, which balances only the thrust of the wedge of rupture, the inclined base of which passes through
.
A conclusive experiment could be made on a high retaining wall, backed by sand or grain (not in a bin, but unconfined except by the wall) after Jamieson’s manner in the case of grain bins, by inserting the rubber diaphragms, etc., at various points from the top down, and measuring the pressures.
In respect to the distribution of pressure, the theory of the sheeted trench differs materially from that of the retaining wall. Much confusion has arisen from confounding them. On that account, and to meet many interesting points made by Mr. Meem, the writer will give a thorough discussion of retaining walls and sheeted or unsheeted trenches, backed by coherent earth.
Fig. 24.
For an unlimited mass of level-topped earth, having both friction and cohesion, but ignoring the cohesion along the vertical plane,
, [Fig. 24], it was shown in the Appendix that the horizontal pressure on a vertical plane,