Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Civil Engineers  

In recent years, heavy rains and typhoons have become increasingly severe due to climate change, resulting in accelerated scour of river-crossing bridges supported by shallow foundations. Local scour causes the soil on the upstream side of the pier to be excavated and washed away by the river flow, destabilizing the foundation, and causing it to settle and slope upstream. Therefore, there is a need to improve the accuracy of predicting the extent of scouring damage in advance and the evaluating of bearing capacity after the damage. In this study, we conducted model tests using aluminum rods ground model, through a series of processes from scouring phenomena to bearing capacity tests. The purpose of this study is to propose two methods. The first is to estimate the scour scale that leads to large-scale damage that causes piers to collapse in terms of the bearing capacity of the ground. The other is a method to evaluate the residual bearing capacity after medium-scale damage where residual settlement and tilting have occurred without collapse. As a result, it was shown that the extent of scouring leading to large-scale damage can be quantitatively evaluated in terms of the relationship between the width of the foundation perpendicular to the bridge axis and the height of the center of gravity of the piers, and it was also shown that it is possible to quickly restore the functionality of the bridge (i.e., resume its use) by simple emergency repair of the damaged foundations if the residual eccentricity ratio estimated from the residual inclination angle after medium-scale damage is within 1/10.

DOI： 10.2208/jscejj.24-00088

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Civil Engineers  

In recent years, the damage to the spread foundation piers due to local scouring has been increasing by heavy rainfall and typhoon disasters. If the damage is of a medium scale that causes foundation settlement or tilting, the foundation can be repaired and restored in a short period through emergency restoration. Therefore, in order to make a quicker decision on the restoration of the foundation, it is important to understand the mechanism of the development of the residual bearing capacity. In this paper, the rigid-plastic finite element method (RPFEM) was applied to the bearing capacity problem of the ground after local scouring, in order to evaluate the bearing capacity characteristics immediately after the disaster. In addition to, Meyerhof’s effective footing width was introduced for scoured ground to discuss the analytical results. The numerical results showed that the decrease in ultimate bearing capacity due to scour was mainly due to the effect of the effective footing width and secondarily due to the effect of the slope near the foundation due to scour.

DOI： 10.2208/jscejj.23-15023

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Authorship：Last author,　Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Civil Engineers  

Spiral piles are made by twisting flat steel plates and can be driven by rotary penetration only by human power, so they are expected to be used in construction sites that are so narrow that heavy machinery cannot enter. However, many points are unclear regarding the bearing capacity characteristics of spiral piles, especially regarding vertical pull-out resistance. In addition, the principle of pull-out behavior assumed at actual construction sites has not been fully clarified. Therefore, in this study, a pull-out test of a model pile was conducted using Toyoura dry sand, and the effects of the degree of construction accuracy, such as over-rotation, pushing, and pile shaking during driving, were examined. The effects of the decrease in construction accuracy for pull-out resistance tended to differ depending on the distance between two piles. These are thought to be caused by changes in the ground density around the piles owing to the placement of the piles.

DOI： 10.2208/jscejj.22-15043

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Civil Engineers  

In recent years, along with heavy rainfall, damage to bridge foundations caused by scouring has increased. Even if residual displacement occurs in the foundation, early emergency restoration is realizable if the residual bearing capacity can be retained. A Bayesian inference method for load–settlement curves of shallow foundation after scouring has been proposed previously. This method allows residual bearing capacities to be predicted using light loads. In this study, we use the abovementioned method to estimate the probability of failure during the live loads and investigate the difference in the probability of failure due to the observation error size and number of loading phases.

DOI： 10.2208/jscejj.22-15016

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Chapter of International Geosynthetics Society  

This study investigates the phenomenon of increased earth pressure due to thermal expansion and contraction of girders of integral bridges. Model experiments were conducted using aluminum rod–laminate ground to apply cyclic horizontal loading. Normal and GRS (Geosynthetic Reinforced Soil) integral bridges were used for the experiments, and three patterns of cyclic horizontal displacements—only the active side, both the active and passive sides, and only the passive side—were applied to simulate different seasons when the girder was integrated. The experimental results showed that the reinforcement could reduce the increased earth pressure. The earth pressure at the time of displacement of the passive side increased as the ratio of the displacement of the passive side to the displacement of the active side in cyclic loading increased, regardless of whether reinforcement was used.

DOI： 10.5030/jcigsjournal.37.47

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japan Society of Civil Engineers  

The interaction between the structure and surrounding ground should be appropriately evaluated in the seismic design of cut and cover tunnels. In particular, the shear stiffness ratio (G_g / G_s) between the structure and the surrounding ground is a crucial parameter to evaluate the shear strain ratio (shear strain of the structure γ_s / shear strain of the ground γ_g). However, the effect of the nonlinearity of ground on these relationships has not been clarified. In this study, a model experiment using a small shear tank was conducted using an aluminum rod laminated model ground, which can simulate the nonlinearity of the ground. There are three experimental cases with different structural stiffness. The results are compared with elastic FEM analysis. It is confirmed that the effect of nonlinearity of the ground on the shear strain ratio during an earthquake can be evaluated by modeling the ground with equivalent linear stiffness under the condition of a large shear stiffness ratio.

DOI： 10.2208/jscejseee.78.4_i_613

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)  

In recent years, the damage to bridge foundations caused by heavy rainfall and scouring has increased. In some cases, the entire bridge is carried away, whereas, in others, damage mainly occurs in the foundation, such as settlement and inclination. In the latter cases, it is expected that the damaged bridge is shortly reused after minor repairs are performed only on the superstructure while retaining the residual displacement of the foundation. However, it is difficult to predict whether a foundation with residual displacement possesses the bearing capacity needed to resume emergency use of the damaged bridge. This study focuses on the residual bearing capacity of a shallow foundation after scouring. We performed vertical loading tests on scoured shallow foundations on an aluminum rod ground model to clarify the mechanism. The scouring of the ground was simulated by manually pulling out the aluminum rods. The residual displacement induced by the dead load was measured, and the loading was continued until the residual bearing capacity became clear. We systematically evaluated the effects of scouring volume and shape on the behavior of the foundation. It was found that the residual displacement increased with scouring, but the residual bearing capacity did not necessarily decrease. These findings suggest the possibility of expanding the conditions for the early resumption of damaged foundations and will be helpful for future emergency disaster operations of damaged river bridges.

DOI： 10.21660/2022.98.1472

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Language：Japanese   Publisher：The Japanese Geotechnical Society  

There have been many reports of damage caused by earthquake-induced lateral displacement on an abutment-backfill interface. As such displacement may lead to the derailment of high-speed trains, earthquake countermeasures for existing railway abutments have become an urgent issue, and various countermeasures have been enforced for the Tokaido Shinkansen line since its opening. As per the current design standards, the existing method for constructing earthquake-resistant countermeasures does not necessarily assume Level 2 (L2) seismic activity. In addition, there are limits to the construction environment and construction efficiency, such as construction on tracks being possible only at night and traffic restrictions on the roads near abutments. Therefore, we aim to develop and apply a method for the construction of earthquake-resistant countermeasures to increase the earthquake resistance of existing railway abutments against L2 seismic activity and enable construction work beside abutments during the day. In this study, we developed a countermeasure construction method for railway abutments using reinforcing bars integrated with side walls and verified its effectiveness through tilting tests and model shaking tests. Based on the results, it is confirmed that the sliding mode of the reinforced abutments with the side wall joints is dominant. Moreover, it is possible to improve the maximum resistance of the abutments and limit their residual horizontal displacement and subsidence of the back embankments near the abutments.

DOI： 10.3208/jgs.16.191

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J-GLOBAL

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Language：English   Publishing type：Research paper (scientific journal)  

This publication aims to describe the European and Japanese standards in order to discuss about the ongoing project of revision of the Japanese standard for static pile load tests, keeping in mind that the future version of this standard will have to take into accounts Japanese past experience, as well as the future needs to adapt to overseas practices, if necessary, for economical purposes. To do so, the different derived parameters that can be obtained by carrying out a static pile load test on a vertically loaded pile (instrumented or not) are described. Then, the current practice for static pile load tests in Japan is described, and the main current overseas practices (with an extra focus on the European practices) are inventoried, and their differences (if any) with the Japanese practice are highlighted. Finally, these differences are discussed, and their importance assessed for a possible integration in the future Japanese standard, that could this way be seen for an oversea point of view as viable and legitimate alternative to the other and until now more common practices.

