A field andtheoretical study of the influence of non-homogeneity on settlement : Conference. Session two Burland, JB Building Res. Station, Watford, GB Sills, GC Building Res. Station, WatforD, GB Gibson, RE Kings College London, GB 6F, 9R Proc. Eighth Int. Conf. on Soil Mech. Found. Engng. Moscow, 1973, V1.3, 1973, P39–46

Abstract

The importance of non-homogeneity on the settlement beneath and around loaded areas is demonstrated in this report which incorporates the results of a full-scale tank loading test and some recent theoretical work. The pattern of observed displacements beneath and around the test tank differed appreciably from that predicted by simple elastic theory. However the solution for an elastic half-space having a linearly increasing stiffness with depth gives remarkably good agreement with the overall pattern of observed displacements. Equally good agreement is achieved using the finite element method of analysis. This variation in stiffness with depth encountered in this investigation is not unusual and it is concluded that the infleunce of non-homogeneity must be taken into account when analyzing such problems as differential settlements and soil-structure interaction. The details of the full-scale tank test are briefly described. Some typical results from the short-term tank tests are illustrated which show the relationships between load-intensity and vertical strain for three levels beneath and outside the tank during loading, unloading and reloading. The plate loading tests were carried out at various depths at the bottom of 900 mm diameter unlined shafts, one of the shafts being alongside the test tank. The finite element analysis was carried out using constant strain triangular elements and the ground was assumed to behave as a linear elastic material having a varying stiffness with depth. The finite element mesh extended to a depth of 180 m where a fixed boundary was imposed. The rigourous analysis performed is also outlined.