記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.91.I_239

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担当区分：筆頭著者   掲載種別：研究論文（国際会議プロシーディングス）  

DOI： 10.1061/9780784484999

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1080/17499518.2023.2164901

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

DOI： 10.1002/nag.3435

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その他リンク： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/nag.3435

記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.7831/ras.10.0_138

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscejge.78.2_140

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.sandf.2020.09.004

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.4417/IJGCH-06-04-06

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担当区分：責任著者   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.89.I_181

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）  

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.sandf.2020.01.009

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.88.I_105

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.sandf.2019.08.002

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）  

DOI： 10.11408/jsidre.87.II_29

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担当区分：責任著者   掲載種別：研究論文（学術雑誌）   出版者・発行元：Springer Science and Business Media LLC  

DOI： 10.1007/s10333-019-00722-5

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その他リンク： http://link.springer.com/article/10.1007/s10333-019-00722-5/fulltext.html

掲載種別：研究論文（学術雑誌）   出版者・発行元：Elsevier BV  

DOI： 10.1016/j.sandf.2018.09.006

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscejam.75.1

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscejge.74.213

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掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscejam.74.i_95

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記述言語：日本語   掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：AMER SOC CIVIL ENGINEERS  

The spatial distribution of the strength inside river dikes is generally identified through sounding tests. In this research, the electric Cone Penetration Test (CPT) is employed, and spatially long- and short-interval tests are mixed to efficiently evaluate the piping risk to a dike. The Indicator Simulation (IS) method is used as the geostatistical method to simulate the N value distribution and to predict the weak area inside the dike. The synthesized approach of the CPT and the Surface Wave Method (SWM), which is one of the geophysical methods, is proposed to compensate for the shortcoming of each approach when conducting the IS. Consequently, the correlation structure inside the dike can be identified accurately, the high resolution of the spatial distribution of the N values can be visualized, and the piping risk to the dike can be discussed based on the results of the investigation.

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記述言語：日本語   出版者・発行元：地盤工学会  

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Taylor and Francis Ltd.  

The spatial distribution of the strength inside the earth-fill is identified by the sounding tests. In this research, the Swedish weight sounding (SWS) is employed, and the spatial high-density test is performed to identify the spatial correlation structure. Furthermore, the synthesised approach of the SWS and surface wave method, which is one of the geophysical method, is proposed to compensate the shortage of each approach. Consequently, the correlation structure of an earth-fill could be identified accurately, and the high resolution of the spatial distribution could be visualised based on the survey results.

DOI： 10.1080/17499518.2016.1197406

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その他リンク： http://www.tandfonline.com/doi/pdf/10.1080/17499518.2016.1197406

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Taylor and Francis Ltd.  

ABSTRACT: This paper deals with a strategy for the maintenance of geotechnical structures such as earth-fill dams. Standard penetration test (SPT) N-values are frequently used to determine the soil parameters. For this purpose, a statistical model for the N-values is firstly determined from sounding test results. In this research, however, Swedish weight sounding (SWS) tests are employed as they are simpler than SPTs. The identification of spatial correlation of the soil parameters is very difficult, since the number of sampling points is very limited to model the spatial variability. SWS is advantageous, compared with other major sounding method to identify the spatial correlation structure inside the geotechnical structures, since it makes spatially short-interval exams possible due to its simplicity and compactness. Based on the statistical model for the N-values, the shear strength parameters are derived through the empirical relationships. Then, a reliability analysis of the embankments is conducted considering the variability of the internal friction angle and the seismic hazard. Consequently, the probability of damage to the earth-fill over the next 50 years is calculated, and the effect of improving the earth-fill is evaluated based on this probability.

DOI： 10.1080/17499518.2015.1124123

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：公益社団法人 農業農村工学会  

Recently, the evaluation of the failure potential of earth-filled dams has become important because of the increasing occurrence of storm rainfall. Although most instances of earth-filled dam failure are caused by overflow, in-depth knowledge of the mechanism of the erosion and failure process of embankments due to overflow is still lacking. This paper presents a numerical method for simulating an embankment erosion and failure process by the moving particle semi-implicit (MPS) method. To reasonably simulate the erosion and failure process of an embankment due to overflow, a simple erosion model whose parameters can be determined through erosion tests on embankment materials was newly incorporated into the original MPS method. An embankment erosion and failure process observed in a model test was simulated by the proposed MPS method to confirm its practicability. Although the simulation accuracy for the erosion rate is slightly low at the beginning of the erosion, the average simulated values of the erosion rate are almost the same as the experimental values. The proposed MPS method can be a useful tool in embankment design practices to simulate embankment erosion due to overflow and to discuss remedial measures against overflow.

DOI： 10.11408/jsidre.84.I_31

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その他リンク： https://jlc.jst.go.jp/DN/JLC/20020753557?from=CiNii

掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscejam.72.i_97

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記述言語：日本語   出版者・発行元：公益社団法人 農業農村工学会  

ため池の破堤は下流域に大きな洪水を発生させ, 農業水利施設の中で最も甚大な被害を生じさせる事象の一つである．したがって, ため池破堤時の被害額を適切に推定することは, 土地改良事業のリスク評価やリスク管理に取り組む上で非常に重要な課題となっている．ため池破堤リスクの評価には, 氾濫解析を行った上で氾濫域の資産データを収集整理し被害額を推定する手法が一般的に用いられている．しかしながら, この手法は複雑であり, 作業に多くの時間や労力が必要となるため, 計画段階で実施する概略検討に適用することは困難である．このような背景から筆者らは, 複雑な解析を簡易な代替モデルで置き換える応答曲面法に着目し, ため池破堤による被害額を算定する応答曲面（Response Surface）を先に提案した．本研究では, 筆者らが提案した応答曲面を集中豪雨時におけるため池破堤のリスク評価に適用し, その実用性について検証することを目的とする．実在する4つのため池地区の応答曲面による被害額と既定の手法による被害額との差の値は, 応答曲面を作成した21ケースの不偏分散よりも小さい結果となり, 提案した手法は集中豪雨によるため池破堤リスクの簡易評価への活用が期待される結果が得られた．

DOI： 10.11408/jsidre.84.I_47

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その他リンク： https://jlc.jst.go.jp/DN/JLC/20020753571?from=CiNii

記述言語：日本語   出版者・発行元：農業農村工学会  

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掲載種別：研究論文（学術雑誌）  

DOI： 10.2208/jscejam.72.i_35

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Asian Regional Conference on Soil Mechanics and Geotechnical Engineering  

This study has investigated sensitivities of input parameters in stability analysis of embankments to safety factor Fs based on experimental deign. In addition to the geotechnical parameters, parameters about geometry such as height, width, and slope gradient of embankments were also considered in the analysis. This study applied regression analysis based on orthogonal design to the sensitivity analysis. The geotechnical parameters required for the stability analysis were used in the sensitivity analysis, and the sensitivity of these parameters to Fs was investigated. The results of the sensitivity analysis showed that the parameters about geometry of embankments such as height and slope gradient are more sensitive to Fs, although the parameters about hydraulic characteristics of embankment material are less sensitive to the Fs.

DOI： 10.3208/jgssp.JPN-034

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掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：CRC PRESS-TAYLOR & FRANCIS GROUP  

This study has investigated sensitivity of input parameters in stability analysis of earthen embankments to its factor of safety (F-s) using an experimental design approach. Computer experiments based on orthogonal designs were carried out to achieve efficient experiments, and a linear regression model was applied to analyze the results of the experiment. The Standardized Regression Coefficients (SRCs) obtained from the regression analysis was employed as indexes of the sensitivity of the input parameters to the F-s. The results of the sensitivity analysis showed that the parameters about the geometry of embankments such as height and slope gradient are more sensitive to F-s, although the parameters about hydraulic characteristics of embankment materials are less sensitive to the F-s. In addition, interaction effects between input parameters were also analyzed, and its sensitivity to F-s was discussed.

