Prediction of foundations behavior by a stress level based hyperbolic soil model and the ZEL method

In shallow foundations, the third bearing capacity factor, N, has been found to show a decreasing tendency with increasing the foundation size. It is supported by experimental observations and related mainly to stress level dependent nature of the soil. On the other hand, the bearing capacity is often obtained theoretically without consideration of the foundation vertical displacements. In this study, a simple form of the stress level dependent hyperbolic soil model is presented and implemented in the Zero Extension Lines (ZEL) method to predict the bearing capacity and load-displacement behavior of shallow foundations. A computer code is developed for this study. A procedure to find the actual behavior of relatively large foundations based on laboratory and in situ small scale or plate load tests data is also presented. An existing experimental full scale load test is investigated and analyzed with the presented method to show the possibilities and advantages of the method in comparison with ordinary approaches. The results show that the presented method is applicable for practical problems to provide a more precise estimate of the bearing capacity of shallow foundations.