label: url

en: Proposal of Capacitance Sensors to Detect Immersion and Cavitation

ja: 電線を埋設して浸水や空洞化を検知する静電容量型センサの提案

en: Jiban Kogakkaishi

ja: 地盤工学会誌


en: Validation of Numerical Analysis for Deformation of Clay Ground Based on Uncertainty Quantification

en: Challenges and Innovations in Geomechanics. IACMAG 2021. Lecture Notes in Civil Engineering


en: 粘性土地盤の圧密変形に関する数値解析の検証および妥当性確認

ja: 粘性土地盤の圧密変形に関する数値解析の検証および妥当性確認

en: Journal of Japan Society of Civil Engineers, Ser. A2 (Applied Mechanics (AM))

ja: 土木学会論文集A2(応用力学)


en: 地震で変形した河川堤防の浸透性能評価に関する遠心模型実験

ja: 地震で変形した河川堤防の浸透性能評価に関する遠心模型実験

en: Journal of Japan Society of Civil Engineers, Ser. C (Geosphere Engineering)

ja: 土木学会論文集C(地圏工学)


en: Development of Capacitance Displacement Monitoring System and Its Performance Tests

en: International Journal of GEOMATE

ja: International Journal of GEOMATE


en: In situ measurements using developed high resolution capacitance type sensor and its performance evaluation

en: Proc. of the International workshop on ICT in Geoengineering


en: Damages to River Dikes Due to Tsunami in South-central Coastal Area of Iwate Prefecture in 2011 off the Pacific Coast of Tohoku Earthquake

ja: 2011年東北地方太平洋沖地震における岩手県沿岸中南部の河川堤防の津波による被害の特徴

en: Numbers of river dikes were damaged by the earthquake motion and tsunami in 2011 off the Pacific Coast of Tohoku Earthquake. This paper summarizes the damages on river dikes in middle and southern coastal part of Iwate Prefecture, with the intention of obtaining physical properties of embankment materials to mitigate the damage on river dikes due to tsunami. Damage configurations such as erosion and collapse were investigated along some rivers in the region of tsunami run up from the estuary. The spots, shapes, soil materials and the damage configurations of the river dikes are highlighted. Damages on embankments at the crossing with road bridges or railway bridges were also surveyed. These investigations have revealed that the river dikes protected with concrete facings will suffer less damage, and that even the three-face-armored banks will be subject to erosion in the upstream of the structures such as abutment or water gate.

ja: 2011年東北地方太平洋沖地震では地震動および津波により多くの河川堤防が被災した．本報では，津波による河川堤防被害を軽減するための基礎資料を得ることを目的として，津波被害が顕著であった岩手県中南部の河川堤防の被害状況について報告する．具体的には，岩手県沿岸部の河川を対象として，津波による河川堤防の侵食や破堤の状況を河口部から津波遡上地点までの範囲で調査し，その位置や堤体形状，堤体土質，被災状況についてまとめた．また，道路橋や鉄道橋の取り付け盛土の被災状況も併せて調査した．その結果，表面工のある一般部の河川堤防では被害が小さいこと，橋台や水門などの構造物上流部の河川堤防では表面工があっても侵食される箇所があること，などがわかった．

en: Japanese Geotechnical Journal

ja: 地盤工学ジャーナル


en: Interview investigations on emergency restoration activities of construction companies in the recent damaging earthquakes

ja: 最近の被害地震における建設業の応急対応に関するヒヤリング調査

en: The interview investigations were conducted how the construction companies had conducted the emergency restoration activities in recent damaging earthquakes. In the Niigataken Chuetsu Earthquake in 2004, the information for the restoration works confused because the government, the prefecture and the city had separately communicated to the construction industry. Then, the confusion of information did not occur in Niigataken Chuetsu-oki Earthquake because the construction industry had conferred with the administrator on the correspondence procedure before the earthquake occurred. In the Iwate-Miyagi Nairiku Earthquake in 2008, the local construction companies conducted the emergency restoration on the basis of the disaster cooperation agreement, and greatly contributed to both secondary disaster prevention and the disaster recovery.