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記述言語：日本語   出版者・発行元：公益社団法人 農業農村工学会  

地震や集中豪雨による農業用ため池の決壊は，下流域に大きな洪水を発生させ，農業水利施設の中で最も甚大な被害を生じさせる事象の一つである．このため，土地改良施設のリスクを評価しその機能を保全しようとする際に，ため池が決壊した場合の被害額を事前に想定することは非常に重要となる．一方，国が定める被害額算定手法は複雑であり，様々な資産データの収集・整理に多大な労力や時間を必要とする．そこで本研究では，ため池が決壊した場合の氾濫域における被害額を算定する簡易な手法を提案する．提案する手法は，対策を講ずる地区の選定時等に実際に適用できるよう容易に入手可能な資産データのみを用いることとした．3池の氾濫解析結果に提案する手法を適用し被害額を算定した．その結果，規定の方法と大差無く被害額を算定できたことから，提案する手法は有用との結論が得られた．

DOI： 10.11408/jsidre.83.39

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その他リンク： https://jlc.jst.go.jp/DN/JLC/20021009394?from=CiNii

記述言語：日本語   出版者・発行元：地盤工学会  

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10422689

記述言語：日本語   出版者・発行元：The Japanese Society of Irrigation, Drainage and Rural Engineering  

我が国には江戸期以前に築造されたものも含め農業用ため池が数多く存在し, 地震や豪雨のリスクに常に直面している．このため, 遅滞なく効率的に改修等のハード対策や管理体制の強化等のソフト対策を講ずる必要があり, 破堤時の想定被害額を考慮しながら優先順位を決定し計画的に対応を図ることが求められている．しかしながら, 既定の氾濫解析に基づく被害額算定手法は複雑であり, 優先度を検討する数多くのため池の被害額を一度に算定することは難しいことから, 容易に被害額を推定できる簡略化された手法が必要となる．本研究では, このような課題に対応するため, 応答曲面法を用いて被害額を簡易に推定する手法を提案する．応答曲面法とは, 実験計画法に基づく回帰分析により, 因子と応答との定量的な関係を表現する回帰式を作成する手法であり, 得られた回帰式は応答曲面と呼ばれる．被害額算定に考慮すべき多くの因子について感度解析を行い, 被害額の値に大きく寄与する4つの因子を抽出した．これらの因子を用いて作成した応答曲面の決定係数R²は0.84と高く, 行政機関等が行う被害額の簡易推定への実用の可能性が示唆される結果が得られた．

DOI： 10.11408/jsidre.83.I_147

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その他リンク： https://jlc.jst.go.jp/DN/JLC/20015919326?from=CiNii

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：CRC PRESS-TAYLOR & FRANCIS GROUP  

This research deals with a strategy for the maintenance of geotechnical structures such as earth-fill dams. Standard PenetrationTest (SPT) N-values are frequently used to determine the soil parameters. Firstly, a statistical model for the N-values is determined from sounding test results. In this research, however, Swedish Weight Sounding (SWS) tests are employed as they are simpler than SPT. Secondly, an indicator simulation is conducted to interpolate the spatial distribution of the N-values, and the results are utilized to find degraded areas inside the embankments and to maintain the embankments. Based on the statistical model for the N-values, the shear strength parameters are derived through the empirical relationships. Then, a reliability analysis of the embankments is conducted considering the variability of the internal friction angle and the seismic hazard.

Web of Science

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：CRC PRESS-TAYLOR & FRANCIS GROUP  

This study presents an eco-friendly design method for infrastructures based on contingent valuation method (CVM). First, a questionnaire survey based on the CVM was conducted to estimate monetary values of stream habitat which can be damaged by river improvement works such as flood prevention works. Second, a design method which can quantitatively evaluate impacts on stream habitat due to flood prevention works was proposed by combining computation of non-uniform flow with a method of stream habitat estimation called physical habitat simulation model (PHABSIM). Finally, monetary value of environmental loss due to flood prevention works was estimated by using results of CVM, and the effectiveness of the eco-friendly design method was discussed through a numerical example.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IOS PRESS  

Strong nonlinear behavior such as slope failure involves large uncertainties. Even if we conduct model tests on slope failure under the same test conditions, we cannot reproduce the same results although the linear behavior can be reproduced with relative ease. This kind of uncertainties is well known as "aleatory uncertainty" and they should be distinguished clearly from the epistemic uncertainty in reliability-based design. However, characteristics of aleatory uncertainty have not been studied very well so far. This study quantitatively investigates the aleatory uncertainties involved in failure behavior of slopes thorough centrifuge model tests. The centrifuge model tests were conducted under the same test conditions twenty times to quantitatively investigate the variability of slip lines.

DOI： 10.3233/978-1-61499-580-7-353

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IOS PRESS  

The spatial distribution of the strength inside an earth-fill dam is identified by sounding tests. In this research, the Swedish Weight Sounding (SWS) test is employed, and the spatially high-density test is possible to identify the spatial correlation structure by the SWS. The correlation structure of an earth-fill could be identified accurately based on the sounding results, and the high resolution of the spatial distribution could be visualized by using the indicator simulation. Consequently, it has been verified the practical use of the spatial distribution of the probability that the N-value is lower than the threshold value, may be used for the maintenance of an earth-fill dam.

DOI： 10.3233/978-1-61499-580-7-334

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：CRC PRESS-TAYLOR & FRANCIS GROUP  

This research deals with a strategy for the maintenance of geotechnical structures such as earth fill dams. Standard penetration test (SPT) N-values are frequently used to determine the soil parameters. Firstly, based on the statistical model for the N-values, the shear strength parameters are derived through the empirical relationships. Secondly, a reliability analysis of the embankments is conducted considering the variability of the internal friction angle and the seismic hazard. Thirdly, the probability of overflow of earth fills during heavy rains is evaluated. The rainfall intensity is dealt with as a probabilistic parameter, and the various rainfall patterns are tested by the Monte Carlo method.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：American Society of Civil Engineers (ASCE)  

This research deals with a strategy for the maintenance of geotechnical structures such as earth-fill dams. Standard penetration test (SPT) N-values are frequently used to determine the soil parameters. Firstly, a statistical model for the N-values is determined from sounding test results. In this research, however, Swedish weight sounding (SWS) tests are employed as they are simpler than SPT. Secondly, an indicator simulation is conducted to interpolate the spatial distribution of the N-values, and the results are utilized to find degraded areas inside the embankments and to maintain the embankments. Based on the statistical model for the N-values, the shear strength parameters are derived through the empirical relationships. Then, a reliability analysis of the embankments is conducted considering the variability of the internal friction angle and the seismic hazard.

