Comparative probabilistic analysis of bearing capacity formulae for shallow foundations using Monte-Carlo simulation

摘要

In order to calculate the bearing capacity of shallow foundations different formulae are used, most of which are based on Terzaghi's formulation. This formula has been used for a long period and is still broadly in use, but during years several changes are made to take into account vanous factors The bearing capacity that results from the application of these formulae (q_(ut)) is divided by a safety factor (mostly based on previous experience) and the obtained allowable bearing capacity (q_(all)) is used to define the foundation dimensions In order to consider the uncertainties of the soil properties (φ, c and γ) is necessary to make a probabilistic analysis of the bearing capacity. Using this analysis is possible to give a more accurate judgment about the use of the safety factor for different reliability levels In this paper, a comparison between the deterministic and probabilistic calculations of the bearing capacity, using Monte Carlo simulation, is done. This comparison is done in the context of a formula used broadly in Albania, which is used to calculate the soil bearing capacity R. This formula differs from Terzaghi's formula in some aspects and has an incorporated safety factor.