Abstract: In this paper, the problem of viscoelastic consolidation of soft clay ground with vertical drain wells considering semi-permeable boundaries that may result from the defective drainage capacity of both sandcushion and substratum in practical engineering is studied, and the analytical solutions are obtained. Based on these solutions and relevant computations, the influences of semi-permeable boundaries and viscoelastic parameters of soil on the consolidation process are investigated and discussed. It shows that the semi-permeable boundaries affect the consolidation process significantly and the effect is related to many factors such as well resistance. However, if the values of parameters Rv1 and Rv2 which represent the drainage capacity of sand cushion and substratum are large enough, the semipermeable boundaries can be taken as pervious completely.

Key words: vertical drain well , viscoelasticity , consolidation , semipermeable boundary , sand cushion , substratum