Leachate control technology using SPSP cutoff walls at coastal landfills

H-H joint of "H-jointed SPSP with H-H joint", which is made up of interlocking two H-steel sections of different sizes, is the one of SPSP's joint to improve the hydraulic conductivity. "H-H jointed SPSP with H-H joint" is expected to be applied to a vertical cutoff wall in coastal landfill sites. In H-jointed SPSP with H-H joint, the H-joint is completely imperviousness. H-H joint, however, is pervious at interlocked state because a gap of 8 to 11 mm is left between the interlocking flanges therefore a water interception treatment must be conducted to seal the gap. The water shielding treatment of H-H joint is executed by coating the gaps with a water-swelling sheet of paint before its installation. Then, hollow space is generated in H-H joint after treating by water-swelling sheet, and that space can be used effectively. This paper proposes leachate control technologies using H-H joint interior space of SPSP cutoff walls. The possibility of those technologies and hydraulic conductivity of H-jointed SPSP with H-H joints are demonstrated by conducting the hydraulic conductivity test.