DOI： 10.21660/2020.66.9432

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Language：Japanese   Publisher：公益社団法人 日本地震工学会  

<p>盛土と橋りょうのような構造物境界部は，地震時に橋台背面の盛土が沈下しやすく，バラスト軌道に局所的な沈下が生じて道床横抵抗力が低下する恐れがある．特にロングレール区間で夏季のレール温度が高い状態では，レール軸力が高くなるため，地震時において軌道座屈の発生リスクが高くなる．そこで，地震時の橋台背面盛土部の沈下による軌道の座屈安定性を検討するため，大型振動台を用いて構造物・軌道一体型模型で加振実験を実施した．その結果，盛土の地震対策工により，加振後の橋台天端の水平変位量および橋台背面盛土沈下量を低減することでバラストの沈下が抑制され，軌道の座屈対策工を組み合わせることにより，軌道の座屈を防止できることを確認した．</p>

DOI： 10.5610/jaee.19.5_334

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人 土木学会  

本研究では，橋台における地震時土圧の発現機構を確認するため，実物高さ8mの重力式橋台を想定した縮尺1/8（高さ1m）の模型を用いて，地震波（L1，L2地震動），および正弦波3Hzのステップ加振による振動台実験を行った．加振中は高速度カメラにより橋台，背面地盤の挙動を撮影し，背面地盤に設置した標点の変位を画像解析により求めた．実験結果から，地震時土圧の発現は，背面地盤の応答加速度だけではなく，橋台と背面地盤の間における微小な相対変位が影響していることを確認した．また，地震時土圧，背面地盤の応答加速度，および橋台と背面地盤の相対変位の相関関係は，橋台の高さ位置において異なり，それは橋台と背面地盤の相互の挙動が影響していることが分かった．

DOI： 10.2208/jscejseee.74.i_341

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：土木学会  

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Language：Japanese   Publisher：公益社団法人 土木学会  

土木構造物の効率的な維持管理を行うために，昨今発展しているSfM（Structure from Motion）やMVS（Multi View Stereo）といった多視点画像を用いた三次元モデルの自動生成技術の適用が期待される．しかしながら，三次元モデルの生成には撮影や処理のノウハウが必要であり，適切なモデルを生成するには膨大な時間を要することもある．そこで本取組みでは，SfMをあまり意識することなく撮影された画像を用いて簡易に高精度なモデルを作成する手法を提案し，実験の結果，従来手法より4倍程度の速度で三次元モデルを取得できた．また，時系列三次元モデルを用いた構造物の維持管理における手順や必要な解析機能について示し，その実施例についてまとめた．

DOI： 10.2208/jscejcm.74.i_19

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：GEOMATE International Society  

In recent years, an increasing number of plans in Japan have been proposed for large-scale railway structures to be built deep underground. To construct a large-scale railway structure, it is necessary to construct vertical shafts that serve as the starting and ending point for the shield machine during the construction as well as the air vents once it goes into operation. In such situations, it is expected that there will be an increase in the cases where the vertical shafts will be built to reach deep underground. If typical diaphragm walls were used to construct these deep shafts, the embedment depth of the diaphragm walls would have to be made substantially significant in order to control the heaving. Heaving as stated here is a phenomenon in which pressurized water contained in the permeable layer below the impermeable layer close to the bottom of the excavated ground breaks through the impermeable layer owing to the upward force of the water pressure during the excavation process, which then causes the vertical shaft to lose its stability. Using nodular diaphragm walls that have nodular part on the diaphragm walls of the deep shaft could be relied upon for the purpose of supporting the embedment depth of the diaphragm walls. In this research, the influence the nodular part resistivity was examined in resisting heaving when nodular diaphragm walls are used for the deep shaft. The experiments at gravitational and centrifuge acceleration fields were conducted, and their effectiveness were confirmed.

DOI： 10.21660/2018.46.7265

Scopus

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Language：Japanese   Publisher：公益社団法人 地盤工学会  

地震時に地盤の液状化が発生した場合，地盤は急激に剛性ならびに強度を失うため，基礎構造物にも大きな被害が発生する。施工性・経済性に優れた基礎の耐震補強工法としてシートパイル補強工法が提案されており，普及が進んでいる。液状化地盤における補強効果についても検討は行われているが，矢板内部の液状化抑制に着目されたものが多く，構造的な補強効果については十分に検討されていない。本研究では，模型振動実験を行い，液状化地盤におけるシートパイル補強工法の構造的な補強効果についてメカニズムの解明を行った。また，実務設計で一般的に用いられている2次元の梁ばねモデルを用いた再現解析を実施し高い再現性を得られたことから，既往の設計手法をベースに補強効果が定量的に評価可能であることが示された。

DOI： 10.3208/jgs.12.197

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Language：Japanese   Publisher：公益社団法人 土木学会  

橋台の耐震補強を目的として，背面盛土内に柱列状に地盤改良体（以下，改良体と称する）を造成し，橋台と改良体を連結して一体化する工法に関して，補強効果，補強メカニズムを検証するため，桁重量が大きい重力式橋台を想定した重力場での振動台実験を実施した．その結果，橋台，改良体，および改良体に挟まれた背面盛土が一体となって挙動するため，橋台背面近傍での盛土の沈下量は小さくなり，改良体に生じる水平方向，鉛直方向の地盤抵抗力が連結材を介して橋台の抵抗力として働くことで，橋台の安定性が向上することを確認した．また，崩壊時は改良体の背面側にすべり面が発生して，その範囲が沈下し，橋台は滑動モードで崩壊に至ることを確認した．

DOI： 10.2208/jscejseee.73.I_679

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Language：Japanese   Publisher：国際ジオシンセティックス学会 日本支部  

九州新幹線（西九州ルート）は，武雄温泉～長崎間の延長約66kmの路線で現在建設中である．その中の原種 架道橋は，諫早市内（武雄温泉起点47km263m付近）における短いトンネルが連続した約70mの谷あい部に位置 するPC桁を用いたGRS一体橋梁である．これまでのGRS一体橋梁においては，RC桁やSRC桁を用いた事例はあ るが，PC桁は初めての採用となる．本論文では，これまでのGRS一体橋梁の採用実績を踏まえ，鉄道構造物で 初めての事例となるPC桁を用いたGRS一体橋梁の設計・施工について報告する．

DOI： 10.5030/jcigsjournal.32.153

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：国際ジオシンセティックス学会 日本支部  

九州新幹線（西九州ルート）は，武雄温泉～長崎間の延長約66kmの路線で現在建設中である．その中の原種 架道橋は，諫早市内（武雄温泉起点47km263m付近）における短いトンネルが連続した約70mの谷あい部に位置 するPC桁を用いたGRS一体橋梁である．これまでのGRS一体橋梁においては，RC桁やSRC桁を用いた事例はあ るが，PC桁は初めての採用となる．本論文では，これまでのGRS一体橋梁の採用実績を踏まえ，鉄道構造物で 初めての事例となるPC桁を用いたGRS一体橋梁の設計・施工について報告する．

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Language：Japanese   Publisher：公益社団法人 土木学会  

In this study, methods of aseismic retrofitting were developed for abutments in which soil-mixed column walls were linked to abutments along the sides of tracks. Tilting tests in the gravity field were conducted to confirm the reinforcement effect and mechanisms of the proposed method. Through tilting tests, we confirmed that the stability of the abutments improved due to the ground resistance of the soil-mixed column walls passing through the linking members, working as resistance to the abutment. The ground resistance of the soil-mixed column walls was reproduced using a non-linear spring based on the reinforcing mechanism, and a static non-linear analysis produced results matching the behavior of the tilting tests.

