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Civil Engineering Reports

Permanent URI for this collection

https://hdl.handle.net/10217/100377

From 1947 to 1996, the Colorado State University Department of Civil Engineering issued reprints of engineering papers, bulletins, and documents as the series Civil Engineering Reports. University faculty and students authored most reports, and the department assigned report numbers in order of acquisition for each year. The series grew to more than 2,000 reports, of which nearly 1,300 are available in this digital collection.

Other CERs may be found in Mountain Scholar - Archives and Special Collections and in the Groundwater Data Collection.

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Browsing Civil Engineering Reports by Author "Albertson, M. L., author"

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    Artificial roughness standard for open channels
    (Colorado State University. Libraries, 1952-12) Robinson, A. R., author; Albertson, M. L., author; American Geophysical Union, publisher
    In the formulas in present use the resistance coefficient has been considered constant for a particular type of material in a particular state of upkeep. The resistance coefficient, however, is not a constant for a given channel but varies with both velocity and depth. From the nature of these formulas in present use, it may be seen that the variable influence of viscosity is not taken into consideration. Because of the need for more accurately determining the discharges in open channels a standard for roughness for open channels such as that which exists for pipes is desirable. The problem of developing a reproducible standard for roughness in open channels has previously received very little systematic study. Although several investigations have been made, each was made with a different type of roughness. This study was conducted for the purpose of determining whether an artificial roughness standard could be established for a channel with a boundary so rough that the viscous effects were negligible. The equation C = 26 .65 log10 (1.891 d/a) was established and is applicable over at least a fourfold variation in d/a and nearly a twofold variation in the resistance coefficient.
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    ItemOpen Access
    Flume studies using medium sand (0.45mm)
    (Colorado State University. Libraries, 1961) Simons, D. B., author; Richardson, E. V., author; Albertson, M. L., author; USGS, publisher
    The results pertaining to the progress during the first year of a comprehensive study of fluvial hydraulics, specifically roughness in alluvial channels, are presented. The report is based on the data collected by using a recirculating rectangular flume of adjustable slope, 8 feet wide, 2 feet deep, and 150 feet long with an alluvial bed of sand approximately 0. 7 foot deep. A typical river sand has been utilized. Its median diameter, d, is 0.45 mm and its relative standard deviation, σ, is 1.60. A total of 45 runs have been completed over a range of bed roughness forms extending from the plane bed with no movement to antidunes. In order to achieve this range, the discharge was varied from 2 to 21 cubic feet per second, the average velocity was varied from 0.5 to 7 feet per second, the average depth of flow was varied from 0.3 to 1.0 foot, and the slope of water surface was varied from 0.00014 to 0.01. Other variables measured included: water temperature, bed roughness, suspended sediment load, and total sediment load. Terms describing channel roughness were formulated and tested based on the data collected. The results indicate, as one possibility, that the Chezy coefficient of discharge in dimensionless form C/√g is a function of parameters involving the Froude number, viscosity of fluid, fall velocity, specific weight of the sediment, median diameter of the sediment particles and slope of the water surface. The various expressions presented were formulated on the fundamental concepts of fluid mechanics, dimensional analysis, and a detailed study of the variations of the variables measured. In the two regimes of flow the following forms of bed roughness were observed. For tranquil flow regime: plane bed without movement, ripples, dunes and transition from dunes to rapid flow forms. For rapid flow regime: plane bed with movement, standing sand waves, and antidunes. These forms of bed roughness are discussed and defined in various relationships. Other data of both a laboratory and a field nature were combined with the flume data to develop a graphical relationship in which the form of bed roughness is related to size of bed material.