DOI： 10.1061/9780784413609.236

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記述言語：日本語   出版者・発行元：The Japanese Society of Irrigation, Drainage and Rural Engineering  

兵庫県南部地震による被害ため池40個，無被害ため池45個の堤体土から，多変量解析結果を基に，震央距離，堤体量（堤高×堤長），断層距離がほぼ同じ組合せを選び土質特性を比較した．被害ため池堤体土の測定値（平均）は無被害堤体土に比べ，土粒子密度は2.66g/cm³で同じだが，50％粒径は0.514mmで4.5割，含水比は9.4％で約3割，貫入抵抗は223kPaで3割以上小さい．被害率は，含水比および貫入抵抗が低いほど大きくなり，含水比6％未満の堤体は18％以上の堤体の3倍，貫入抵抗が200kPa以下の堤体は400kPa以上の堤体の2.6倍であった．三角座標法土質分類では，被害・無被害の差別化が不十分であった．新たに提案した砂分・細粒分のみに基づくFS分類法により，砂質系土の被害率は，礫質系土の2倍以上となった．比較的簡単な指標により被害・無被害堤体の土質特性が定量化でき差別化できた．

DOI： 10.11408/jsidre.82.1

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その他リンク： https://jlc.jst.go.jp/DN/JLC/20005785436?from=CiNii

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記述言語：日本語   出版者・発行元：農業土木学会  

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掲載種別：研究論文（学術雑誌）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：American Society of Civil Engineers (ASCE)  

This study presents a reliability-based design method for geotechnical structures based on the observational method, which can be used as a methodology for the performance verification of geotechnical structures. In the proposed method, the soil-water coupled finite element analysis is utilized as a performance-verification method, and stochastic uncertainties inherent in the geotechnical parameters are evaluated by a Monte Carlo simulation. The proposed method can select the optimum design/construction method from several design alternatives, from the viewpoint of Life Cycle Cost, and the predictions at the initial design stage are sequentially updated by the particle filter. The proposed method is applied to a numerical example of the construction problem of embankment specified quantitative performance criteria, such as allowable settlements and the probability of their exceedance, and the feasibility of the method is examined in this example.

DOI： 10.1061/9780784413609.246

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：International Society of Offshore and Polar Engineers  

This study describes a numerical simulation method for dyke breach process due to overflow based on Moving Particle Semi-implicit (MPS) method. The MPS method was developed for incompressible flow with free surface. In the MPS, fluids and geomaterials to be analyzed are represented by particles, and the governing equations describing the mechanical behavior are discretized by particle interaction models. Since MPS method does not need grids, it can be applied to large deformation behavior such as dyke breach process. The MPS method was extended by adding a simple erosion model for simulating breach process of dyke due to overflow. The simulation results for breach process of the dyke by the MPS method were compared with the corresponding observation data to verify the applicability of the MPS method presented in this study. Copyright © 2014 by the International Society of Offshore and Polar Engineers (ISOPE).

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：International Society of Offshore and Polar Engineers  

This study presents an eco-friendly design method for infrastructures based on contingent valuation method (CVM). First, a questionnaire survey based on the CVM was conducted to estimate monetary values of stream habitat which can be damaged by river improvement works such as flood prevention works. Second, a design method which can quantitatively evaluate impacts on stream habitat due to flood prevention works was newly proposed by combining non-uniform flow analysis with a method of stream habitat estimation. Finally, monetary value of environmental loss due to flood prevention works was estimated by using results of CVM and the proposed method in a numerical example, and the effectiveness of the eco-friendly design method was discussed. Copyright © 2014 by the International Society of Offshore and Polar Engineers (ISOPE).

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：Wiley  

A computational method, incorporating the finite element model (FEM) into data assimilation using the particle filter, is presented for identifying elasto-plastic material properties based on sequential measurements under the known changing traction boundary conditions to overcome some difficulties in identifying the parameters for elasto-plastic problems from which the existing inverse analysis strategies have suffered. A soil-water coupled problem, which uses the elasto-plastic constitutive model, is dealt with as the geotechnical application. Measured data on the settlement and the pore pressure are obtained from a synthetic FEM computation as the forward problem under the known parameters to be identified for both the element tests and the ground behavior during the embankment construction sequence. Parameter identification for elasto-plastic problems, such as soil behavior, should be made by considering the measurements of deformation and/or pore pressure step by step from the initial stage of construction and throughout the deformation history under the changing traction boundary conditions because of the embankment or the excavation because the ground behavior is highly dependent on the loading history. Thus, it appears that sequential data assimilation techniques, such as the particle filter, are the preferable tools that can provide estimates of the state variables, that is, deformation, pore pressure, and unknown parameters, for the constitutive model in geotechnical practice. The present paper discusses the priority of the particle filter in its application to initial/boundary value problems for elasto-plastic materials and demonstrates a couple of numerical examples. © 2012 John Wiley &amp
Sons, Ltd.

DOI： 10.1002/nag.2125

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

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DOI： 10.2208/jscejam.69.I_29

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

This research deals with the maintenance strategy of geotechnical structures such as earth-fill dams and river embankments. To determine the soil parameters, the standard penetration test (SPT) N-values are frequently used. Firstly, a statistical model for the N-values is determined from sounding test results. In this research, Swedish Weight Sounding (SWS) tests, simpler than SPT, are employed. Secondly, an indicator simulation is conducted to interpolate the spatial distribution of the N-values, and the results are utilized to find degraded areas inside the embankments and to maintain the embankments. Based on the statistical model for the N-values, the shear strength parameter is derived through the empirical relationships, and then a reliability analysis of the embankments is conducted considering the variability of the internal friction angle. Finally, the effect of improving the embankments is discussed, comparing the calculated risks of the original state with the improved and restored state. © 2013 Taylor &amp
Francis Group, London.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IOS Press  

This research deals with the maintenance strategy of geotechnical structures such as earth-fill dams and river embankments. To determine the soil parameters, the standard penetration test (SPT) iV-values are frequently used. Firstly, a statistical model for the iV-values is determined from sounding test results. In this research, Swedish Weight Sounding (SWS) tests, simpler than SPT, are employed. Secondly, an indicator simulation is conducted to interpolate the spatial distribution of the N-values, and the results are utilized to find degraded areas inside the embankments and to maintain the embankments. Based on the statistical model for the iV-values, the shear strength parameter is derived through the empirical relationships, and then a reliability analysis of the embankments is conducted considering the variability of the internal friction angle. Finally, the effect of improving the embankments is discussed, comparing the calculated risks of the original state with the improved and restored state.

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

Thus far, the focus of studies on seepage failure, known as sand boiling or the piping phenomenon, has been to determine the critical hydraulic gradient or the critical seepage flow velocity. However, the transport of soil after seepage failure also needs to be well investigated in order to estimate the damage to soil structures or the ground. The purpose of this study is to experimentally investigate the relationship between the seepage force and the velocity of the sand particles during sand boiling induced by upward and horizontal seepage flows. In the experiments, silica sand is used as the test material and the migration velocities of the seepage water and the sand particles are calculated from the measured amounts of their discharge. The test results reveal that the equilibrium of the forces exerted on the sand particles, i.e., gravity, buoyancy and fluid-particle interaction, can be successfully used to estimate the velocity of the sand particles subjected to upward seepage flow and that the seepage force needed for the horizontal transport of the sand tends to decrease as the velocity of the sand particles increases.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPANESE GEOTECHNICAL SOC  

Data assimilation is a versatile methodology, developed in the earth sciences, such as geophysics, meteorology, and oceanography, for estimating the state of a dynamic system of interest by merging sparse observation data into a numerical model for the system. In particular, the data assimilation method referred to as the particle filter (PF) can be applied to nonlinear and non-Gaussian problems, and it holds the greatest potential for application to geotechnical problems. The objective of this study is to demonstrate the theoretical and the practical effectiveness of the PF for a geotechnical problem, i.e., applying the methodology to numerical experiments and actual model tests to identify the parameters of elasto-plastic geomaterials. Since the mechanical behavior of soils depends on both the current stress and the recent stress history of the soil, the sampling method called SIS, which can take into account the stress history experienced by soils, identifies the parameters of elasto-plastic geomaterials remarkably well. The results of the numerical tests have shown that the parameters identified by the PF based on the SIS have converged into their true values, and the approach presented in this study has shown great promise as an accurate parameter identification method for elasto-plastic geomaterials. Moreover, the simulation results using the identified parameters were close to the actual measurement data, and long-term predictions with high accuracy could be achieved, even though short-term measurement data were used. The PF approach produces more information about the parameters of interest than simple estimated values obtained from optimization methods. Namely, the identification comes in the form of probability density functions. (c) 2012 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved.

