COMPUTATION OF BEARING CAPACITY FACTORS USING FINITE ELEMENTS

The Paper shows how finite elements, in conjunction with elasto-plastic theory, can give excellent collapse load predictions for footings resting on c-φ soils. The problem is approached by considering each of the three components of bearing capacity appearing in Terzaghi's classical equation. The results show that the contributions to bearing capacity of the Nc and Nq terms can be computed with confidence and economy. The NT term, which is theoretically less sound than the other two, is also computed to be in close agreement with published approximate solutions but takes more computing effort. This is shown to be particularly so when the soil friction angle is increased. The superposition assumption in Terzaghi's equation is assessed using finite elements. The conservative nature of the equation is confirmed, with the inherent error shown to occur solely because of non-linearities in the Nγ term. It is thought that the techniques used in obtaining the results given may be applied with confidence to a wide...