MODELING OF SETTLEMENT AND BEARING CAPACITY OF SHALLOW FOUNDATIONS IN OVERCONSOLIDATED CLAYS

This paper focuses on the characterization of the fine-grained soils of Pucallpa and on theoretical and numerical analyses of their bearing capacity. A review of data related with field investigation and laboratory testing is first presented aiming the assessment of geotechnical parameters for modelling the mechanical behavior of overconsolidated clays with a numerical model based on both frictional and critical state models. Considering the finite element method, several models under plane strain conditions are built for the evaluation of the ultimate bearing capacity of the soil foundation. In each model, the initial stresses used to start the simulations are obtained according to different overconsolidation ratios. Then, the ultimate bearing capacities obtained are compared with some theoretical solutions based on drained and undrained shear strengths. According to the results, the theoretical solution that considers a general shear failure mode can provide a good forecast of the ultimate bearing capacity of overconsolidated clays under drained conditions. However, depending on the allowable settlements, the bearing capacity can be significantly lowered to avoid damage to structures and buildings, even for highly overconsolidated clays.