DOI： 10.1016/j.sandf.2012.02.006

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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DOI： 10.2208/jscejam.68.I_317

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DOI： 10.2208/jscejam.68.I_103

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DOI： 10.2208/jscejam.68.I_89

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記述言語：日本語   出版者・発行元：The Japanese Society of Irrigation, Drainage and Rural Engineering  

水の浸透作用によって砂の骨格が破壊し，噴砂が生じる浸透破壊に関するこれまでの研究では，主に浸透破壊の生じる動水勾配や浸透流速を把握することに焦点が置かれてきた．しかし，浸透破壊後の地盤や土構造物の状況を予測するには，浸透破壊時の土粒子の輸送現象を把握する必要がある．本研究では，鉛直上向きの浸透による浸透破壊の際に，浸透流によって運ばれる砂の挙動を実験的に調査した．実験においては，浸透破壊時の浸透水と砂粒子の流出量を分離して測定し，動水勾配と共に浸透流速と砂粒子の移動速度を計測した．その結果からは，透水係数を用いた砂と浸透水との相互作用モデルを用いれば，材料の違いによらず，鉛直方向の力のつり合いによって良好に砂の移動速度を推定できることが明らかとなった．

DOI： 10.11408/jsidre.80.409

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その他リンク： https://jlc.jst.go.jp/DN/JALC/10024829952?from=CiNii

記述言語：英語   掲載種別：研究論文（学術雑誌）  

The limit state design method has been introduced into the design criteria for geotechnical structures.The current paper attempts to apply the reliability-based design method, at Level II, to the bearing capacity of the foundations of open channels from the viewpoint of the limit state design.To examine the applicability of the proposed procedure for practical structures, the reliability index is computed for evaluating the stability of the foundations of existing open channels designed by the conventional method.The conventional design procedure makes excessively safe side design.We applied the first order reliability methods (FORM) to the existing open channels designed by the conventional design procedure, and consequently, large values of reliability index, 3 and 5 were obtained for clayey and sandy soils, respectively.Finally, the partial factors for the soil parameters have been determined, corresponding to the target reliability indices β&lt
inf&gt
t&lt
/inf&gt
=1, 3 and 4. © 2011 Taylor &amp
Francis.

DOI： 10.1080/17499518.2011.558417

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：CRC PRESS-TAYLOR & FRANCIS GROUP  

In this research, the spatial distribution of the strength parameters of decrepit earth-fill dams and an identification method are discussed. Swedish Weight Sounding (SWS) tests are conducted to determine the statistical model to represent the spatial distribution of the N-values. The spatial distribution model can be determined with high resolution from the sounding test results, since point estimations for the N-values are available. The Surface Wave Method (SWM), a geophysical exploration method, is also employed here. It can present the averaged image of the N-value distribution. In this research, these two sets of results are synthesized with the indicator simulation method.

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記述言語：日本語   出版者・発行元：農業農村工学会  

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DOI： 10.11408/jsidre.79.195

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DOI： 10.3208/jgs.6.415

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記述言語：日本語   出版者・発行元：The Japanese Society of Irrigation, Drainage and Rural Engineering  

本研究は，砂質地盤の液状化を対象に，その液状化確率の算定と，リスクの低減を目的とした対策に対して，信頼性設計を実施している．液状化確率は，土質定数の空間的なばらつきを考慮して算定している．第一に，最尤法を利用して，N 値，細粒分含有率F_cの統計モデルを決定し，経験式をとおして動的せん断強度比の算定を行う．これらの確率変数に対して，条件付きシミュレーション法を適用し，地盤の二次元液状化確率の算定を行う．さらに，液状化確率に基づき，最適地盤改良法を決定するための期待総費用最小化に基づく信頼性設計を実施している．地盤改良工法として，サンドコンパクションパイル工法を採り上げ，最適砂置換率を決定している．

DOI： 10.11408/jsidre.79.329

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その他リンク： https://jlc.jst.go.jp/DN/JALC/10010471080?from=CiNii

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

Piping, as the result of internal erosion of embankments, is a primary cause of embankment breaks. Moreover, hollows or cavities of soil structures have been occasionally reported due to erosion within soils. The inner states of embankments are needed to be estimated to take appropriate measures for the prevention of the accidents of soil structures. In this study, simultaneous modeling of the internal erosion and the deformation of soils is carried out. As for the internal erosion, the equations governing the erosion and the transport of fine particles within a soil mass are derived with the concept of erosion rates of soils. Additionally, the constitutive model which can describe the deformation of soils caused by the internal erosion is proposed in this paper. © 2010 ASCE.

DOI： 10.1061/41105(378)11

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：CRC PRESS-TAYLOR & FRANCIS GROUP  

About 50% of dam failures in the world have been triggered by piping, which is a primary cause of embankment breaks. The phenomenon of piping results from the erosion of soil particles and their transport within the soil mass. In this paper, a numerical method to analyze erosion within soils and transport of eroded soil particles is proposed. For the analysis, the saturated-unsaturated seepage flow of the pore liquid, the detachment of soil particles from the soil fabric and the migration of the eroded particles are needed to be considered. As the results of this numerical simulation, the temporal alteration and the spatial distribution of the porosity, the particle size distribution and the concentration of the detached soil particle in the pore liquid, as well as the pore liquid pressure, can be obtained. The results of this analysis have revealed that the method qualitatively predicts the development of piping inside soil structures, such as embankments, as the solutions of the initial and boundary value problem.

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

In this study, a reliability-based design for the improvement of earth-fill dams is presented and the effect of improvement of the embankment for safety against earthquakes is evaluated.An inclined core is considered as the means of improvement for the earth-fill embankment.First, the spatial distribution of the strength of the earthfill materials is discussed, following which the damage level of earth-fill dams is evaluated, using the elastoviscoplastic finite element method (EVP-FEM).By averaging the resulting damage level with the Monte Carlo method, the expected failure costs are calculated.Finally, the effect of this improvement is evaluated by comparing the expected total costs for the original and the restored states of the embankment. © 2010 Taylor &amp
Francis.

DOI： 10.1080/17499511003676655

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：Elsevier BV  

About 50z of the world's dam failures are triggered by piping, which is a primary cause of embankment breaks. The phenomenon of piping results from the erosion of soil particles and their transport within a soil mass. In this paper, a numerical method is proposed to analyze the erosion within soils and the transport of eroded soil particles by adopting the concept of the erosion rate of soils. In such an analysis, the saturated-unsaturated seepage flow of the pore liquid, the detachment of the soil particles from the soil fabric, and the migration of the eroded particles are taken into consideration, and the equations related to the conservation of the pore liquid and the eroded soil particles are numerically solved. This numerical simulation allows for the procurement of the temporal alteration and the spatial distribution of the porosity, the particle size distribution, and the concentration of the detached soil particles in the pore liquid, as well as the distribution of pore liquid pressure. The results have revealed that the method can reproduce the experimental data from previous studies on the internal erosion of soils and that it qualitatively predicts, from the numerical experiments, the typical development of piping within soils, such as soil blocks and embankments, as the solutions to the initial and the boundary value problems of the governing equations.

DOI： 10.3208/sandf.50.471

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記述言語：日本語   掲載種別：研究論文（学術雑誌）   出版者・発行元：農業農村工学会  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：CRC PRESS-TAYLOR & FRANCIS GROUP  

Internal Erosion caused within soil structures, such as earth dams and irrigation ponds, lead to the piping failures of the structures. Most of studies on the internal erosion of soils have been experimental and the computational method to analyze the phenomenon is currently limited. The purpose of this study is to propose the numerical method for solving the internal erosion and the transport of eroded soil particles and to verify the applicability of the method. In this paper, three equations concerning the seepage flow, the change of porosity due to internal erosion and the transport of the eroded soil particles are introduced and computationally solved. The equation of the seepage flow is solved with Finite Element Method, and Finite Volume Method is applied to the equation of the transport of the soil particles. It is shown that the numerical approach can reproduce the experimental date of the previous study.