DOI： 10.11532/structcivil.63a.1023

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：国際ジオシンセティックス学会 日本支部  

ジオシンセティック補強土を用いた一体橋梁（GRS一体橋梁）は，桁と橋台（橋台壁）および補強盛土を一体化させる工法であり，補強盛土を含めた不静定構造物である．そのため，橋長が長い橋梁へ適用する場合は，桁の乾燥収縮や温度伸縮等による経時挙動の影響の増大が懸念される．そこで，橋長60mのGRS一体橋梁を対象とした動態挙動の把握を目的として，施工時より変位およびひずみ等の計測を実施している．本稿では，構造物の構築後，約2.5年にわたる計測結果を整理し，経時挙動における構造物の応答特性に関する考察を行った．

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Language：Japanese   Publisher：公益社団法人 土木学会  

斜杭基礎による制震効果には，構造物の慣性力に対する水平抵抗の上昇に加え，地盤変位作用時の逆ロッキング動および入力損失による効果があることが確認されている．一方，近年の高架構造物は，大地震に対して上部工の塑性化によるエネルギー吸収を期待した設計が一般的に行われるが，塑性化が生じた場合にも斜杭による制震効果が発揮されるか検討された例はこれまでにない．本研究では，柱の塑性化を模擬したラーメン高架橋の模型振動実験ならびに数値解析を実施し，柱に塑性化が生じた場合の斜杭ラーメン高架橋の制震効果について検証を行った．結果として，柱端部が塑性化した場合でも斜杭基礎による応答低減効果が発揮されることが確認された．また，この応答低減効果は見かけの有効入力動を用いることで評価可能であることを確認した．

DOI： 10.2208/jscejseee.72.302

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Language：Japanese   Publisher：国際ジオシンセティックス学会 日本支部  

ジオシンセティック補強土を用いた一体橋梁（GRS一体橋梁）は，桁と橋台（橋台壁）および補強盛土を一体化させる工法であり，補強盛土を含めた不静定構造物である．そのため，橋長が長い橋梁へ適用する場合は，桁の乾燥収縮や温度伸縮等による経時挙動の影響の増大が懸念される．そこで，橋長60mのGRS一体橋梁を対象とした動態挙動の把握を目的として，施工時より変位およびひずみ等の計測を実施している．本稿では，構造物の構築後，約2.5年にわたる計測結果を整理し，経時挙動における構造物の応答特性に関する考察を行った．

DOI： 10.5030/jcigsjournal.31.75

DOI： 10.5030/jcigsjournal.37.47_references_DOI_Y1IGLYfyQG0Qo44rm7VdW4EJCHc

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Language：Japanese   Publisher：公益社団法人 土木学会  

斜杭基礎による制震効果には，構造物の慣性力に対する静的な水平抵抗の上昇に加え，地盤変位作用時の逆ロッキング動および入力損失による制震効果が確認されている．静的な水平抵抗上昇による効果は既往の研究により評価されているが，逆ロッキング動および入力損失が構造物全体の応答にもたらす効果を定量的に評価できていないのが現状である．本研究では，直杭および角度5度の斜杭基礎を有するラーメン高架橋模型（約1/10スケール）を用いた振動実験を実施した．その結果，斜杭基礎のラーメン高架橋においては応答低減効果が全周波数にわたって得られることが確認された．また，数値解析を交えた検討により，逆ロッキング動と入力損失が構造物全体に与える制震効果について定量評価した．

DOI： 10.2208/jscejge.71.163

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J-GLOBAL

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Language：Japanese   Publisher：公益社団法人 地盤工学会  

At the soft ground, the earthquakes generate large ground deformations. The large ground deformations displace the pile foundations, and induce the large pile forces at deep location. But it is not clear about the behavior of damaged piles, therefore, piles are generally designed not to be damaged by kinematic and inertial forces. In consequence, piles at soft ground have large diameter and it is difficult to cut off of the longitudinal bars in case of reinforced concrete piles at shallow location. The aim of this paper is to propose the economic seismic design code of pile foundations, and we make a study on the effect of cutting off of longitudinal bars reinforced concrete pile on lateral resistance under kinematic and inertial interactions by model tests and numerical simulations. The results of model loading tests confirmed that the damage at stepped rebar arrangement by ground deformation had no effect on lateral resistance, if the piles are not damaged by inertial forces. And it was possible to simulate the experimentally results by the static nonlinear analysis procedure with seismic displacement method. As a result, it indicated possibility of design considering the damage by ground deformations.

DOI： 10.3208/jgs.10.33

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：土木学会  

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Language：Japanese   Publisher：国際ジオシンセティックス学会 日本支部  

背面盛土を補強土構造とし，橋桁・橋台と一体化させた補強盛土一体橋梁（GRS一体橋梁）が北海道新幹線で実構造物として初めて適用され，施工時および長期動態計測が実施されている．GRS一体橋梁の特徴により，コンクリートの伸縮作用による強制変位により背面盛土内に敷設された補強材（ジオテキスタイル）に引張変位が多数繰り返し生じる．また，アプローチブロックの背面方向への変位が生じることで補強材に対して引張変位が作用する可能性が懸念される．本論文では，長期動態計測より得られたデータを整理し，補強材の引張変位に影響を与える橋梁部の伸縮挙動と背面盛土（セメント改良アプローチブロック）の沈下状況について，実構造物の挙動を踏まえて考察した．

DOI： 10.5030/jcigsjournal.29.205

DOI： 10.3208/jgssp.igs-03_references_DOI_1KecR5QJvw2GP1X9b9A4ElA8z3l

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Language：Japanese   Publisher：国際ジオシンセティックス学会 日本支部  

ジオテキスタイルの表面は繊維の編み込みにより平滑でなく，ひずみゲージを直接貼り付けることが困難で あるため，塩ビフィルムを介してひずみゲージを貼り付ける場合がある．本論文ではこの方法によるひずみの 計測精度について検証した．気中引張試験時および土中引張試験時に得られたひずみゲージの出力特性は，定 量的には気中および土中といった環境条件により大きく異なり気中引張試験時の画像解析から求めた真のひず みよりも小さな出力となることが分かった．ただし，荷重とひずみには概ね線形的な関係が得られており，同 様の環境条件にあるひずみゲージ間での定性的な比較（例えばひずみ分布形状や影響範囲に対する考察）につ いては，問題なく評価が可能であることが確認できた．

DOI： 10.5030/jcigsjournal.28.221

DOI： 10.5030/jcigsjournal.31.75_references_DOI_XvlSCrp907eEGy3GpZypuTQKApI

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Language：Japanese   Publisher：公益社団法人 土木学会  

杭の鉛直ばね定数は重要な設計指標であるが，供用時の杭の変位自体は微小な値であるため実際の変位挙動は十分に明らかになっていない．特に使用性を議論する上では杭の鉛直ばね定数の変位レベル依存性を評価する必要があるが，列車通過時の微小な変位レベルから鉛直載荷試験での大きな変位レベルまでの連続的に検討した例はこれまでほとんどなかった．そこで，本研究では杭基礎を有する鉄道ラーメン高架橋を対象に，同一箇所において建設段階での実杭の鉛直載荷試験と開業後の列車通過時の高架橋柱下端の動的変位計測により，鉛直ばね定数を実測し両者の関係を比較・考察した．その結果，列車通過時の鉛直ばね定数と変位増分の関係は，鉛直載荷試験での鉛直ばね定数の変位レベル依存性を外挿して連続的に評価可能であることを確認した．

DOI： 10.2208/jscejge.67.78

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Language：Japanese   Publisher：公益社団法人 土木学会  

ケーソン基礎頂版は，地震時に作用する慣性力を，ケーソン基礎の側壁に伝達する部材である．現行の頂版のせん断耐力式は，橋脚く体に対して作用する曲げモーメントと軸力により，橋脚く体基部に生じる圧縮力を偏心軸力で模擬した，頂版の載荷実験結果に基づいて提案されている．しかし，実験で用いられた模型は，実際の構造物を単純化したもので，境界条件や載荷条件が異なることから，頂版の耐荷機構を十分に解明できていない可能性がある．そこで，橋脚く体と側壁を連結してモデル化した，頂版の載荷実験と有限要素解析を実施した．その結果，頂版内部の破壊面の形状が，従来の想定とは異なることが判明した．これに基づき，頂版の耐荷機構を明らかにするとともに，新たなせん断耐力評価法を提案し，本実験結果を概ね評価できることを確認した．

