This book presents simplified and advanced probabilistic analyses of shallow foundations. In the simplified probabilistic analysis the uncertain parameters are modelled by random variables defined by their probability density functions. In other words, the soil is considered homogeneous. However, in the advanced probabilistic analysis, the uncertain parameters are modelled by random fields characterized not only by their probability density functions, but also by their autocorrelation functions. This allows studying the effect of the soil spatial variability on the behaviour of shallow foundations.