en: 安全問題研究論文集

ja: 安全問題研究論文集


en: 岩手・宮城内陸地震及び岩手県沿岸北部地震における企業被害と応急対応

ja: 岩手・宮城内陸地震及び岩手県沿岸北部地震における企業被害と応急対応

en: 21世紀の南海地震と防災

ja: 21世紀の南海地震と防災


en: 重力場，遠心場における水平砂地盤上基礎の支持力実験と変形挙動計測

ja: 重力場，遠心場における水平砂地盤上基礎の支持力実験と変形挙動計測

en: 本研究は，斜面上に設置された浅い基礎の載荷による斜面内の変形形状に及ぼす基礎の載荷位置の影響に着目し，画像解析(CCIP法)による高精度な計測と詳細な観察を行った報告である．


en: 大規模災害に備えた住民自らによる自立的な通信手段の必要性とVoIP アマチュア無線について

en: 21 世紀の南海地震と防災

ja: 21 世紀の南海地震と防災


en: Coupled Analysis of the Behavior of Seabed Subjected to Sea Wave with Different Formulation of Geomaterials

en: The Seventeenth (2007) International Offshore and Polar Engineering Conference


en: Experimental Investigation of Shear Deformation Patterns in Sands Based on Digital Image Correlation

en: Journal of Tongji University

ja: Journal of Tongji University


en: A technique of identifying shear band accurately in granular soil using image correlation analysis

en: Rock and Soil Mechanics

ja: Rock and Soil Mechanics


en: Centrifugal loading tests of adjacent foundations and their FE-analysis using a new elasto-plastic model

en: Physical Modelling in Geotechnics, 6th ICPMG


en: Fourmulation of ground for coupled analysis of seabed response to wave loading

ja: 波浪に対する海底地盤応答の連成解析のための地盤の定式化

en: 第49回地盤工学シンポジウム 平成16年度論文集

ja: 第49回地盤工学シンポジウム 平成16年度論文集


en: Observation of deformation and failure behavior of dense and loose sand grounds under shallow foundation using image analysis

ja: 画像解析による浅い基礎下の密度の異なる砂地盤の変形·破壊挙動の観察

en: 第49回地盤工学シンポジウム 平成16年度論文集

ja: 第49回地盤工学シンポジウム 平成16年度論文集


en: 二重負荷モデルを用いた土の破壊および軟化解析手法の検討

ja: 二重負荷モデルを用いた土の破壊および軟化解析手法の検討

en: 第49回地盤工学シンポジウム平成16年度論文集

ja: 第49回地盤工学シンポジウム平成16年度論文集


en: Deformation behaviour and bearing capacity of sand under two adjacent foundations

ja: 隣接基礎による砂地盤の変形と支持力

en: Journal of Applied Mechanics

ja: 応用力学論文集


en: Deformation field measurement for granular soil model using image analysis

en: Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering


en: Application of image-based measuring deformation method using target markers in physical model test


en: Reappraisal of Size Effect of Bearing Capacity from Plastic Solution

en: A simplified method for estimating the ultimate bearing capacity of surface footings on sand is described with special attention to the dependency of the angle of internal friction of sand on confining stress. An extended slip line method is developed, in which the dependency of the angle of internal friction on the confining stress is formulated from results of conventional triaxial compression tests for various sands. Based on results from a comprehensive series of calculations employing the extended slip line method, the writers reappraise size effects on bearing capacity and investigate the relationship between strength parameters of sand and size effects on bearing capacity. A modified formula and several diagrams that provide a simple estimation method are proposed to consider size effects on bearing capacity. A comparison between estimations using the formula and ultimate bearing capacities measured from several series of centrifuge tests demonstrates the practicability of the proposed method for both strip and circular footings.

en: Journal of Geotechnical and Geoenvironmental Engineering


en: SIMPLE MEASUREMENT OF DISPLACEMENT FIELD OF SAND BY IMAGE PROCESSING

ja: 画像解析による簡便な砂の変位場計測方法

en: The authors developed a simple and general displacement field measuring method using a technique for image analysis. The proposed method, named CCIP method, requires no target installed in the model to measure displacement field on sand. A newly developed correction method for distortion of image needs no longer information than the coordination of four datum points covering the analyzed zone. These features can reduce labor in the preparation of model sand and the analysis of displacement fields. An evaluation of accuracy and two examples are presented in this paper. The results show that the method can measure deformations in sand within an accuracy of 2 pixels of the images employed.