DOI： 10.2208/jscejmcs.67.57

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Language：Japanese   Publisher：公益社団法人 地盤工学会  

The rigid frame viaduct is used for railway structures. But it is sometimes problematic on the train-running safety in the seismic conditions because of the differential displacement with adjacent structure by its low horizontal stiffness. The batter pile is one of the measures to gain the horizontal stiffness of the viaduct and expected to secure the train-running safety. But it has not been used recently for the railway and there are many unknown matters such as characteristics of lateral resistance in the case of earthquake. In this study we clarified the characteristics of lateral resistance of batter pile based on the static and dynamic non-liner analyses and experiments. And we studied its applicability for the railway structure. We studied the relatively acute-angled batter pile and found that it can control the horizontal displacement of structures and shorten the equivalent natural period even for the batter piles with the angle of approximately 5 degrees. Furthermore, it can also have not only seismic but also economical advantage in the case that train-running safety becomes the decisive factor of the structure’s specifications.

DOI： 10.3208/jgs.5.293

DOI： 10.2208/jscejseee.76.4_i_75_references_DOI_QQULYl78wFFNhZgHDMUaYD8I62J

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Language：Japanese   Publisher：公益社団法人 地盤工学会  

建設年代の古い構造物基礎には耐震性能に劣り，耐震補強工事が必要なものが多く存在する。既設橋脚基礎のフーチングを取り囲むようにフーチング幅程度の根入れのシートパイルを打設し，既設フーチング上面に増しフーチングを打設してシートパイルを既設橋脚と一体化させるだけでも，一定の耐震補強効果が期待できると考えられる。本論文では約1/10スケールの模型を用いた静的載荷実験および振動実験に基づき，その耐震補強効果を明らかにするとともに，その補強効果発現メカニズムについて考察する。提案補強工法は，主に既設の杭に発生する断面力が大きく低減する効果が期待できることが確認でき，特に杭頭だけではなくシートパイルを根入れさせた深度よりも深い地中部の断面力も低減できることを確認した。その抵抗メカニズムは，シートパイルを介した水平地盤抵抗が発現されることにより，杭に作用する地盤反力が低減されることと考えられる。

DOI： 10.3208/jgs.5.251

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人 土木学会  

In this study, we proposed the new methodology to evaluate the behavior of a pier with a caisson foundation under strong earthquake by means of a push-over analysis. Firstly, we showed that we can hardly estimate the dynamic response of the pier with caisson foundation accurately using the static analysis without considering the inertial force of foundation. Secondly, we proposed the simple push-over analysis, taking into account the influence of the inertial force of foundation. Finally, we clarified through dynamic and the static analysis that the proposed method estimates the dynamic behavior of the caisson structure in a good accuracy.

DOI： 10.11532/structcivil.56a.227

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：土木学会  

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Language：Japanese   Publisher：公益社団法人 土木学会  

筆者らは，フーチング掘削時の仮土留め用鋼矢板を本設利用する鋼矢板併用直接基礎（シートパイル基礎）を提案している．シートパイル基礎は，鋼矢板の地盤拘束効果による高い支持力および地震時の水平抵抗特性が期待できることから，直接基礎に比べて広い範囲の地盤条件へ適用が可能である．本論文では，シートパイル基礎の実大規模の水平載荷試験として，実大模型に対して極限まで載荷した事例（事例1） と，実構造物に対して橋脚のひび割れ限界まで載荷した事例（事例2）について示す．事例1では，同一寸法の直接基礎との比較により，これを上回る高い水平抵抗特性を確認した．事例2でも，耐震設計で想定する以上の十分な水平抵抗特性を有することを確認した．

DOI： 10.2208/jscejc.65.363

DOI： 10.2219/rtriqr.52.51_references_DOI_U2D7C5d7Xhnedw4Om8HIvAMq2De

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：公益社団法人 土木学会  

これまで杭基礎の鉛直地盤抵抗の設計値は，主に静的な鉛直載荷実験に基づいて評価されてきた．しかしながら，大地震時のように大きな載荷速度を有する動的な鉛直荷重が杭基礎に作用する場合，従来の静的な鉛直載荷実験に基づき評価された場合と異なる沈下・鉛直地盤抵抗特性を示すことが知られている．そこで本研究では，杭模型に対して静的・動的鉛直載荷実験の実施，および骨組み解析モデルに基づく数値解析的アプローチにより，動的鉛直荷重が杭に作用した際の沈下・鉛直地盤抵抗特性の解明を行った．その結果，杭の支持形態により減衰特性が異なること，除荷点を把握することで減衰定数を定量的に評価でき，簡易な骨組み解析モデルにより，模型載荷実験で得られた杭の動的な沈下・鉛直地盤抵抗を概ね評価できることが分かった．

DOI： 10.2208/jscejc.64.756

DOI： 10.2208/jscejge.68.117_references_DOI_A0T79byWJpvDmp0qZBEIsHi9nfd

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Language：Japanese   Publisher：公益社団法人 土木学会  

シートパイル基礎は，直接基礎のフーチング4辺にシートパイルを配置，結合した新しい基礎形式であり，地中に貫入，結合されたシートパイルの地盤拘束効果による支持力向上と，地震時の転倒及び滑動耐力増加が期待できる．本研究では，遠心模型振動実験によりシートパイル基礎の初期剛性が同規模の直接基礎に対して大きく増加すること，地震時の応答変位を低減できることを示した．また，シートパイル基礎の初期剛性はシートパイルの根入れ長や基礎地盤密度に影響を受けること，シートパイルとフーチングを剛結構造にしないと最大強度の増加は期待できないことがわかった．さらに，その耐震抵抗メカニズムを分析し，振動方向に対して前・背面シートパイルの押し込み・引き抜きによるフーチング底面中央周りの回転抵抗の寄与が支配的であることを示した．

DOI： 10.2208/jsceja.64.665

DOI： 10.2208/jscejc.65.363_references_DOI_GuJZ7gK9AL571Blc9D4Xc9VJInK

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Language：Japanese   Publisher：公益社団法人 土木学会  

筆者らは，仮土留め用鋼矢板を本設利用する鋼矢板併用直接基礎（シートパイル基礎）を提案している．シートパイル基礎は，鋼矢板による地盤拘束効果等の補強効果が期待できることから，従来は直接基礎では支持力不足となるN値30未満の地盤においても杭が不要となる．本研究では，このシートパイル基礎の鉛直支持力特性を把握するため，模型地盤における静的鉛直載荷実験を行った．その結果，直接基礎に比べて極限支持力が上昇し，ピーク荷重後の荷重低下幅が抑制される改良効果が確認できた．また改良効果の発現メカニズムについて考察を行い，シートパイルによる地盤拘束による支持力の上昇効果だけではなく，地盤とシートパイル側面の拘束が強まり周面摩擦力が上昇する効果が期待できることを明らかとした．

DOI： 10.2208/jscejc.63.772

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Language：Japanese   Publisher：公益社団法人 土木学会  

マルチスケール解析法の一般的な枠組みに基づいて，岩盤のように分布亀裂を含む物体の力学挙動を扱うために，亀裂面の摩擦接触を考慮した非線形マルチスケール解析法を構築した．亀裂の摩擦接触解析については，Lagrange未定乗数法と鞍点定理に基づいた定式化と有効制約条件法による解析アルゴリズムを示した．規則的な平行亀裂群を有する不連続性岩盤モデルを想定した平板載荷試験とブロックせん断試験の解析を行い，亀裂の摩擦接触挙動を考慮したマルチスケール解析法の岩盤構造物への適用可能性を示した．

DOI： 10.2208/jscejc.62.57

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A numerical scheme to evaluate the elastic stiffness and strength of heterogeneous material, which have been proposed by authors based on the theory of homogenization, is applied to fiber reinforced composites, and its validity for evaluating their mechanical properties is examined. Results show that the numerical scheme can give fairly good predictions as for the elastic stiffness, but it can only predicts value of strength near to the experimental data since the numerical scheme does not take the existence of initial defects in the composites into account. However, it can conclude that our proposed method can use for evaluation of mechanical property of composite material at some first stage of design since the method needs only the mechanical properties of each materials of which the composite consists and a graphical data representingthe geometric feature of the composite structure.

