日本語フィールド
著者：柴 錦春、伊賀屋 豊、日野剛徳 、Carter, J. P. 読み: チャイ ジンチュン、イガヤ ユタカ、ヒノ タケノリ、Carter, J. P.題名：
軟弱地盤上の盛土における有限要素解析ーケーススタディー発表情報：Computers and Geotechnics 巻: 48 ページ: 116-127キーワード：
盛土、数値解析、ケーススタディー概要：抄録：Numerical simulations and field measurements of an embankment constructed on a deposit of soft Ariake clay in Saga, Japan are compared and discussed. The simulations were made both before (Class-A) and after (Class-C) the field data became known. It is shown that the Class-A prediction resulted in poor simulations of the measured settlement-time curves, mainly due to over-estimation of the magnitude of the yield stresses of the sub-soils (i.e., the sizes of the yielding loci) and under-estimation of the compressibility, hydraulic conductivity and the slope (M) of the critical state line in a mean effective stress (p) - deviator stress (q) plot. It is demonstrated that: (a) appropriate site investigation, soil testing and interpretation of the test results are essential for accurate prediction of the behaviour of an earth structure constructed on soft clayey deposits; (b) when using a soil model developed within the framework of Critical State Soil Mechanics to make such predictions, the value of the frictional strength parameter M should be directly determined from tests with an appropriate effective stress path; and (c) yield stresses of soft soil layers can be calibrated by comparing the predicted undrained shear strengths (Su) with measured values, provided the effect of strain rate and/or strain softening on the value of Su is properly considered. The results of this analysis indicate that Bjerrum’s strain rate correction factor can be adopted as a first approximation of the correction factor applied to field or laboratory measured values of Su.英語フィールド
Author：Chai, J.-C., Igaya, Y., Hino, T. and Carter, J. P.Title：Finite element simulation of an embankment on soft clay – case studyAnnouncement information:Computers and Geotechnics Vol: 48 Page: 116-127Keyword：
Embankment, numerical analysis, case studyAn abstract：Numerical simulations and field measurements of an embankment constructed on a deposit of soft Ariake clay in Saga, Japan are compared and discussed. The simulations were made both before (Class-A) and after (Class-C) the field data became known. It is shown that the Class-A prediction resulted in poor simulations of the measured settlement-time curves, mainly due to over-estimation of the magnitude of the yield stresses of the sub-soils (i.e., the sizes of the yielding loci) and under-estimation of the compressibility, hydraulic conductivity and the slope (M) of the critical state line in a mean effective stress (p) - deviator stress (q) plot. It is demonstrated that: (a) appropriate site investigation, soil testing and interpretation of the test results are essential for accurate prediction of the behaviour of an earth structure constructed on soft clayey deposits; (b) when using a soil model developed within the framework of Critical State Soil Mechanics to make such predictions, the value of the frictional strength parameter M should be directly determined from tests with an appropriate effective stress path; and (c) yield stresses of soft soil layers can be calibrated by comparing the predicted undrained shear strengths (Su) with measured values, provided the effect of strain rate and/or strain softening on the value of Su is properly considered. The results of this analysis indicate that Bjerrum’s strain rate correction factor can be adopted as a first approximation of the correction factor applied to field or laboratory measured values of Su.