ja: 画像解析による，簡便で汎用的な模型砂地盤の変位場計測手法 を開発した．提案する手法は模型砂地盤表面を撮影した画像間で，相互相関係数を用いたパターン認識により変位を求める手法であり，i)変位場計測のための標点設置が不要である, ii)解析領域を包含する4つの既知点の座標のみを用い，写真撮影や画像取り込み時に生じる画像ひずみの補正が可能である,といった特徴を持つ．そのため，模型実験での変形解析時の省力化が図れ，また過去に実施した実験の変形解析にも適用可能である．本論文では解析原理および計測精度の検証，解析の例示を行い，写真撮影方法を適切に選択すれば，2画素以内の精度で変位計測が可能であることを示す．

en: Journal of Structural Mechanics and Eartquake Engineering

ja: 土木学会論文集(-2005)


en: A Limit Equilibrium Stability Analysis of Slopes with Stabilizing Piles

en: This paper presents a design method for slopes with a row of piles to enhance slope stability or to prevent slope failure. The basic idea of the method is to allow that two different slip surfaces can be assumed in upslope and downslope earth masses of the row of piles. Contrary to the conventional limit equilibrium procedure where a factor of safety is calculated for a given slip surface, in the present method forces acting on the stabilizing piles are estimated based on a given slip surface whose factor of safety is prescribed to ensure the slope stability. By assuming a slip surface in upper and lower earth masses respectively, the forces acting on the piles can be calculated from an existing limit equilibrium method with a prescribed value of the factor of safety. The Bishop method is employed, and a repeated trial proce-dure is used to find the most dangerous situation for the piles and the corresponding two critical slip surfaces in the upside and downside of the pile row. It may be understood that if the stabilizing piles are still sound under the most dangerous situation, then the slope will have, at least, the prescribed (target) factor of safety.

en: SLOPE STABILITY 2000, ASCE Geotechnical Special Publication


en: Prediction of Ultimate Bearing Capacity of Surface Footing with Regard to Size Effects

en: A simplified prediction method based on Terzaghi's bearing capacity formula surface footings with regard to size effects is proposed. The clarification of the size effects, which is indispensable for appropriate design of large foundations, may enable to utilize the results of small scaled loading tests and restrain the construction costs of the foundations increasing. The size effects may be mainly attributed to the stress-level effects on the shear strength of ground materials; the stress-level effects are taken into account in the proposed method. The proposed method incorporates the determination method of shear strength constants and that should be applied to the bearing capacity formula. A nonlinear Finite Element Method which incorporates the confining stress dependent shear strength was used to calculate stress distribution in foundation grounds beneath the footings. It is shown that the effective mean principal stress tends to range from to for strip footings and fromD_ARG1

en: Soils and Foundations

ja: Soils and Foundations


en: Study on the mechanizm of subsidence into the underground cavity in Ohya quarries

ja: 大谷地区空洞陥没のメカニズム

en: A collapse of an underground quarry in Ohya district, located 7km west of the center of Utsunomiya city, caused a large scale subsidence about 3,300m$^2$ wide. Unfortunately, subsequent large scale subsidence has occurred in this district. In order to explain the reason why such large scale subsidence occurred, the authors investigated strength deterioration and creep characteristics, and discussed the mechanism of the collapse. A collapse control with the cross section area and spacing of pillars was also discussed in this paper. According to a correlation between the earth tidal force and the occurrence of subsidence and rock-fall, earth tidal action may trigger collapses of underground quarries under critical states.

ja: 平成元年から同3年にかけて，宇都宮市西郊の大谷石採取場で3,300m$^2$にも及ぶ大規模な地下空洞陥没事故が発生し，その後 引続き陥没事故が発生して社会的関心を集めた． 本論文ではまずはじめに大谷石の力学的性質，特に一軸圧縮強度に及 ぼす乾燥-湿潤履歴とクリープ破壊の影響を調べ，その後陥没のメカニ ズムについて検討し，残柱の断面積と間隔について論じている．更に陥没の発生日時と地球潮汐力との相関を調べ，臨界状態にある空洞に対し地球潮汐力が陥没のトリガーの一つとなり得ることを述べている．

ja: 土木学会論文集(-2005)


en: Design and performance of compact load cell for measuring earth pressure in a centrifuge