DOI： 10.2208/journalam.2.449

DOI： 10.1299/transjsme.16-00581_references_DOI_C2AQ99yJNteOPdPjJuDsVQHMJNj

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Springer Nature Singapore  

Integral bridges can eliminate economic and structural weaknesses by integrating reinforced concrete abutments and girders. However, owing to thermal expansion and compression of the girders under changing atmospheric temperatures, a bridge can be damaged from increased backfill earth pressure resulting from repeated horizontal displacement of abutments. Therefore, the thermal expansion and compression of bridge girders must be considered when designing integral bridges. Climate change associated with global warming may result in extreme temperature changes. Thus, bridge girders may have a higher thermal expansion and contraction compared to those in previous design assumptions. Therefore, we investigated the possibility of quantitatively evaluating the increasing earth pressure caused by the thermal expansion and contraction of bridge girders. This study entailed simulations of the repeated horizontal displacements of the bridge abutments using an aluminum bar laminate model. We obtained the results of 100 cyclic loading tests, which showed that the maximum value of the earth pressure at the end of the cyclic loading is minimally affected by the position of the amplitude center, and it can be predicted from the load–displacement relationship for non-repeated loading. Therefore, based on the results of the non-repeated load tests, the maximum value of the earth pressure resulting from repeated horizontal displacement of abutment can potentially be incorporated into the design of integral bridges.

DOI： 10.1007/978-981-99-9223-2_4

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Springer Nature Singapore  

Owing to climate change, localized heavy rainfall and typhoons have become increasingly dangerous in recent years, leading to accelerated scour and causing damage to river-crossing bridges supported by shallow foundations. Most studies on bridge scour have mainly aimed to evaluate the ground outflow area from a hydraulic perspective, but only a few have focused on the relationship between such an area and the displacement or residual bearing capacity of the foundation, which is necessary to assess the performance of foundations after flooding events. Our previous study focused on local scour caused by the concentrated removal of ground from the upstream edge of the foundation. This study focuses on internal erosion, where fine soil particles flow out of the layer just beneath the foundation. To evaluate the residual bearing capacity after internal erosion, we conducted vertical loading tests of internally eroded shallow foundations using an aluminum rod ground model from which only the small-diameter aluminum rods were extracted to simulate the phenomenon. The test results showed that: (1) residual settlement occurred immediately after the event causing internal erosion; (2) there was no significant increase in the residual slope angle; and (3) the residual bearing capacity did not decrease during emergency repairs, such as the replenishment of the residual settlement with concrete.

DOI： 10.1007/978-981-99-9223-2_14

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Language：English   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：Springer Nature Singapore  

The sheet pile (SP) reinforcement method can be utilized to realize a sustainable society because it is more economical, environment friendly, and easier to construct in narrow areas than conventional methods of reinforcing pile foundations. Furthermore, the method can be used as a foundation reinforcement technique. In this study, static horizontal loading tests were conducted on a model ground using various separations between the piles and SP. Additionally, we studied the effects of increasing the overall resisting force of the foundation and the effect of decreasing the load supported by the existing piles. The results confirmed that when the distance between the existing piles and SP is small, the SP reinforcement effectively reduces the cross-sectional forces acting on the existing piles. By contrast, when the separation is large, the SP reinforcement effectively increases the bearing capacity of the entire foundation. Thus, the interaction between the pile and SP perimeter soil changed when the separation varied, and the reinforcement effect varied with the separation.

DOI： 10.1007/978-981-99-9215-7_10

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Language：Japanese   Publishing type：Rapid communication, short report, research note, etc. (scientific journal)   Publisher：The Japanese Geotechnical Society  

Small displacements of Shinkansen viaducts can be fatal for running safety. Therefore, not only ultimate bearing capacity but settlement is an important verification index of the foundation structures. The plain area at Omura city in Nagasaki prefecture, located between Takeo-onsen and Nagasaki station of the Kyushu Shinkansen, is composed of unusual soil, that is sandy gravel with coble stone, and the Shinkansen viaducts have not been constructed on such type of the soil. In addition, the soil in Omura was not simply considered as a bearing stratum for the shallow foundations because N-values from the standard penetration test varied widely, and the minimum was 20. However, shallow foundations have a cost advantage over other foundation types like pile foundations. Therefore, the authors examined the application of shallow foundations in this site with the in-situ test, self-boring typed in-situ friction tests, plate loading tests, and triaxial tests using the specimens sampled by gel push method. As a result, the design values of the soil were suggested, and the performance required for shallow foundations was verified with the proper management method.

DOI： 10.3208/jgs.18.223

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In Torrential Rain in Northern Kyushu region in Japan in July 2012, the foundation of a railway bridge across a small river settled approximately 0.3 m because of scouring. In this study, detailed investigations or tests, and simple repairs (jacking up of girders and track maintenance) were performed, and the slow-speed train service resumed approximately a month following the incident. Changes during this period in the reliability of the bridge bearing capacity were assessed by Bayesian updating with a particle filter.
The calculation results quantitatively indicated that the reliability index  decreased because of the damage and that the parameter value increased with more information, which revealed the validity of the engineering decisions during the damage restoration periods. It is expected that weather hazards will intensify in the future. Hence, the present findings can be used in the rapid recovery of structures that are subject to similar damage.

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Geosynthetic-Reinforced Soil (GRS) integral bridge was developed and constructed for the first time in Japan. A pair of GRS retaining walls (RWs) are first constructed as the main component of a pair of abutments. After the deformation of supporting ground and backfill has taken place sufficiently, a RC full-height rigid (FHR) facing is constructed by casting-in-place concrete directly on the wall face wrapped-around with geogrid layers reinforcing the backfill in such that the facing is firmly integrated to the reinforced backfill. Finally, a girder is constructed with both ends structurally integrated to the top ends of the FHR facings. Due to very-high cost effectiveness with excellent performance against not only severe seismic loads but also long-term train loads requiring minimized maintenance work, this technology has been well accepted by railway engineers in Japan. Potential problems due to annual thermal deformation and long-term concrete dry shrinkage of the girder and severe seismic loads become more serious as the span becomes longer. Several measures were developed to alleviate these problems by performing a series of cyclic loading tests on a full-scale partial model comprising a FHR facing, a buffer zone and part of approach block. The relevance of the structural design and construction method was confirmed by monitoring long-term performance of a GRS integral bridge with a span of 60 m.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本鉄道施設協会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：総合土木研究所  

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Language：Japanese   Publisher：総合土木研究所  

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Language：Japanese   Publisher：総合土木研究所  

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Language：Japanese   Publisher：鉄道総合技術研究所  

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Language：Japanese   Publisher：鉄道総合技術研究所  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：総合土木研究所  

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Language：Japanese   Publisher：研友社  

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Language：Japanese   Publisher：日本鉄道施設協会  

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Language：Japanese   Publisher：地盤工学会  

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Language：Japanese   Publisher：日本鉄道施設協会  

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Language：Japanese   Publisher：日本鉄道施設協会  

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Language：Japanese   Publisher：土木学会  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：地盤工学会  

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Language：Japanese   Publisher：総合土木研究所  

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Language：Japanese   Publisher：地盤工学会  

In this paper, the non-destructive examination method of the pile by vibration exciter is proposed. Natural frequency can be found by the pile head resonance test using small vibration exciter. Furthermore, coefficient of lateral subgrade reaction is identified by eigenvalue analysis. In addition, it is the feature of a resonance test using vibration exciter that displacement amplitude under resonance can be measured. By using the new evaluation model of displacement-level dependence for coefficient of lateral subgrade reaction, the coefficient in a resonance test is convertible for the coefficient in the displacement level of a structural design.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：総合土木研究所  

