2007 Volume 14 Pages 13-22
SPSP cutoff walls constructed by installing steel pipe sheet piles (SPSPs) at coastal landfill sites are important element of containment facilities preventing the leachate leakage from reclaimed waste to the open sea area. The adhesion with the peripheral ground must be retained in the installation of the SPSPs with joint sections for demonstrating the function which the SPSPs make to be the containment facility. In this study, the generation of turbulence region in peripheral ground around the installation of SPSP cutoff walls is noticed. A seepage and advection/dispersion analysis evaluates the effect of the turbulence region, effect of installation method which suppresses the generation of the turbulence region and soil improvement by the sand compaction pile (SCP) method on environmental preservation function of whole coastal landfill sites with SPSP cutoff walls. As example of result in this study, hydraulic conductivity which turbulence region formed in lower deposition clay layer retained showed that the leakage quantity in the specific route of the toxic substance leakage is greatly affected. The installation method with soil improvement around installing the SPSPs using soil cement was effective in leakage control of the toxic substance.
