Analyzing the Deformation of Multilayered Saturated Sandy Soils under Large Building Foundation

摘要

The generalized plasticity theory has been subject of much research in geomechanics. The Pastor-Zienkiewicz model and its modified versions are among these. For large foundations resting on multilayered soils the actual loading is often non-linear. In this study we developed a new mathematical model which can apply non-linear loading using the subfield of planar mesh method. A sensitivity study was first performed to evaluate the contribution of deformation from various model parameters. It is found that the plastic modulus parameters only have marginal contributions. An engineering case study was used to valid the proposed model and it is evident from measured stresses that the loading of the foundation is non-linear. The deformations calculated by the proposed model agreed well with the monitored deformations. It is also found that the maximum deformation point is not necessarily in the centre of foundation and it does not coincide with the maximum loading point either. The distance between the maximum deformation point and the maximum loading point can be as far as 15.59 m for the bottom layer soil from this case. This research proves the necessity of using non-linear loading to calculate the foundation deformations for large foundations with multilayered saturated soils.