Abstract: Based on some simplification and assumption of one-dimensional finite-strain consolidation theory and Barron axisymmetric consolidation theory, a finite-strain consolidation governing equation for vertical drains ground is established. Based on the finite-strain consolidation equation for double-layered vertical drains in soft soil and the computing program in some literatures, the power function relationships of permeability coefficient-void ratio k=ced and effective stress-void ratio e=a( )b for soft soil are introduced; and some examples calculation of consolidation behaviors of double-layered vertical drains ground are carried out under instantaneous loading. The obtained results show that: (1) Some important influence on the consolidation behaviors of double-layered vertical drains ground of various parameters in power function permeability and compressibility relationships for double-layered soft clay soil are as follows. With the increase of parameters c1, c2 of power function permeability relationship (the increase of permeability), or parameters a1, a2 of power function compressibility relationship for soft soil, the void ratios in the radial and vertical directions decrease faster; and the dissipation velocity of excess pore water pressure and the settlement rate are also accelerated; the settlement development rate is faster than the dissipation velocity of excess pore water pressure. (2) The void ratio and average excess pore water pressure at the interface of double-layered soft soil present significant mutation, of which the distribution curve along the depth is divided into two sections with different consolidation behaviors.

Key words: soil mechanics, finite-strain consolidation, double-layered vertical drains ground, soft soil, power function permeability relationship, power function compressibility relationship