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DOI： 10.11408/jsidre.77.71

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DOI： 10.11408/jsidre.77.175

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DOI： 10.11408/jsidre.77.191

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記述言語：日本語   出版者・発行元：土木学会  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：CRC PRESS-TAYLOR & FRANCIS GROUP  

A reliability-based design for the improvement of earth-fill dams is discussed in this study, and the effect of improving of the embankment is evaluated in relation to the safety of the embankment against earthquakes. An inclined core is considered here as the means of improvement for the earth-fill embankment. To evaluate the stability of earth-fill dams, the elasto-viscoplastic finite element method (EVP-FEM) is used. Then, combining the Monte Carlo method with the EVP-FEM, the expected damage costs are calculated. Finally, the effect of this improvement is evaluated by comparing the total costs before and after the restoration of the embankment.

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記述言語：日本語   出版者・発行元：農業農村工学会  

DOI： 10.11408/jsidre.77.501

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

The main purpose of this research is to develop a calculation method to assess the probability of liquefaction and a reliability-based design method to mitigate the liquefaction in sandy grounds. The probability of liquefaction is evaluated with the proposed model by considering the spatial variability of the soil parameters and the statistical characteristics related to the occurrence of earthquakes. The liquefaction resistance is calculated from the SPT N-value, the median grain size, D50, and the fines content, Fc, through the empirical relationship [Iwasaki T, Arakawa A, Tokida, K. Simplified procedure for assessing soil liquefaction during earthquakes. Proc Soil Dyn Earthquake Eng Conf 1982
925-39]. The statistical models for these three soil parameters are determined with the maximum likelihood method. The occurrences of earthquakes is modeled based on the maximum annual acceleration found in historical earthquake data records. In this study, the probability of liquefaction is evaluated multi-dimensionally using the cokriging method. Finally, the reliability-based design method is discussed in order to determine the optimum design for ground improvement using sand compaction piles (SCP) based on the calculated probability of liquefaction. © 2006.

DOI： 10.1016/j.strusafe.2006.11.002

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）  

A reliability-based design for the improvement of earth-fill dams is created in this study, and the effect of the improvement of the embankment is evaluated for the safety of the embankment against earthquakes. An inclined core is considered here as the means of improvement for the earth-fill embankment. To evaluate the stability of earth-fill dams, the elasto-viscoplastic finite element method (EVP-FEM) is used. Then, combining the Monte Carlo method with the EVP-FEM, the expected damage costs are calculated. Finally, the effect of this improvement is evaluated by comparing the total costs before and after the restoration of the embankment.

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DOI： 10.11408/jsidre2007.2007.679

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DOI： 10.11408/jsidre1965.2007.201

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DOI： 10.11408/jsidre2007.2007.601

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記述言語：日本語   出版者・発行元：日本コンクリート工学協会  

著しい鉄筋腐食やはつりだし補修過程に伴う鉄筋とコンクリート間の部分的な付着損失を想定し,これに着目した部材のせん断耐力実験を行った。着目した要因は,引張り鉄筋の付着損失本数比および付着損失の範囲の2種類である。実験の結果,これらの部材の耐力は付着の健全なRC部材のせん断耐力値といわゆるアンボンドRC部材の耐力値の概ね間にあった。その特徴について議論した。

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10640283

DOI： 10.11408/jsidre1965.2006.97

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記述言語：日本語   出版者・発行元：The Japanese Society of Irrigation, Drainage and Rural Engineering  

DOI： 10.11408/jjsidre1965.73.7_626

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00377427868?from=CiNii

掲載種別：研究論文（学術雑誌）  

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記述言語：日本語   出版者・発行元：自然災害科学会  

This study was performed to clarify which factors affected damage to tame-ike (small embankment dams for irrigation in Japanese) of northern Awaji Island in western Japan due to Hyogoken-Nambu earthquake. Multivariate and ordinary statistical analyses were carried out for 1788 dams (350 damaged and 1438 undamaged dams which identified using various documents). The model for analysis was created with 11 items and 136 or 100 categories for 4 groups (Location, Geology, Structure, and History of Dam). As a result of analysis, the factors causing to damage for dam in order are (1) distance to the epicenter (9 to 15km, which almost agree to the location of seismic intensity 7 JMA), (2) nearest fault (Nojima, Mizukoshi and D2), (3) embankment volume (the larger the more), (4) angle of crest axis to epicenter (normal or vertical), (5) angle of crest axis to nearest fault (normal or vertical), especially reservoir located backward dam, (6) distance to the nearest fault (less than 750m), (7) elevation of dam site, (8) plan view of dam axis (complicate), (9) surface geology of dam site (soil foundation), (10) leakage, (11) repair. Analysis in this way might be possible to notice the distribution of intensity of seismic force and prediction for damage of embankment.

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10751953

記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：SPRINGER HEIDELBERG  

The phenomenon of hydraulic fracturing is considered to be one of the causes of leakage in fill-type dams. In recent years, it has been found that an estimate of the fracture toughness of a given type of soil could be used as an indicator of the soil's resistance to hydraulic fracturing. One of the problems encountered in its estimation is the assumption that fracture toughness has been theoretically defined for samples of infinite sizes. In this study, laboratory tests were conducted to determine the fracture toughness of samples (of the same size) prepared with initial cracks of various lengths. The main objective was to investigate the relationship of the initial crack length to fracture toughness. The stress distribution around the crack tip for each laboratory test sample was estimated by FEM analysis and by a theoretical equation. These analytical results corresponded reasonably well to results from laboratory tests to determine the appropriate length of the initial crack for the test specimens.

DOI： 10.1007/s10333-004-0036-5

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DOI： 10.11408/jjsidre1965.72.5_377

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出版者・発行元：公益社団法人 地盤工学会  

分割型圧密試験機は,圧密試料内部のひずみや間隙水圧を知ることができ,特に,二次圧密を含む時間依存性挙動の考察のためにしばしば採用される.本研究においても,時間依存性挙動を念頭に置き,上記試験機を用いた圧密試験を実施している.圧密試験は,厚さ2cmの試料を3連結して実施している.実験試料としては,カオリンおよび海成粘土を用いている.一般に,間隙水圧の消散と沈下の進行を比較した場合,水圧の消散の方が速くなる傾向がある.この現象を数値解析を用いてを検証した.ついで,二次圧密現象に対して,弾性モデルに粘性項を付加したモデルを利用し,二次圧密に関するパラメータを同定する方法を示した.

DOI： 10.11512/jiban.JGS39.0.205.0

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出版者・発行元：The Japan Landslide Society  

DOI： 10.3313/jls.41.193

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記述言語：英語   掲載種別：論文集(書籍)内論文   出版者・発行元：Elsevier Ltd.  

This chapter focuses on a multidimensional consolidation inverse analysis. The effects of the measured pore water pressure and the assumption of anisotropy are investigated. An elastoplastic hypothetical ground is analyzed to check the proposed analytical method. The hypothetical observation data are obtained based on the Sekiguchi-Ohtaelasto-plastic model. The effectiveness of the observed pore water pressure is proved
vertical and lateral displacements and pore water pressure are predicted well with the observed pore water pressure. The laboratory anisotropic consolidation tests are also analyzed, because accurate measurements are necessary for the development of the method. The measured deformation and pore pressure obtained in the tests are used for the inverse analysis. According to the results of this analysis
it is shown that the measured pore water pressure and assumption of anisotropy work well, to predict the future consolidation behavior. © 2003 Elsevier B.V. All rights reserved.

