Samenvatting

This thesis aimed to understand how Tensar’s current design methods work, in relation to the calculation of working platforms. Thereafter, a full breakdown of each design method’s limitations was addressed, with this thesis focusing on the problem of stratification, in the T-value method. This limitation means that multiple layers cannot be taken into account within a given influence depth. Therefore, when a stronger soil lies beneath a weaker one, there is a potential of an added benefit to be won. On the other hand, when a weaker soil lies beneath a stronger one, real risks of over predictions in bearing capacity exist. Although, this is up to the designer to take into account and adjust accordingly. One such stratified soil, had a fully monitored trial test conducted, referred to as the Wieringermeer trials. However, these trials were never able to fully achieve failure. Therefore, this thesis aimed to accurately estimate the bearing capacity of the trial, using the finite element analysis software, PLAXIS 2D. Thereafter, these validated results and the most important stratification parameters, were used to derive a host of improvement variants. However, as a single set of data would not be enough to make any reliable conclusions, a further 11 stratified soils were created from the original. The combination of both an influence depth and a parameter summarisation variant, served to reliably predict the effect of stratification on the bearing capacity, compared to the existing design method. A validated choice based on existing literature and insight gained from modelling was shown to reliably predict bearing capacities of stratified soils, as well as performing better than the existing methods. Thereby, adding to a quantifiable benefit to safety, the environment and monetary gains for Tensar’s working platform design methods.