Stress Increment Solution Charts for Soil Consolidation Analysis
Current practice of estimating average stress increment required for consolidation settlement computations employs mid-depth stress approach or multiple application of sublayer technique, which are tedious and difficult methods to implement for hand calculations. This paper presents simplified charts to estimate such a stress. The influence factor needed to estimate the average stress increment is calculated based on the integration of Boussinesq’s equations for common foundations and various soil configurations. The results are presented in a series of normalized non-dimensional charts, which are independent of structural loads and soil characteristics. The derived charts are useful especially when the compressible layer is not directly located underneath the loaded foundation and they avoid the necessity of dividing the soil into a series of sublayers to obtain a realistic value of average stress increment. They can be readily implemented into design allowing accurate prediction of consolidation settlement or can serve as a powerful tool for optimizing and proportioning the dimensions of footings under certain allowable settlement where otherwise an iterative tedious solution is required. Illustrative examples are presented to demonstrate the applicability and efficiency of the suggested charts for consolidation settlement computations.
