Calcium Leaching Properties of Lime-treated Soil by Infiltration of Tidal River Water

摘要

At present, the leakage is found in foundation of the dike constructed 20 years ago. The dike is constructed along the river in which directly connect to the Ariake Sea surrounded by a vast flat coastal area with very large tidal range. The Ariake clay and lime admixture were used as a main material for the foundation of the dike. The sludge material was found on the surface of lime-treated soil at the leaking point. This condition could weaken the treated soil in the foundation, and subsequently reduce the stability of the dike. In this study, in order to verify the cause of sludge materials leach from lime-treated soil, both water quality analysis in the field and two leaching test (solvent: NaCl and H_2O_2) at the laboratory were performed. There is tendency of Ca~(2+) leach from lime-treated soil due to the high concentration of NaCl and H_2O_2 solvent. The results indicated that the infiltration of tidal river water to the lime-treated soil induces increasing in the leaching of Ca~(2+) in which could reduce the strength of the treated soil.