DOI： 10.1016/B978-008044268-6/50039-9

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DOI： 10.11408/jsidre1965.2003.559

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記述言語：日本語   出版者・発行元：農業土木学会  

DOI： 10.11408/jsidre1965.2003.815

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出版者・発行元：公益社団法人 地盤工学会  

自然堆積地盤には,通常,異方性が存在すると考えられている.本研究は,粘性土地盤の透水性の異方性を考察しようとするものである.ここでは,鉛直排水および放射排水圧密試験を実施し,鉛直方向および水平方向透水係数の比較を行っている.今回は,練返し試料と不撹乱試料を実験に使用し,その比較も行っている.排水方向の違う圧密試験結果を比較する場合,それぞれ一次圧密に要する時間が違うので,実験から求まる圧密定数を比較するのが難しい.そこで,本研究では,二次圧密を考慮した逆解析を実施し,パラメータの同定を行った.結果,提案法によると,鉛直・水平方向の透水係数の相違が鮮明に評価できることが明らかとなった.

DOI： 10.11512/jiban.JGS38.0.277.0

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：JAPANESE GEOTECHNICAL SOC  

One-dimensional consolidation inverse analysis based on the stochastic nonlinear consolidation model (SNCM) is discussed in this study. The model is determined from the standard consolidation test results, and represents the non-linearity and spatial variability of the coefficient of volume compressibility and the coefficient of permeability simultaneously. Furthermore, the inverse analysis method is proposed on the basis of the SNCM and the finite element method mixed with the Monte Carlo simulation. Measured settlement and pore water pressure are used as observation data in the inverse analysis. The method is applied to the consolidation test results of kaolin clay, and its applicability is confirmed firstly. Then the inverse analysis of an actual soft ground is performed. Future consolidation behavior of the ground is predicted, and the spatial variability and the non-linearity of the consolidation parameters are identified. It is clarified in this study that complicated spatial variability and non-linearity of the consolidation parameters could be considered appropriately in the proposed inverse analysis method, and the method gives accurate prediction of consolidation behavior.

DOI： 10.3208/sandf.42.3_45

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出版者・発行元：公益社団法人 地盤工学会  

DOI： 10.11512/jiban.JGS37.0.337.0

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出版者・発行元：公益社団法人 地盤工学会  

DOI： 10.11512/jiban.JGS37.0.311.0

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出版者・発行元：公益社団法人 地盤工学会  

DOI： 10.11512/jiban.JGS37.0.965.0

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DOI： 10.11408/jsidre1965.2001.423

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DOI： 10.11408/jsidre1965.2001.777

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DOI： 10.11408/jsidre1965.2000.763

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記述言語：英語   出版者・発行元：地盤工学会  

This study was performed to clarify which factors affected damage to tame-ike (small embankment dams for irrigation) in Hokudan Town as a result of the January 17,1995 Hyogoken-Nambu earthquake. Factors were assumed to be : Location (e.g., Distance to Epicenter, etc.), Structure (e.g., Angle to Nearest Fault, Embankment Volume, etc.), Soil Properties of Embankment, Geology of Dam Site and History (Era of Construction, Repaired, etc.). Multivariate statistical analyses were performed for documentary data (damaged : 181,undamaged : 328). Ordinary statistical analyses were conducted for the data investigated in situ for soil properties of the embankment. The results show that the factors causing damage to dam are : (1) Nearest Fault (Nojima, Mizukoshi and D2), (2) Distance to Nearest Fault (less than 500 m), (3) Distance to Epicenter (approximately 8 to 14 km, which almost agrees with the location of seismic intensity 7 JMA), (4) Elevation of Dam Site (higher than 100 m), (5) Embankment Volume (the greater the volume the more damage was caused), (6) Direction of Dam Axis (normal or diagonal to the epicenter or to nearest the fault), (7) Plan View of Dam Axis (3 or 4 axes), (8) Surface Geology of Dam Site (non-cohesive soil type ground), (9) Era of Construction (prior to 1891) and (10) Soil Properties of Embankment (sand, not silty sand or gravel, penetration resistance that is 10% smaller than the undamaged dams).

DOI： 10.3208/sandf.40.6_117

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10423683

記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：A A BALKEMA PUBLISHERS  

This paper discusses the change of the normal stress due to the surface tension and the matric suction of the pore water in unsaturated assemblies of spheres, and also discusses the change of the shear strength of sandy soils with the matric suction. Theoretically derived are the relationships between the change of the normal stress and the matric suction in unsaturated assemblies of regularly/randomly packed equal-sized/non equal-sized spheres. Shear tests with poorly- and well-graded sandy soils were also carried out. Experimental results show the same tendency of the relationships between the change of the normal stress and the matric suction as that from theoretical considerations.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：A A BALKEMA PUBLISHERS  

This paper discusses the coincident effects of rainfall and earthquake on the slope stability. A numerical program for the analysis of the slope instability due to rainfall has been already developed. The program unites a finite element program for the infiltration analysis and a Rigid-Body-Spring-Model (RBSM) program for the slope stability analysis. The numerical results for a model slope show that the reduction of the shear strength of the slope surface soil due to rain infiltration causes the reduction of the safety factor of the slope. When the slope suffers from both rainfall and earthquake, its safety factor will decrease more and it must become more unstable. The effect of seismicity is taken into account by applying the additional horizontal seismic force in RBSM as the pseudo-static limit equilibrium procedure of the slope stability analysis. The calculation results show that the slope suffering from the rain infiltration becomes more unstable when the additional seismic force acts. The greater magnitude of the seismic intensity strongly reduces the safety factor of the model slope.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：A A BALKEMA PUBLISHERS  

This paper discusses the applications of FEM on the basis of the elasto-viscoplastic model to landslide problems. Fluidity parameter gamma which governs the time dependent behavior of landslide, is determined from the comparison of the calculated displacement of landslide with the measured in the Site. Concluding remarks are as follows: 1)The fluidity parameter identified from five typical landslide Sites is within the range of 1*10(-5)similar to 7*10(-4)(day(-1)); 2)The effect of dewatering method was proved by the proposed method; 3)Using this model, it may be possible to make predictions on the future trend of deformation.

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記述言語：英語  

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記述言語：英語   出版者・発行元：農業土木学会  

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：A A BALKEMA PUBLISHERS  

This paper discusses the effect of hysteresis in soil-water characteristic curves of decomposed granite soils on the instability of their unsaturated slopes due to rain infiltration, using the numerical analysis. Almost all soils exhibit hysteresis in soil-water characteristic curves, and the curves are ordinarily measured in the drying process because of the simplicity of measurement. However, the numerical results indicate that the curve measured in the drying process gives incorrect estimates for the slope instability due to rain infiltration. In conclusion, the soil-water characteristic curves of soils should be measured in the wetting process when applied to the slope stability analysis considering rain infiltration.

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記述言語：日本語   出版者・発行元：土木学会  

DOI： 10.2208/jscej.1998.603_101

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：A A BALKEMA  

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記述言語：日本語   出版者・発行元：The Japan Landslide Society  

弾粘塑性FEMによる本解析手法は, 土質試験からのパラメータを用いた解析値と各種移動量の実測値を比較することによって成立しており, 多くの地すべり地の解析に実用的であると思われる。今後の解析事例の集積により地すべり挙動予測への貴重なアプローチとなり得るものと思われる。

DOI： 10.3313/jls1964.31.4_1

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その他リンク： https://jlc.jst.go.jp/DN/JALC/00032119749?from=CiNii

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：MARCEL DEKKER INC  

The retention behavior of five 20-oxosteroids (pregnenolone, 3 beta - hydroxy- 5 alpha -pregnan-20-one, 3 beta -hydroxy- 5 beta - pregnan-20-one, 3 alpha -hydroxy- 5 alpha -pregnan-20-one, and 3 alpha - hydroxy-5 beta -pregnan-20-one) and their sulfates derivatized with 4-(N,N-dimethylaminosulfonyl)- 7-hydrazino-2,1,3-benzoxadiazole were examined using reversed-phase high-performance liquid chromatography with fluorescence detection. Inclusion chromatography using cyclodextrin as a mobile phase additive was also used for this purpose and found effective in separating the isomeric derivatized 20-oxosteroids and their sulfates.

