Evaluation and improvement technology of environmental feasibility for cutoff walls using steel pipe sheet piles in coastal landfill sites

Abstract

In the coastal landfill sites, the evaluation methods, construction technologies and long-term maintenance which ensure environmental feasibility of cutoff wall using steel pipe sheet piles with the jointed sections (SPSPs cutoff wall) are complicated both experimentally and analytically. In this study, the effect of SPSPs cutoff walls in coastal landfill site on the containment of toxic substance was evaluated by seepage and advection/dispersion analysis, and the relevance was examined with respect to performance and installation condition of SPSPs cutoff walls and environmental feasibility. In addition, the improvement of environmental feasibility and construction technology for SPSPs cutoff walls was proposed by the application of the H j ointed SPSPs with H-H joints which is one of the originally developed SPSPs. Furthermore, the long-term maintenance of water interception performance of H-jointed SPSPs with H-H joints cutoff walls demonstrate was proposed with the management repair technique. From a series of result, the hydraulic conductivity of SPSPs cutoff walls required for environmental preservation of coastal landfill sites of 1×10-8 cm/s order is clarified from infiltration and advection variance analysis. In addition, it is also clarified experimentally that H j ointed SPSPs with H-H joints can demonstrate the hydraulic conductivity of the 1×10-8cm/s order. The features in maintenance and management repair of the H-jointed SPSPs with H-H joints for the conventional steel pipe sheet pile are shown.