O38 Email from Nov 13 2025 to Dec 9 2025 between Mr Kleinberg and Mr Seele

tion and a given seepa condition, the shear stress required for equilibrium c: be determined with great accuracy. Uncertainty as tot stability hence arises from uncertainty as to the shc strength, The safety factor F for an infinite slope thus ¢ presses the amount by which the shear strength can be error and still have equilibrium. When an infinite slope nature fails, it usually means that the shear strength the soil has decreased through weathering and ot! geological processes. Such a failure may take the fo: of a gradual downhill creep or may involve a vc sudden and extensive slip. Actually, the depth tot phreatic surface will generally vary somewhat throughe the year, and so too will the shear stress required | equilibrium. The worst condition usually occurs duri severe rains, and most failures also occur during su periods. In evaluating F for an infinite slope, the wo condition—the phreatic line at the surface of the slope- generally assumed. 24.3. GENERAL BEHAVIOR OF SLOPES OF LIMITED HEIGHT ‘ In many problems ¢ is large enough so that the criti: depth becomes quite large: 25 ft, 100 ft, or even mv more. When H, approaches the height of the slope, 1 problem must be treated as a slope of limited height. The first signs of imminent failure of a slope i usually an outward or upward bulging near the toe a the development of cracks near the crest of the slo Failure involves a downward and outward motion soil until a new position of equilibrium is achiev During this movement the sliding mass often breaks into smaller blocks. Often the surface of sliding is m: or less circular, as in Fig. 24.84. In some problems location of the failure surface and the shape of sliding mass are influenced by weak strata within soil, as indicated in Figs. 24.86 and 24.8c, -