Simulation and evaluation of improvement effects by vertical drains/vacuum consolidation on peat ground under embankment loading based on a macro-element method with water absorption and discharge functions

The next objective of this study is to investigate the impact of ground improvement, using vertical drains and vacuum consolidation with embankment loading on a soft ground, placing a particular focus on the effect of drain spacing. In this case, an ultra-soft ground with alternating peat and clay layers was modeled to represent a typical ground to which vacuum consolidation would be applied. Based on a series of simulations, it was found that, although the use of vacuum consolidation in combination with vertical drains is effective in cases where it is necessary to limit the deformation of the surrounding ground, the same reduction in residual settlement can be achieved using vertical drains alone, provided that the drains are deployed at a sufficient frequency.