ja: 土圧計測用小型門型ロードセルの設計と遠心模型実験への適用について

en: A compact load cell of gate type was newly designed and manufactured, which can be inlaid in a model tunnel for measuring earth pressure on a lining of the shield tunnel in sand. The paper describes its design concept and performance ofthe load cell in a centrifuge. Appicability of three dimensional elsastic FE analysis was also examined and usefulness of the FE analysis was confirmed for studying factors affectiong on strain, such as frictional force and eccentric loading. Non-linearity and hysterisis characteristics of calibration curves were investigated, from which a relationship between diameter of deflecting membrane of the load cell and deflection was deduced to evaluate required rigidity for a certain stress range. Importance of lubrication on side walls of calibration chamber was also demonstrated.

ja: 砂地盤におけるシールドトンネル覆工に作用する土圧計測のため，模型に装着可能な小型門型一方向ロードセルが設計·製作された．

ja: 土木学会論文集(-2005)


en: Centrifuge modeling of shield tunnel construction processes

ja: 施工過程を考慮したシールドトンネルの遠心模型実験

en: Earth pressures acting on lining of a shield tunnel considerably vary with construction processes such as stress conditions around excavation face and grouting conditions. Precise simulation of the construction processes is of essence to examine the pressure development around the lining in a model test. This paper describes the development of a miniature shield machine introduced by high mechatoronics and control technology which can operate under high centrifugal accelerations, simulating the detailed construction processes of shield advancing and tail void formation. The initial set of date demonstrates the significant influence of the construction processes on the final stress distribution around the lining.

ja: シールドトンネル覆工に作用する土圧は，トンネル諸元，地盤条件等が同一であっても，掘削面での載荷あるいは除荷の応力状態や裏込め注入等の個々の施工状態により大きく変化する．このため，模型実験で信頼し得る土圧挙動を検討するためには，施工過程をできるだけ忠実に模擬することが必要となる．本研究では，高度なメカトロニクスおよび制御技術を取り入れた遠心力場で駆動するシールド模型を開発することにより，初期地盤応力状態や掘削，シールド推進およびテールボイド発生の施工過程を考慮した実験による覆工土圧等の計測を試みた．

ja: 土木学会論文集(-2005)


en: Design and development of construction equipment in a centrifuge

ja: 遠心場における施工機械設計法の検討とその妥当性

en: With the advent of modern control engineering and robotics, geotechnical centrifuge technology has reached a stage where sophisticated construction processes could be modeled in a centrifuge. Design and development of reduced construction equipment are necessary to simulate the construction processes. This paper deals with this challenge, describing problems associated with centrifuge modeling involving construction equipments, and experiences of the design and development of miniature shield machine. Validity of the design is examined and consistency of the model test results with field observation is presented.

ja: 土木学会論文集(-2005)


en: Determination of dimension of shear bands produced in granular media

ja: 開放型一面せん断装置を用いた種々の粒状体に発生するせん断層の寸法測定

en: 地盤の破壊とひずみの局所化に関するシンポジウム発表論文集

ja: 地盤の破壊とひずみの局所化に関するシンポジウム発表論文集


en: Structural Capacity of Precast Piles with Grouted Base

en: To improve the performance of a precast pile installed in a prebored hole, a grouted base is often made around the base of the pile. The structural capacity of a precast pile with a grouted base was studied by three series of model loading tests. Two failure mechanisms were observed, punching failure and splitting failure, which depended upon the geometry of the grouted base. Punching failure occurs in cases in which the grouted base is thin, less than twice the pile diameter. In contrast, splitting failure develops in cases in which the grouted base is thicker than twice the pile diameter. Structural capacity increases with increasing the thickness of grouted base. The effect of diameter of grouted base was also examined. Based on the experimental observations, a theoretical model was developed to evaluate the structural capacity. The theoretical prediction agreed well with the experimental results. A parametric study was performed to determine the optimum shape and strength of the grouted base.

en: Journal of Geotechnical Engineering, Proc. of ASCE


en: Nonlinear Finite Element Analysis of Spread Footing Behavior

ja: 非線形有限要素法による直接基礎の挙動解析

en: 第35回土質工学シンポジウム-数値解析による土構造物と基礎の挙動予測-発表論文集