Abstract: Aiming at the optimal installation of horizontal drainage channels in hydraulic fill reclamation projects, one dimensional consolidation model with drainage channels installed in the foundation which considering the non-uniform distribution of initial excess pore water pressure was established. The analytical solution was obtained using the finite sine Fourier transform method. After verifying the correctness of the solution, the optimal position of the drainage channels under different time factors was solved and also given in the diagram form. The results show that drainage channels should be installed at the depth of soil layer with great excess pore pressure at the early stage of consolidation, and turn to 2H/3 (PTIB) or H/2 of soil (PTPB) at the later stage of consolidation (H is the depth of foundation). In order to save the consolidation time when the degree of consolidation reaches 90%, the optimal installation depth of horizontal drainage channels was 0.52H, 0.72H, and 0.62H for the single-drainage condition with the distribution of initial excess pore pressure in the inverted triangle, triangle and trapezoidal pattern, respectively. For the double-drainage condition, the optimal installation depth of horizontal drainage channels was 0.42H, 0.58H, and 0.46H, respectively. A practical example shows that the foundation with optimal depth of horizontal drainage channels has higher consolidation degree (6% and 54%) than that with drainage channels installed in 0.5H and without drainage channels installed.

Key words: one-dimensional consolidation, analytical solution, optimal installation of horizontal drainage channels, non-uniform distribution of initial excess pore water pressure