SETTLEMENT OF SHALLOW FOUNDATIONS ON GRANULAR SOILS

A conceptual framework for understanding the effects of overconsolidation in reducing the compressibility of all types of soils is presented. A generally applicable method for estimating the settlement of footings on granular soils is presented. The procedure uses a combination of dilatometer and cone-penetration test results to identify the preconsolidation pressure, while soil moduli—either Young’s modulus or constrained modulus, depending on the boundary conditions—are obtained from the dilatometer test results. Calibration chamber test results are used to adjust the dilatometer moduli for the effects of stress path and for disturbance due to insertion of the instrument. Detailed examples are given to illustrate the use of the method and to compare the results obtained with those calculated using currently accepted methods for estimating settlements.