Reply to the discussion by G.H. Lei and J.Y. Shi on "Vacuum and surcharge combined one-dimensional consolidation of clay soils"

Abstract

We appreciate the discussers’ comments and suggestions. Based on their analysis, the discussers have concluded that equal settlements would be expected for soil specimens consolidated under the same vacuum or surcharge pressure. This is in agreement with the experimental results obtained by the authors. The discussers have suggested that a greater volume change may be expected for a soil specimen under a vacuum pressure than under a surcharge pressure of the same magnitude, which they attribute to the all-around contraction of the soil skeleton. However, the authors did not find a significant change in volume in the soil specimen under a vacuum or surcharge pressure of the same magnitude. To fully investigate and understand the difference in the volume change, the discussers have suggested a modification for the vacuum cell to include a sealing membrane for the soil specimen. Although the membrane may improve the measurement for the volume change, it will be very challenging to seal the specimen in the configuration of the vacuum cell described in the study. Having a more sensitive volume change tube in the current configuration may achieve a more accurate volume change measurement. To further understand the vacuum–surcharge consolidation mechanism, the discussers have suggested mounting miniature lateral earth pressure transducers on the inner cell wall and the bottom porous stone to monitor the total pressure changes during the consolidation process. The authors appreciate the suggestion and agree with the potential benefit of such transducers. This modification will be considered in the design of the second version of the vacuum cell. 771