An Introduction to Stress Conditions in Soil for Professional Engineers

This discussion describes the analysis of stress conditions within the ground, including stress at a point, changes in stress caused by the application of soil and structural loads, and empirical methods for estimating loads on buried pipes, conduits, shafts, and tunnels. The calculation of stresses and changes in stress using numerical methods, such as the finite element method, is also discussed. The state of stress within the ground can be analyzed assuming that either elastic or plastic conditions prevail. Elastic solutions are most appropriate for cases in which the shear stresses throughout the soil mass are significantly below the shear strength of the soil and shear failure is not likely. If the shear stress in the soil is less than about one-third of the ultimate shear strength, the stresses within the soil mass will be roughly equal to values calculated from elastic theory. The stress conditions calculated using most of the methods in this chapter assume that elastic conditions prevail. Plastic solutions assume full mobilization of the soil's shear strength within a soil mass or along a specified failure surface. Plastic equilibrium is used for problems, such as slope stability. foundation bearing capacity, and lateral earth pressures, where shear strength may be fully mobilized.

Pages: 75, Paperback, Independently published