Transactions of the American Society of Civil Engineers, vol. LXXII, June, 1911

AMERICAN SOCIETY OF CIVIL ENGINEERS INSTITUTED 1852
Paper No. 1192
By William Cain, M. Am. Soc. C. E.
With Discussion by Messrs. J. R. Worcester, J. C. Meem, and William Cain.
The most extended experiments relating to retaining walls are those pertaining to retaining walls proper and the more elaborate ones on small rotating retaining boards. The results referring to the former agree fairly well with a rational theory, especially when the walls are several feet in height; but with the latter, many discrepancies occur, for which, hitherto, no explanation has been offered.
It will be the main object of this paper to show that the results of these experiments on small retaining boards can be harmonized with theory by including the influence of cohesion, which is neglected in deducing practical formulas. It will be found that the influence of cohesion is marked, because of the small size of the boards. This information should prove of value to future experimenters, for it will be shown that, as the height of the board or wall increases, the influence of cohesion becomes less and less, so that (for the usual dry sand filling) for heights, say, from 5 to 10 ft., it can be neglected altogether.
The result of the investigation will then be to give to the practical constructor more confidence in the theory of the sliding prism, which serves as the basis of the methods to follow.
Fig. 1.
. It is desired to find the thrust against the plane,
, for 1 lin. ft. of the wall. Draw
through
, the foot of the wall, making the angle of repose,