The activation of (self-)weight and loads in a Plastic phase, Consolidation phase and Fully coupled flow-deformation analysis is considered to be an out-of-balance force. In order to solve this out-of-balance, the calculation will use a linear relationship with the ΣMstage multiplier to activate these new loads: once ΣMstage reaches one , the full weight and loads are active in the model. Since in a Plastic analysis, a Consolidation analysis and a Fully coupled flow-deformation analysis the time and the ΣMstage parameter are linearly coupled, this implies that the activation of self-weight and loads is also done linearly in time.
For example when activating a new part of an embankment in a 100 days consolidation phase, the weight of this newly activated volume will then also be linearly mobilized in time: after 25 days, 25% of the self-weight of the newly activated volume is added, and after 50 days, 50% of this self-weight. With this we simulate the consolidation process that occurs due to the gradual construction of an embankment over a period of 100 days. However, if the intention is to build the embankment in just a day, and then let it consolidate for the remaining 99 days, then this should be defined in two phases: