Two-Dimensional Analysis of Stress and Strain in Soils, Report No. 2. Development of Plastic Zone Beneath a Footing

摘要

An earlier report by Whitman (AD-608 874) analyzed the need for more adequate computational procedures than presently in use for problems in soil engineering. Whitman studied the potential usefulness of plasticity theory for this purpose and suggested the application of a lumped parameter model developed by Ang and Harper (1964) to calculate the distribution of stresses and strains within soil masses. This report presents a continuation of Whitman's studies and had as its main objectives: (1) to examine the performance and accuracy of the computational model; and (2) then proceed to analyze the development of the plastic zone beneath a strip footing resting on an elastic-perfectly plastic foundation material. The report concludes that the use of the simple discrete model is a promising approach, and similar techniques will be applied during a continuation of this research program. The computed results for the flexible and rigid strip footings analyzed in this study, showed the gradual development of the plastic zone, the corresponding displacement fields, and the accumulation of footing settlements as the full shearing resistance of the foundation material was mobilized. The load-settlement curves approached asymptotically the bearing capacity which was in agreement with the ultimate load predicted by plasticity theory. (Author)