A two-dimensional effective stress framework for modelling whole-life soil strength changes due to pore pressure generation and dissipation, Part 2: Applications

Abstract

Accurate quantification of the temporal changes in seabed strength allows for more reliable and less conservative geotechnical design. A recently developed effective stress framework, established within a one-dimensional computational domain to quantify changes in soil strength due to pore pressure generation and dissipation, has been extended to a two-dimensional (2D) computational domain to allow for consideration of boundary value problems that are too complex to be simplified to one-dimensional conditions. The work to implement the 2D framework is reported across two companion papers. The first of the two papers utilises large deformation finite element analyses to quantify the spatial distribution of accumulated plastic shear strain. These distributions are encapsulated within a strain influence function that is used within the new 2D framework in this paper to calculate the extent and magnitude of excess pore pressure, and in turn the mobilised soil strength for a number of boundary value problems that represent typical offshore geotechnical processes. The merit of the new 2D framework is explored via retrospective simulations of existing experimental and numerical data. The resulting comparisons demonstrate the potential of the new framework, which is in quantifying the reliability of a range of geotechnical structures under complex loading conditions.