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Language：Japanese   Publisher：総合土木研究所  

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Language：Japanese   Publisher：総合土木研究所  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：総合土木研究所  

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J-GLOBAL

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.   Publisher：研友社  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.   Publisher：研友社  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本鉄道施設協会  

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Language：Japanese   Publisher：Architectural Institute of Japan  

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Language：Japanese   Publisher：Architectural Institute of Japan  

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Language：English   Publisher：Japanese Geotechnical Society  

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Language：Japanese   Publisher：総合土木研究所  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：日本鉄道施設協会  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.   Publisher：中央復建コンサルタンツ  

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J-GLOBAL

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J-GLOBAL

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：地盤工学会  

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Language：Japanese   Publisher：総合土木研究所  

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Language：English   Publisher：公益財団法人 鉄道総合技術研究所  

The design bearing capacity of piles can be calculated by multiplying the characteristic value with its corresponding resistance factor. In this study, we proposed a method for calculating these parameters from a loading test database of several different construction methods. Initially, we proposed the formula for calculating the characteristic value by using results from a ground investigation. Secondly, we proposed the resistance factor obtained from the statistical analysis of the loading test database by use of the first-order reliability method. The proposed method can be used to compare the effectiveness of various pile construction methods with the same reliability.

DOI： 10.2219/rtriqr.52.34

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Language：English   Publisher：公益財団法人 鉄道総合技術研究所  

It is well known that the earthquake response of a pile-supported structure is strongly affected by dynamic soil-pile interaction. When the structure is subjected to severe ground motion, the soil behaves in a nonlinear manner. Two kinds of soil nonlinearity will affect the characteristics of dynamic soil-pile interaction. One is the nonlinearity which appears in the soil surrounding the pile and the other is the nonlinearity which appears in the free-field. The nonlinearity of soil surrounding the pile is caused by the inertia force transmitted from the superstructure onto the pile head (i.e., local-nonlinearity). Soil nonlinearity in the free-field is caused by the transmission of shear waves (i.e., site-nonlinear ity). Various tools based on the Sway-Rocking model have been developed to analyze nonlinear dynamic soil-pile interaction. Most of these methods, however, only take into account local-nonlinearity effects. Therefore, a methodology to evaluate the effects of both local-nonlinearity and site-nonlinearity are developed in the paper. The accuracy of this method is confirmed by comparing simulated and experiment results.

DOI： 10.2219/rtriqr.52.45

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：地盤工学会  

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Language：Japanese   Publisher：地盤工学会  

The rigid frame viaduct is typically used for railway structures. But it is sometimes problematic on the train-running safety because of the differential displacement with adjacent structure by its low horizontal stiffness. We noticed the batter pile foundation to gain the horizontal stiffness of the viaduct, and numerical analyses and model experiments were carried out. This paper shows that the batter pile foundation has excellent seismic resistance, and it can control the horizontal displacement of structures and shorten the equivalent natural period even for the batter piles with the angle of approximately 5 degrees.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：地盤工学会  

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Language：English   Publisher：Japanese Geotechnical Society  

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Language：English   Publisher：公益財団法人 鉄道総合技術研究所  

The authors propose sheet-pile foundation as a new viable foundation structure. The construction costs of this type of foundation are lower than those for pile foundation, and it can be used more widely than shallow foundation. In this research, a series of laboratory static loading tests and full-scale field tests were carried out to evaluate the fundamental characteristics of sheet-pile foundation. The tests showed that its horizontal resistance is larger than that of shallow foundation, and that it exhibits excellent performance against seismic forces.

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Language：Japanese   Publisher：研友社  

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Language：English   Publisher：Japan Society of Civil Engineers  

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：土質工学会  

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.   Publisher：鉄道・運輸機構鉄道建設本部  

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Language：Japanese   Publisher：総合土木研究所  

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Language：Japanese   Publisher：地盤工学会  

The authors have proposed the "sheet-pile foundation" which combines the footing and sheet-piles as a new reasonable foundation structure. This foundation can be constructed at a lower cost than the pile foundation, and be used more widely than the shallow foundation. In this research, in order to grasp bearing capacity and aseismatic peformance of the sheet-pile foundation a series of static loading tests and centrifuge shaking table tests are conducted on a model of the shallow foundation and sheet-pile foundation. It is shown that the sheet pile-foundation is the excellent in performance for seismic force.

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Language：Japanese   Publisher：埼玉大学地域共同研究センター  

Detecting the damage to the foundations embedded in soil layers is rather difficult when compared with the detection of the damage to the superstructures. Therefore. this study develops a damage-detector device utilizing the piezoelectric materials for the detection. In this study, the effect of this device upon the structural member is verified by using Finite Element Technique, The results of the analyses show that the existence of the device in the structural member has little effect upon the strength and the ductility of the structural member.

DOI： 10.24561/00016747

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Language：English   Publisher：Southeast Asian Geotechnical Society  

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Language：Japanese   Publisher：研友社  

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Publisher：The Japanese Geotechnical Society  

A new bridge foundation named "Sheet-pile foundation" is proposed. Sheet-pile foundation consists of a footing and sheet piles surrounding the footing. By installing sheet piles into the ground around the footing and connecting together, both overturning and sliding resistance of the foundation against the seismic action will be increased.In this paper, 6 different foundation models, which consist of the sheet-pile foundations with 5 different connection systems and a conventional spread foundation, were tested under 50g centrifugal gravity, and the seismic performances were compared.

DOI： 10.11512/jiban.JGS39.0.1815.0

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Publisher：The Japanese Geotechnical Society  

DOI： 10.11512/jiban.JGS39.0.1421.0

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Publisher：The Japanese Geotechnical Society  

A new bridge foundation named "Sheet-pile foundation" is proposed. Sheet-pile foundation consists of a footing and sheet piles surrounding the footing. By installing sheet piles into the ground around the footing and connecting together, both overturning and sliding resistance of the foundation against the seismic action will be increased.In this paper, effect of length of the sheet pile was investigated as well as the mechanisms of its seismic resistance. 1/25 scaled models with rigid connection system were tested in this case.

DOI： 10.11512/jiban.JGS39.0.1817.0

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Publisher：The Japanese Geotechnical Society  

DOI： 10.11512/jiban.JGS39.0.77.0

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Language：Japanese   Publisher：埼玉大学地域共同研究センター  

Detecting the damage to the foundations embedded in soil layers is rather difficult whencompared with the detection of the damage to the superstructures. Therefore, this study develops a damage-detector device utilizing the piezoelectric materials for the detection. The performance of this device is verified by conducting RC-beam bending tests. The results of the tests exhibit a good correlation between the response of the device, which is compatible to the voltage due to the electric polarization, and the response ductility of the damaged RC-beam specimen.

DOI： 10.24561/00016718

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Publisher：The Japanese Geotechnical Society  

DOI： 10.11512/jiban.JGS39.0.1423.0

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Language：Japanese   Publisher：社団法人地盤工学会  

It is difficult and is not efficient to detect damage to the underground structures by conventional damage detection method used for the usual maintenance of railway structures on the ground such as girder and pier. In this study, a new method using intelligent material was established to make it possible to detect damage to foundation with simplicity and cost effectivity Further, vertical loading tests against concrete specimen in which three different types of intelligent material were installed were carried out The experiments revealed that all intelligent materials employed in this study can certainly detect damage to the specimen.rights: 社団法人地盤工学会rights: 本文データは学協会の許諾に基づきCiNiiから複製したものであるrelation: IsVersionOf: http://ci.nii.ac.jp/naid/110003889738/

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Language：Japanese   Publisher：地盤工学会  

Taking into account both needs of foundation demanded from owners and problems of existing foundations, this paper proposes a new foundation, which is Sheet-Pile Foundation combining a footing with sheet-piles. A shallow foundation and Sheet-Pile foundation are modeled by frames supported with springs, which have relationships between subgrade reaction and displacement Laterally loaded foundation behaviors are compared by the model It is clear that laterally resistance of Sheet-Pile Foundation is larger than that of shallow foundation.

