Effect of permeability variation in vacuum consolidation

The varying coefficient of permeability plays a major role in increasing the accuracy of the numerical prediction results. This paper aims to evaluate the range of deviation of numerical results if the varying coefficient of permeability is not used during the consolidation time. Four models, one with constant permeability and the others with the varying coefficient of permeability corresponding to different values of Cc/Ck, were used to simulate an axisymmetric single vacuum wellpoint. Comparing those predicted values together and to the measured values, the results show that: the settlement value and the decrease in pore water pressure value of the model which did not consider the change in permeability coefficient were higher than those of the models which considered the change in permeability coefficient during the consolidation process; the bigger the Cc/Ck ratio, the smaller the settlement and the smaller the decrease in pore water pressure. © 2020 Southeast Asian Geotechnical Society. All rights reserved.