Now showing 1 - 3 of 3
  • Publication
    Use of a genetic algorithm to perform reliability analysis of unsaturated soil slopes
    (Institution of Civil Engineers, 2009-08) ;
    Rainfall induced landslides are a major cause of disturbance to transport networks in many parts of the world. In slopes where the water table is some depth below the ground surface, negative pore water pressure (suctions) develop in the near surface soils which contribute significantly to their overall stability. However, these suctions are transient and reduce as water percolates into the slope (and a wetting front develops) during periods of heavy or prolonged rainfall. In this paper the development of a model for determining the reliability of a slope in which the soil properties are considered as random variables is presented. By transforming the variables into polar coordinates the complexities associated with defining the limit state function, which have affected many previous attempts at probabilistic analysis of slopes, can be overcome. The minimisation problem is solved in a powerful and efficient Genetic Algorithm environment.
      1924Scopus© Citations 30
  • Publication
    Effect of rainfall intensity on infiltration into partly saturated slopes
    (Springer, 2008-04) ;
    This paper describes the development of a model to analyse the rate of infiltration and run-off experienced by a partly saturated soil slope during rainfall. The paper first reviews some of the most popular infiltration models used in geotechnical analysis, and highlights some of the problems associated with their application. One particular model, the Horton Equation is extended to include rainfall intensity directly in its formulation. The new model is shown to predict infiltration responses, which agree with field measurements. In the final section the influence of the rainfall intensity and pattern of rainfall (variation of rainfall intensity) on the infiltration response of a soil is investigated using the new model.
      10222Scopus© Citations 49
  • Publication
    Design charts for the stability analysis of unsaturated soil slopes
    (Springer, 2010-01) ;
    Simple limit equilibrium analyses can be performed to determine the Factor of Safety (FOS) against slope failure of unsaturated soil slopes. However, many of the input parameters needed for these analyses are highly variable, and the FOS value obtained is critically dependent on assumptions made by the designer. This paper describes a suite of reliability analyses on unsaturated soil slopes performed using an invariant reliability model. The results are presented in design charts from which a designer can choose the FOS value required to ensure a given target reliability index for a slope. The approach ensures that despite the variability of input parameters the slope will have a probability of failure of 2.23% or less.
      2396Scopus© Citations 16