Improved calculation method for consolidation of dredger fill treatment using prefabricated vertical-horizontal drains

Prefabricated vertical-horizontal drains (PVHDs) with high efficiency have been applied to accelerate the consolidation of dredger fill foundations. Considering the nonlinear characteristics of soil, the horizontal and vertical drainage paths and the penetration degree of horizontal drainage pipes, an improved consolidation calculation method for dredger fill foundations treated by PVHDs was developed. Sensitivity analysis was carried out on the parameters of the PVHDs system, and the effectiveness of the proposed method was verified by field tests. It is found that the parameters Cc/Ck, loading ratio (Δp/σ'), and penetration degree (ρ) jointly control the rate of the consolidation process. The average settlement consolidation degree (Us) calculated by the proposed method agrees well with the field test values. By increasing ρ from 0.2 to 1.0, the consolidation time can be reduced by half when Us reaches 90%.