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DOI： 10.11408/jjsidre1965.63.5_513

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記述言語：日本語   出版者・発行元：農業土木学会  

DOI： 10.11408/jsidre1965.1993.35

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DOI： 10.11408/jsidre1965.1992.45

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DOI： 10.11408/jsidre1965.1992.162_1

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記述言語：日本語   出版者・発行元：農業土木学会  

DOI： 10.11408/jsidre1965.1991.154_1

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記述言語：日本語   出版者・発行元：農業土木学会  

DOI： 10.11408/jsidre1965.1991.154_9

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DOI： 10.11408/jsidre1965.1990.150_75

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記述言語：日本語   出版者・発行元：農業土木学会  

DOI： 10.11408/jsidre1965.1988.136_61

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担当区分：責任著者   記述言語：日本語   掲載種別：研究発表ペーパー・要旨（全国大会，その他学術会議）  

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記述言語：英語   出版者・発行元：American Society of Civil Engineers  

DOI： 10.1061/9780784484968

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担当区分：責任著者   記述言語：英語   掲載種別：研究発表ペーパー・要旨（国際会議）  

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担当区分：責任著者   掲載種別：研究発表ペーパー・要旨（国際会議）  

DOI： 10.3850/978-981-18-5184-1_MS-13-067-cd

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担当区分：責任著者   掲載種別：記事・総説・解説・論説等（国際会議プロシーディングズ）  

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担当区分：筆頭著者   掲載種別：研究発表ペーパー・要旨（国際会議）  

DOI： 10.3850/978-981-18-5184-1_MS-13-050-cd

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記述言語：日本語   掲載種別：速報，短報，研究ノート等（大学，研究機関紀要）  

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記述言語：日本語   出版者・発行元：農業土木学会  

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記述言語：日本語   出版者・発行元：日本計算工学会  

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This paper presents the numerical evaluation of the strength and stability of a ground improved via vacuum consolidation combined with a preloading embankment. To assess the stability of soft grounds, the undrained shear strength is definitely required. A numerical analysis is desirable for predicting the strength of the improved ground, and the elasto-plastic FEM for soil-water coupled problems, incorporating the SYS Cam-clay model, is adopted in two dimensions. The compression index of clay and the coefficient of permeability of organic soil, which are the primary factors for evaluating the ground behavior, are identified through an inverse analysis from the measured settlements. As the inverse approach, the particle filter is employed to account for the strong nonlinearity of the ground behavior. A stability analysis of the slip surface method is performed based on the evaluated undrained shear strength to assess the effect of the ground improvement on the construction of earth structures. The results show the validity of the ground improvement using vacuum consolidation with a preloading embankment.

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記述言語：英語   出版者・発行元：Asian Regional Conference on Soil Mechanics and Geotechnical Engineering  

To mitigate the disasters of decrepit earth-fill dams, improvement work is conducted. Since there is a recent demand for low-cost improvements, the development of a design method for optimum improvement work at a low cost is the final objective of this research. The reliability-based design approach is discussed as such a design method. Heavy rains are the most serious events for aged fill-dams, and sometimes overflows leading to breaching occur. From the estimated probability of overflow, the probability of submergence in the downstream is estimated for the reliability-based design. The remarkable point in this paper is that the probability of occurrences of heavy rains and the uncertainty of the soil properties are simultaneously considered for the design. Considering the disaster loss, the risk of submergence could be assessed.

DOI： 10.3208/jgssp.JPN-044

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記述言語：日本語   掲載種別：研究発表ペーパー・要旨（全国大会，その他学術会議）  

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記述言語：日本語   出版者・発行元：一般社団法人日本機械学会  

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記述言語：日本語   掲載種別：研究発表ペーパー・要旨（全国大会，その他学術会議）   出版者・発行元：日本計算工学会  

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記述言語：日本語   掲載種別：研究発表ペーパー・要旨（全国大会，その他学術会議）  

DOI： 10.11345/japannctam.62.0.203.0

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DOI： 10.11345/japannctam.62.0.210.0

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記述言語：日本語   出版者・発行元：地盤工学会  

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記述言語：日本語   出版者・発行元：日本材料学会  

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DOI： 10.11345/japannctam.61.0.54.0

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DOI： 10.11345/japannctam.61.0.55.0

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記述言語：日本語   出版者・発行元：地盤工学会  

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記述言語：日本語   出版者・発行元：農業農村工学会  

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記述言語：日本語   掲載種別：研究発表ペーパー・要旨（全国大会，その他学術会議）   出版者・発行元：日本計算工学会  

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記述言語：日本語  

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記述言語：日本語   出版者・発行元：地盤工学会  

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その他リンク： http://dl.ndl.go.jp/info:ndljp/pid/10420212

記述言語：日本語   出版者・発行元：日本計算工学会  

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記述言語：日本語   出版者・発行元：日本計算工学会  

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記述言語：日本語   出版者・発行元：日本計算工学会  

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記述言語：日本語  

DOI： 10.11345/japannctam.58.0.84.0

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記述言語：英語   出版者・発行元：Graduate School of Environmental and Life Science, Okayama University  

The disposal of large amounts of sludge, deposited in many farm/irrigation ponds in Japan, has recently become an important task to be resolved. To dredge sludge helps to maintain the capacity of the ponds and the quality of the water in the pond. In other words, it is vital that the deposited sludge should be effectively dredged. Since the water content of dredged sludge is very high, it must be reduced to enable the transport and the reuse of the sludge. The authors of the present paper have developed a procedure to dehydrate in-situ dredged sludge from farm ponds using a compact filter press machine. The purpose of this study is to investigate appropriate conditions for the efficient dehydration of dredged sludge with a compact filter press machine. Since the dehydration mechanism inside the filter press machine is based on the hydraulic consolidation, hydraulic consolidation tests are conducted to simulate the filter press consolidation in order to clarify the relationship between the conditions of the filter press dehydration and the water content of the consolidated sludge. Results of the tests show that the most important factor in controlling the efficiency of the actual filter press dehydration process is the thickness of the filtration chamber of the filter press machine. Sludge is expected to be more effectively dehydrated when a filtration chamber with a smaller thickness is adopted.

DOI： 10.3107/jesss.2.21

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記述言語：日本語   出版者・発行元：農業農村工学会  

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DOI： 10.3107/jesss.1.61

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記述言語：日本語   出版者・発行元：土質工学会  

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記述言語：日本語   出版者・発行元：岡山大学環境理工学部  

To examine the possible reuse of dredged sludge in view of construction material, physico-chemical properties and geotechnical characteristics of desiccated sludge are investigated through laboratory experiments. The consistency test, the pH test, the XRF test and the X-ray diffraction analysis are carried out for physico-chemical proteries, and the conolidation test and the permeability test are made for geotechnical characteristics. It is concluded that the history of desiccation changes the consistency of sludge and affects its permeability and consolidation bahavior.

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その他リンク： http://eprints.lib.okayama-u.ac.jp/11438

A calculation method for the probability of liquefaction is shown in this paper. The spatial variability of soil parameters for the liquefaction resistance and the statistical characteristics of earthquake occurrences are considered in the analysis. Furthermore, a reliability-based design of sand compaction piles for ground improvement is discussed.

