
No abstract available.
Characteristics and use of Helley-Smith type bedload samplers
Explore the source record for details and available documents.
Measurement of scour-depth near bridge piers
River-bed scour is a major source of damage to bridge piers and bridge abutments. When scour depth exceeds design limits, the supporting material around the footings is washed away and the structure becomes unstable. Equations for predicting scour-depth show a significant lack of agreement so portable equipment for measuring scour is needed. This report discusses the design of an instrumented, unmanned boat that (a) can be launched and controlled from a bridge and (b) can be maneuvered in flood flows that reach velocities of 15 feet per second. Calculations indicate the battery-powered propulsive system alone will weigh about 300 pounds and that the craft must be about 15-feet long. Because a free-running craft will be undesirably heavy and large, other methods of obtaining scour data are proposed. A tethered craft fitted with a controllable rudder and some methods of measuring scour at a point are presented for future study and development.
New approach to calibrating bed load samplers
Cyclic variations in bed load discharge at a point, which are an inherent part of the process of bed load movement, complicate calibration of bed load samplers and preclude the use of average rates to define sampling efficiencies. Calibration curves, rather than efficiencies, are derived by two independent methods using data collected with prototype versions of the Helley‐Smith sampler in a large calibration facility capable of continuously measuring transport rates across a 9 ft (2.7 m) width. Results from both methods agree. Composite calibration curves, based on matching probability distribution functions of samples and measured rates from different hydraulic conditions (runs), are obtained for six different versions of the sampler. Sampled rates corrected by the calibration curves agree with measured rates for individual runs.
Measuring the surface area of sediment particles in measurement and analysis of sediment loads in streams
No abstract available.