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Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (scientific journal)   Publisher：総合土木研究所  

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Language：Japanese   Publisher：埼玉大学地域共同研究センター  

DOI： 10.24561/00016677

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Publisher：The Japanese Geotechnical Society  

DOI： 10.11512/jiban.JGS38.0.1489.0

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Publisher：The Japanese Geotechnical Society  

DOI： 10.11512/jiban.JGS38.0.1487.0

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Publisher：The Japanese Geotechnical Society  

The authors developed the fiber reinforced liquefied stabilization soil, which consists of the liquefied stabilization soil, polypropylene bands, for a railway shield tunnel invert. he cyclic loading of railway acts on the surface of invert. Therefore modeled grounds consisted of the liquefied stabilization soil with polypropylene bands and without the bands are manufactured and cyclic loading tests are conducted in order to investigate the settlement behavior of the fiber reinforced liquefied stabilization soil.

DOI： 10.11512/jiban.JGS38.0.689.0

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Publisher：The Japanese Geotechnical Society  

DOI： 10.11512/jiban.JGS38.0.1597.0

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Language：English   Publisher：THOMAS TELFORD SERVICES LTD  

Web of Science

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Publisher：The Japanese Geotechnical Society  

DOI： 10.11512/jiban.JGS37.0.653.0

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Publisher：The Japanese Geotechnical Society  

DOI： 10.11512/jiban.jgs37.0.1917.0

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Language：Japanese  

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Event date： 2020.10 　 　

Language：English  

In Torrential Rain in Northern Kyushu region in Japan in July 2012, the foundation of a railway bridge across a small river settled approximately 0.3 m because of scouring. In this study, detailed investigations or tests, and simple repairs (jacking up of girders and track maintenance) were performed, and the slow-speed train service resumed approximately a month following the incident. Changes during this period in the reliability of the bridge bearing capacity were assessed by Bayesian updating with a particle filter.
The calculation results quantitatively indicated that the reliability index  decreased because of the damage and that the parameter value increased with more information, which revealed the validity of the engineering decisions during the damage restoration periods. It is expected that weather hazards will intensify in the future. Hence, the present findings can be used in the rapid recovery of structures that are subject to similar damage.

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Language：Japanese   Presentation type：Oral presentation (general)  

損傷抑制型杭頭結合方式は，復旧性を確保しながら杭頭結合部を積極的に塑性化させてエネルギー吸収を行う構
造形式である．これまで大型模型振動実験およびその再現解析に基づく検討が行われているが，これらでは模型
製作の都合上，固有振動数の違いによる共振特性の違い等が除外できていなかった．そこで本研究では，これら
の条件を仮想的に一致させた数値実験により杭頭部の塑性ヒンジ化の有無が地震時挙動に及ぼす影響について検
討した．その結果，杭地中部が塑性化しない限り杭頭部の塑性化が上部構造物の応答に悪影響を及ぼす可能性は
低く，地盤の固有周期によらず杭頭部の最大曲げモーメントの低減効果が期待できることが確認できた．

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Language：Japanese   Presentation type：Oral presentation (general)  

鉄道構造物の耐震設計では，一般的に梁ばね解析モデルを用いたプッシュオーバー解析と非線形応答スペクトル
法により実施されるが，実際の地震動は水平交番の繰返し作用であり，この作用の特性の差が基礎構造物の挙動
に及ぼす影響について検討事例した事例は少ない．
そこで本稿では，杭基礎に支持された鉄道橋脚を対象とし，静的な正負交番載荷を模擬した解析を実施すること
で，地震動の正負交番繰返し作用時における実橋脚基礎の挙動および残留変位について検討を行う．

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Language：Japanese   Presentation type：Oral presentation (general)  

損傷抑制型結合方式とは，復旧性を確保しながら杭頭結合部を積極的に塑性化させてエネルギー吸収を⾏う構造
形式である．この構造を用いた数値解析や実験から実構造物への適用に向けた検討が進められており，一般的な
構造解析モデルで地震時挙動を再現できることが確認されている．そこで本研究では，損傷抑制型結合方式の適
用拡大に向けて，杭径などのパラメーターを変更した試設計を行った．その結果，損傷抑制型結合方式を用いる
ことで一般的な設計と比較すると設計の難易度が上がるものの，杭体の鉄筋量を大幅に低減できるなど低コスト
化を図ることが可能であることを確認した．

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Language：Japanese   Presentation type：Oral presentation (general)  

スパイラル杭は、人力での施工が可能な杭で、狭隘な現場での適用が期待される。しかし、このような現場では
基礎自体を設置できる範囲が限られていることから杭を密に施工する必要があり、群杭効果を考慮する必要があ
る。そこで本研究では、スパイラル杭と円柱状の杭で水平載荷試験を実施し、結果を比較することでスパイラル
杭の群杭効果について検討した。
実験の結果、杭径の1％変位時の水平ばね定数で評価した結果に着目すると、円柱状の杭の方がスパイラル杭より
も群杭効果の値が大きい傾向があった。よって、スパイラル杭は載荷初期では通常の円柱状の杭よりも群杭効果
の影響が大きい可能性があることを設計の際に十分に考慮する必要がある。

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Language：Japanese   Presentation type：Oral presentation (general)  

自立式土留めの設計において，土留め壁の剛性と根入れ長とのバランスを合理的に設計することが求められ
る．著者らは地盤の破壊を簡易的に模擬できるアルミ棒積層体を用いて自立式土留め壁の剛性と根入れ長（壁
長）を主たるパラメータとした模型実験を行っており，本報文では掘削深さと水平変位の関係に着目し，特に相
対的に剛性が高く根入れが短い場合に実験結果が理論値とどのような関係にあるかを考察した．結果，剛性が高
い土留め壁はβL=1.2〜1.7程度を確保することで理論値で推定可能だと考えられ，また，実務で用いられる一般的
な目安（例えばβL≧2.5）はこれに対して安全側であることが確認できた．

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Language：Japanese   Presentation type：Oral presentation (general)  

「地盤工学会基準 杭の鉛直載荷試験方法・同解説 -第一回改訂版-」は，2002 年の改訂・刊行から18 年が経過
し，2018 年度より「杭の鉛直載荷試験基準改訂 WG」で改訂作業を進めている。本稿では，改訂 WG幹事会にお
いて検討した改訂案のうち，静的な載荷を対象とする「押込み試験方法」の載荷方法（載荷サイクル数と，段階
載荷か連続載荷か）を選定する考え方として，試験目的として押込み試験で得られる情報のうち何が含まれるか
を決定すれば，具体的な載荷方法が自動的に選定される考え方を示した。

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Language：Japanese   Presentation type：Oral presentation (general)  

スパイラル杭は人力による施工が可能な杭で、狭隘で重機使用が困難な現場での適用が期待される。しかし、こ
のような現場では基礎自体を設置できる範囲が限られており、杭を密に施工することとなるため、群杭効果を考
慮する必要がある。そこで本研究では、スパイラル杭の1列群杭模型での水平載荷試験を実施し、同様の実験を
行った円柱状のアクリル杭と結果を比較することでスパイラル杭の群杭効果について検討した。
実験の結果、スパイラル杭のほうが円柱状のアクリル杭よりも平均的に群杭効果の値が大きい傾向が
あった。よってスパイラル杭を用いる際、従来の円柱状の杭よりも杭間隔を密にしても効率よく水平抵抗を期待
できる可能性がある。

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Language：Japanese   Presentation type：Oral presentation (general)  

自立式土留め工法の設計では土留め壁の剛性と根入れ長とのバランスを合理的に決定することが求められる
が、剛性と根入れ長の両方をパラメータとして崩壊に至るまでの挙動を実験的（あるいは現場で実験的）に体系
化した検討事例は少ない。そこで本研究では、地盤の破壊を簡易的に模擬できるアルミ棒積層体を用いて自立式
土留め壁の剛性と根入れ長（壁長）を主たるパラメータとした模型実験を行い、これらが自立式土留め壁の崩壊
に対する安全性について検討した。結果、土留め壁の崩壊は、土留め壁の剛性により破壊モードに違いはあるも
のの、崩壊に至る掘削深さは剛性に依存しないことがわかった。

