論文
八郎潟粘土地盤の圧密変形特性
キーワード:
Hachirogata clay,
differential settlement,
consolidation,
coefficient of secondary consolidation,
theoretical analysis
2020 年 59 巻 1 号 p. 10-17
詳細
2020 年 59 巻 1 号 p. 10-17
In this work, to evaluate the deformation characteristics of Hachirogata clay, soil tests such as one dimensional consolidation test and so on were conducted. Although this Hachirogata clay sample contained much sand and less clay from the grain size test result, it was found that the sample has high liquid limit, plasticity index, and natural water content. About the derived parameters from the consolidation test, the coefficient of volume compressibility, the coefficient of consolidation, and the coefficient of permeability were in the range of 10−4–10−2 m2/kN, 5–100 cm2/d and 10−9–10−7 cm/s, respectively. Compared with other clay samples, Hachirogata clay had low consolidation rate and permeability and high volume compressibility. Furthermore, as a result of analyzing the secondary consolidation behavior in which the strain progresses under a constant load, it was found that Hachirogata clay has high secondary consolidation rate. In addition, assuming the virtual ground composed of Hachirogata clay, the theoretical curve, and the settlement curve considering the secondary consolidation deformation amount were evaluated when the embankment load corresponding to the earth pressure was loaded on this virtual ground. The soil constant required for the calculation was the constant obtained from this consolidation test. It was clarified that it takes a long time to complete primary consolidation, and that the settlement increases when secondary consolidation starts early.
From the above results, it was confirmed that consolidation deformation of Hachirogata clay takes a long time, the amount of deformation increases, and the deformation continues over time after the main deformation is completed.