Scopus

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記述言語：日本語   出版者・発行元：農業土木学会  

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記述言語：英語   出版者・発行元：A A BALKEMA PUBLISHERS  

A two-dimensional consolidation inverse analysis model is discussed in this paper. The effects of the measured pore water pressure and the assumption of anisotropy are investigated. Firstly, an elasto-plastic hypothetical ground is analyzed to check the proposed analytical method. Secondly, the laboratory anisotropic consolidation tests are analyzed, since accurate measurements are necessary for the development of the method. The measured deformation and pore pressure obtained in the tests are used for the inverse analysis. Finally, the method is applied to an actual soft ground problem to verify the applicability of the method to actual problems.

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記述言語：英語   出版者・発行元：MILLPRESS SCIENCE PUBLISHERS  

The dispersion behavior of a substance in the ground water flow depends on the random field characteristics of the permeability. In this study, we clarify how the Gaussian and the non-Gaussian random fields of permeability affect the dispersion behavior. The non-Gaussian random field simulation method is newly proposed in this study. The finite difference method (FDM), combined with the Monte Carlo method (MCM), is used in the analysis to solve the advection and dispersion equations. Firstly, a tracer mixed with water is analyzed as a single-phase problem. Then, the migration of the DNAPL pool in the ground water is treated as a two-phase problem.

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記述言語：英語   出版者・発行元：WORLD SCIENTIFIC PUBL CO PTE LTD  

In many cases, the sludge dredged from the bottom of lakes is dewatered, made into sludge cakes, and then broken into pieces. In this study, the mechanical properties of pieces of sludge cakes to be used as banking material are considered. In particular, their consolidation behavior is discussed here. The following specific problem exists in the consolidation of sludge cake pieces. Since the large voids between the pieces shrink and then the inner void in each piece shrinks due to compression, the conventional consolidation theory is not supposed to be applicable. To understand the consolidation characteristics, large-scale consolidation tests were performed. The applicability of the super-subloading Cam clay model, for the compression behavior, and the least squares method, to identify the coefficient of consolidation, were investigated in this study based on the test results.

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J-GLOBAL

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記述言語：日本語   出版者・発行元：岡山大学環境理工学部  

This study was performed to clarify which factors affected damage to take-ike (small embankment dams for irrigation in Japanese) of Hokudan Town on Awaji Island in western Japan due to Hyogoken-Nambu earthquake. Multivariate and ordinary statistical analysis were carried out using documentary data (181 damaged and 328 undamaged dams), and ordinary one was done for the results investigated in situ. The model for the multivariate analysis was created with 13 items and 94 categories for 4 groups (Location, Geology Structure, and History of Dam). As a result, the factors causing to damage for dam are (1) the nearest fault (Nojima, Mizukoshi and D2), (2) embankment volume (the larger the more), (3) angle of crest axis to epicenter (diagonal and normal), (4) distance to the nearest fault (less than 500 m), (5) distance to the epicenter (8 to 14 km which almost agree to the location of seismic intensity 7 JMA), (6) play view of dam axis (3 or 4 axes), (7) angle of crest axis to nearest fault (diagonal and normal), (8) elevation of dam site (over 100 m), (9) surface geology of dam site (non-cohesive soil), (10) era of construction (prior to 1891), and (11) soil properties of embankment (constructed of sand, smaller penetration resistance).

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記述言語：日本語   出版者・発行元：農業土木学会  

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記述言語：日本語   出版者・発行元：農業土木学会  

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記述言語：日本語   出版者・発行元：岡山大学環境理工学部  

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記述言語：英語   出版者・発行元：A A BALKEMA PUBLISHERS  

The laboratory consolidation tests were performed to investigate the compression characteristics of the dewatered sludge as a construction material. The sludge is dredged from the bottom of a lake. After the dehydration, it is broken into fragments. The fragments shows different compression behavior from that of ordinary undisturbed clay. The remarkable point in our research is: The e similar to log p curves of fragments have two kinds of compression index in the normally consolidation region. The first compression index has linear relation with initial water content, while the second one is almost constant.

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記述言語：日本語   出版者・発行元：岡山大学環境理工学部  

A calculation method of probability of liquefaction is proposed in this paper. The spatial variability of soil parameters for the dynamic shear strength, i.e., N-values, median grain size, fines contents, and the statistical characteristics of the earthquake frequency are considered in the analysis. The standard penetration test (SPT) is convenient to estimate the spatial variability of the dynamic shear strength and mainly used in this study. Furthermore the determination of dynamic shear strength based on Swedish weight Sounding test also introduced here, because it is the simpler test than SPT. While the statistical model of the earthquake frequency is determined based on the record of historical earthquakes. Using this method the probability of liquefaction is calculated. The sand compaction pile method is considered for the ground improvement against the liquefaction. Finally, the relationship between the sand replacement rate and the probability of liquefaction is clarified.

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記述言語：英語   出版者・発行元：A A BALKEMA PUBLISHERS  

The consolidation inverse analysis is carried out in this study by using not only settlement measurement but also pore pressure measurement. A stochastic nonlinear consolidation model (SNCM) is applied to the one-dimensional analysis. The SNCM represents the non-linearity and spatial variability of the coefficient of volume compressibility and the coefficient of permeability at the same time. The method is applied to a model test result, and the effect of pore pressure measurement on the prediction of consolidation behavior is verified. Furthermore, a two-dimensional consolidation inverse analysis is performed by using triaxial anisotropic consolidation test results.

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記述言語：英語   出版者・発行元：A A BALKEMA PUBLISHERS  

The calculation method of the probability of liquefaction is clarified in this paper. The spatial variability of soil parameters for the dynamic shear strength and the statistical characteristics of the earthquake occurrence are considered in the analysis. Secondly, the reliability design of the sand compaction piles for the ground improvement is discussed.

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記述言語：英語   出版者・発行元：岡山大学環境理工学部  

This paper presents a new method for prediction of consolidation settlements of soft grounds. The method is based on the theoretical result which shows that the settlement velocity of soft grounds non-improved or improved with sand drains decreases exponentially with time. Final settlements can be easily derived from the regression analysis for the relationship between the elapsed time and the observed settlement velocity. The method has advantages of its simplicity and capability to give the satisfactorily good estimate of the consolidation settlements, and also the support of the theoretical background.

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DOI： 10.11408/jjsidre1965.63.5_513

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記述言語：英語   出版者・発行元：A A BALKEMA  

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記述言語：英語   出版者・発行元：A A BALKEMA  

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記述言語：英語   出版者・発行元：A A BALKEMA  

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記述言語：日本語   出版者・発行元：岡山大学  

(1)確率有限要素法の二手法である線形近似法とモンテカルロ法についての定式化を示した.特に,モンテカルロシミュレーションについては,一変数一次元確率場と一変数二次元確率場の乱数発生法について示した. (2)ヤング率の自己相関関数を表現するのに必要な要素分割数について考察を行った.その結果,本解析モデルに関しては,10～15分割で変位の平均値,標準偏差が収束することが分かった (3)線形近似法とモンテカルロ法の結果の比較を行った.それによると,線形近似法の結果は,ヤング率の変動係数が0.2の場合まではモンテカルロ法の結果とよく一致するという結論が得られた.ただし,変位の平均値における二手法間での相違は,ヤング率の変動係数が大きい場合でも,本研究の例題に関しては実務上無視しても差し支えないほどの大きさであることが分かった. 本研究の数値計算には,岡山大学情報処理センターのACOS2010,SX-1Eを使用した。

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その他リンク： http://ousar.lib.okayama-u.ac.jp/938

記述言語：英語   出版者・発行元：A A BALKEMA  

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DOI： 10.11408/jsidre1965.1993.35

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DOI： 10.11408/jsidre1965.1992.45

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DOI： 10.11408/jsidre1965.1990.150_75

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DOI： 10.11408/jsidre1965.1988.136_61

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