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Language：Japanese   Presentation type：Oral presentation (general)  

近接工事の掘削土留工事は，土留め壁の変形に伴い背面地盤に変形が生じるため，近接施工対策が必要とな
る．制限値が厳しい場合や離隔が確保できない場合は，新設側に加え既設側の対策も必要となる．既設側の対策
は①地盤強化・改良，②遮断防護工，③既設構造物の補強があり，①中の土留め壁背面の地盤改良は，特殊な施
工条件で用いられるものの施工実績も少なく，その効果を定量的に評価する実務的な設計手法が確立されていな
い．
本研究では，土留め壁背面を地盤改良する近接施工対策のうち，その地盤改良幅に着目し，砂地盤を模擬した
アルミ棒積層体を用いた二次元掘削模型実験により，地盤改良による土留め壁の変位抑制効果について検討し
た．

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：English   Presentation type：Oral presentation (general)  

This publication aims to describe the European and Japanese standards in order to discuss about the ongoing project of revision of the Japanese standard for static pile load tests, keeping in mind that the future version of this standard will have to take into accounts Japanese past experience, as well as the future needs to adapt to overseas practices, if necessary, for economical purposes. To do so, the different derived parameters that can be obtained by carrying out a static pile load test on a vertically loaded pile (instrumented or not) are described.
Then, the current practice for static pile load tests in Japan is described, and the main current overseas practices (with an extra focus on the European practices) are inventoried, and their differences (if any) with the Japanese practice are highlighted. Finally, these differences are discussed, and their importance assessed for a possible integration in the future Japanese standard, that could this way be seen for an oversea point of view as viable and legitimate alternative to the other and until now more common practices.

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Public lecture, seminar, tutorial, course, or other speech  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2017 　 　

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Event date： 2017 　 　

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Event date： 2015.8 　 　

Language：Japanese  

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Event date： 2014 　 　

Language：Japanese  

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Event date： 2014 　 　

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Event date： 2014 　 　

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Event date： 2014 　 　

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Event date： 2014 　 　

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2009.6 　 　

Language：English  

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Event date： 2007.2 　 　

Language：English  

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Event date： 2004.11 　 　

Language：English  

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Language：Japanese   Presentation type：Oral presentation (general)  

シートパイル基礎は,直接基礎のフーチング4辺にシートパイルを配置,結合した新しい基礎形式であり,地中に貫入,結合されたシートパイルの地盤拘束効果によるフーチング直下地盤の支持力向上と,地震時の基礎の転倒および滑動耐力増加が期待できる。本基礎は対象地盤が直接基礎の支持地盤としての条件を満たさない場合においても適用性があるとともに,施工性,経済性,環境調和性にも優れた基礎形式である。<br>本研究では,遠心模型振動実験によりシートパイル基礎の耐震性能について検討した。本報では以下に示す項目について検討した。<br>・ シートパイルの根入れ長の影響<br>・ シートパイルの耐力メカニズム

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Language：Japanese   Presentation type：Oral presentation (general)  

シートパイル基礎は,直接基礎のフーチング4辺にシートパイルを配置,結合した新しい基礎形式であり,地中に貫入,結合されたシートパイルの地盤拘束効果によるフーチング直下地盤の支持力向上と,地震時の基礎の転倒および滑動耐力増加が期待できる。本基礎は対象地盤が直接基礎の支持地盤としての条件を満たさない場合においても適用性があるとともに,施工性,経済性,環境調和性にも優れた基礎形式である。<br>本研究では,遠心模型振動実験によりシートパイル基礎の耐震性能について検討した。以下に検討項目を示す。<br>・シートパイル基礎と直接基礎の耐震性能と地震時挙動の比較<br>・シートパイルとフーチングの接合構造の影響

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Language：Japanese   Presentation type：Oral presentation (general)  

筆者らは直接基礎とその施工時の仮土留めに用いるシートパイルを組み合わせたシートパイル基礎を提案している。本研究では,その設計法を確立するため,模型実験を実施してその水平抵抗特性を把握し,その特性を適切に評価可能な設計モデルを提案することを目的としている。本論文は,シートパイル基礎の設計に用いる設計モデルを提案し,その提案モデルによる解析結果と「緩い砂地盤上のシートパイル基礎模型の水平載荷実験」で得られた模型実験の結果とを比較して,設計モデルの妥当性について検討した。その結果,提案モデルは簡易な骨組み解析モデルであっても高精度に荷重変位関係を評価できることが明らかとなった。

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Language：Japanese  

筆者らは直接基礎とその施工時の仮土留めに用いるシートパイルを組み合わせたシートパイル基礎を提案している。本研究では,その設計法を確立するため,模型実験を実施してその水平抵抗特性を把握し,その特性を適切に評価可能な設計モデルを提案することを目的としている。本論文は,平面ひずみ条件にて実施した模型実験の詳細について報告する。実験の結果,シートパイル基礎の直接基礎を上回る耐震性能,広い適用性を確認することができた。この結果を「シートパイル基礎の設計に用いる解析モデルの提案」にて,提案モデルの妥当性検証に用いる。

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Language：Japanese   Presentation type：Oral presentation (general)  

現行の磁気探査法では両コイル型磁気傾度計が用いられているが、鉄筋量の少ない場所打ち杭等では探査精度に問題があった。そこで筆者等は探査精度の向上と試験法の簡易化を図ることを目的に、新しいセンサー(ホール素子)を利用し、検証実験を実施した。本論文は、その結果を報告するものである。

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Language：Japanese  

筆者らは,直接基礎に鋼矢板を併用することで,支持力や変形性能を向上させたシートパイル基礎を提案している.その特徴としては,基礎寸法を縮小することによる低コスト化の他,狭隘区間での施工性向上,掘削発生土量の削減等が上げられる.本研究では,シートパイル基礎の基本的な支持力特性を把握するため,基礎平面寸法10cm&times;10cmの正方形模型と,平面ひずみ条件下での基礎幅10cmの長方形模型について,鉛直載荷試験を実施した.その結果,鋼矢板により支持力特性の向上が確認でき,また平面ひずみ条件での地盤挙動を画像解析システムを用いて観察し,その支持力向上メカニズムについて考察を行った.

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Language：Japanese   Presentation type：Oral presentation (general)  

回転圧入鋼管杭は、杭先端に螺旋状の羽根を設けた開端鋼管杭に、回転力を与えながら地盤に貫入・設置するもので、杭先端における羽根の拡底効果や回転圧入による地盤の締固め効果によって、押込みと引抜きの両方向の大きな支持力が得られることが期待されている。今回回転圧入鋼管杭を対象として、杭に作用する軸方向交番荷重に対する鉛直支持力特性、および引抜き抵抗力特性に関する資料を得ることを目的として、鉛直交番載荷試験を実施した。本報文ではその試験結果から動的な特性を検討した内容を簡単に紹介する。

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Language：Japanese   Presentation type：Oral presentation (general)  

回転圧入鋼管杭は、杭先端に螺旋状の羽根を設けた開端鋼管杭に、回転力を与えながら地盤に貫入・設置するもので、杭先端における羽根の拡底効果や回転圧入による地盤の締固め効果によって、押込みと引抜きの両方向の大きな支持力が得られることが期待されている。今回回転圧入鋼管杭を対象として、杭に作用する軸方向交番荷重に対する鉛直支持力特性、および引抜き抵抗力特性に関する資料を得ることを目的として、鉛直交番載荷試験を実施した。本報文ではその試験方法と、結果の概要を紹介する。

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Language：Japanese   Presentation type：Oral presentation (general)  

筆者らは鉄道シールドトンネルインバートに用いる流動化処理土として,PPバンド細片を混入した補強材混入流動化処理土の配合を定めた.鉄道シールドトンネルインバートに用いる流動化処理土には列車荷重による繰り返し荷重が作用する.そこで,通常の流動化処理土および補強材混入流動化処理土模型地盤を作製し,列車荷重相当の繰り返し載荷実験を行い,模型地盤の沈下特性を調べ,補強材混入流動化処理土の性能の確認を行った.

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2001.5 　 　

Language：Japanese  

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