Large strain consolidation behavior of double-layered vertical drains ground under multi-stage loading

Based on the finite-strain consolidation equation for double-layered vertical drains ground in soft soil and the solution program in some literatures, some examples calculation of consolidation behaviors of double-layered vertical drains ground are carried out under multi-stage loading. The obtained results verifies that:(1) When each stage loading is applied, the void ratio of double-layered soft soil in the radial direction begins to going through the decrease from vertical drains boundary drainage area to away from vertical drains, and the void ratio of the upper layer soft soil decreases faster for its high compressibility. (2) When each stage loading is applied, the average excess pore water pressure of double-layered soft soil in the radial direction increase simultaneously, subsequently, it begins to going through the dissipation process from vertical drains boundary drainage area to away from vertical drains, and the average excess pore water pressure of the upper layer soil dissipates faster for its large permeability; (3) When each stage loading is applied, the average excess pore water pressure of double-layered soft soil in the vertical direction begins to going through the dissipation process from the top soft soil layer drainage area to different depth soil layer, and the average excess pore water pressure of the upper layer soft soil dissipates faster for its large permeability. Average excess pore water pressure at the interface of double-layered soft soil present significant mutation with different consolidation behaviors. © 2015 ejge.