In the present study the shape and depth factors of cohesionless soil have been investigated from field tests for graded sand soil. Bearing capacity calculations are an important part of the design of foundations. Many of the terms in the bearing capacity equation, as it is used today in practice, are empirical. Shape factors could not be derived in the past because three-dimensional bearing capacity computations could not be performed with any degree of accuracy. Likewise, depth factors could not be determined because rigorous analysis of foundations embedded in the ground were not possible. In this paper,the bearing capacity of square and circular foundations on sand is determined for frictional soil. The results of the analysis are used to propose values of the shape and depth factors for calculations of the bearing capacity of foundations on sands using the traditional bearing capacity equation. The traditional bearing capacity equation is based on the assumptions that effects of shape and depth can be considered separately for soil self-weight and surcharge (embedment) terms. This assumptions is not realistic, so a different from of the bearing capacity equation is alsso proposed that does not rely on it. The shape and depth factors have been determined from experimental test results. Also, empirical formulii to determine the shape and depth factors as well as bearing capacity of cohesionless soil are presented. |
