"Each year many earth fill structures are designed and built with the primary purpose of impounding water. As these structures are only relatively impervious, engineers must consider the control of seepage in design. In order to predict seepage, the engineer must have knowledge of the potential flow or water through the earthen structure. He is, therefore, faced with the problem of determining a coefficient of permeability for use in design calculations.
The coefficient of permeability is easily enough determined for fine-grained materials. However, in construction it is very rare to find proper fill material which does not include quite a high percent of large aggregate. In most cases the removal of aggregate in the neighborhood of six inches, plus or minus, would raise the cost of construction too high to be reasonable. In design therefore the engineer is not faced solely with the problem of determining the coefficient of permeability for the fine material. Rather he is faced with the problem of determining an effective coefficient of permeability for the combined stone and fine-grained soil.
The research included herein was performed to study and evaluate the influence of large aggregates on the coefficient of permeability of single-grained soils. The results of the research are applicable to a large number of common engineering problems. Some of these problems are as follows:
(a) Often small levees are constructed at relatively low elevations. These levees are designed so as to be completely inundated at high water stages. Rapid drawdown of highwater can be a main factor in the instability of slopes, especially if the embankments are saturated. The permeability of the fill material, along with other data, is necessary for proper design of slopes.
(b) Determinations of seepage losses from small reservoirs is a problem often encountered by engineers. An effective value for the coefficient of permeability would be quite valuable.
(c) In large earth dams, flow nets can be used to determine the seepage loss, but a method for proper evaluation of the coefficient of permeability would be a helpful tool.
(d) In highway or railroad fills, it is often desirable to have a good value for the coefficient of permeability, so that proper drainage can be provided.
A complete study of the influence of large aggregate on permeability would involve the investigation of many different types of aggregate and fine-grained soils. This would necessitate expensive equipment and a large expenditure of time. Therefore, to place the research in the realm of practicality, both time and equipment wise, it was decided to confine the research to single-grained soils, with a large majority of the grain-size falling in the sand category. It was further decided to make use of limited aggregate sizes.
Tests are performed with three separate single-grained soils used as a matrix to surround coarse aggregate. Three coarse aggregate samples are used with two of the single-grain soils and one coarse aggregate sample with the third. An empirical equation for use in approximating the coefficient of permeability is formulated. Use of the empirical equation should be limited to the sand and the size aggregate tested. The equation is based on permeability of the matrix material with no aggregate present and is modified as the percent aggregate added increases"--Introduction, pages 1-3.
Heagler, John B., 1924-1999
Maxwell, James C.
Carlton, E. W.
Remington, Charles R., 1924-2013
Civil, Architectural and Environmental Engineering
M.S. in Civil Engineering
Missouri School of Mines and Metallurgy
v, 54 pages
© 1960 Edward Clayton Grubbs, All rights reserved.
Thesis - Open Access
Aggregates (Building materials)
Print OCLC #
Electronic OCLC #
Link to Catalog Record
Grubbs, Edward Clayton, "The evaluation of the influence of large aggregate on the permeability of single-grained soils" (1960). Masters Theses. 2677.