Original Paper(Vol.61 No.1 pp.46-51)

Vacuum Consolidation for Construction of Expressway Embankment on Extremely Soft Ground

Minoru KAWAIDA, Toshiaki KOSAKA, Koichi YAMADA and Kazuyoshi NAKAKUMA

Abstract:Maizuru-Wakasa expressway was constructed on the soft ground area consisting a thick layer of peat and soft clay. In trial embankment construction, a large lateral displacement and settlement due to embankment load were observed. Therefore, vacuum consolidation (air-water separation system type) was selected to apply to another trial area nearby the previous one to improve the ground for embankment construction. It was found that the vacuum pressure could maintain at high level even after a successive consolidation settlement up to about 10 m, A significantly incremental soil strength after consolidation settlement were observed. The analysis of soil strength increment induced by vacuum consolidation compared to another case history was analyzed and described in this paper

Key Words:Vacuum consolidation, Air-Water separation system, Soil improvement, Humic soil, Strength increase, Settlement acceleration