K. Fujimoto, Y. Watanabe, Bastien Chevarier, J. Otani, Jun-ichi Hironaka
{"title":"EFFECT OF ANISOTROPY OF GEOGRID STIFFNESS ON LOAD TRANSFER MECHANISM OF PILE-GEOGRID COMBINED METHODS","authors":"K. Fujimoto, Y. Watanabe, Bastien Chevarier, J. Otani, Jun-ichi Hironaka","doi":"10.5030/JCIGSJOURNAL.25.65","DOIUrl":"https://doi.org/10.5030/JCIGSJOURNAL.25.65","url":null,"abstract":"The construction of embankment on soft ground often causes the differential settlement. A deep mixing method of soil stabilization and earth reinforcement technology using geogrid are used in order to reduce this settlement. It is usually considered that embankment load can be transferred with arching effect and membrane effect of geogrid. However, only the geogrid tensile stiffness in one direction of it orientation is considered for present design. The geogrid is a multidimensional structure and it is considered that a membrane effect is on not only one direction but also two or other direction depending on its orientation. The objective of this paper is to investigate the effect of anisotropy of geogrid stiffness on load transfer mechanism of pile-geogrid combined method using Discrete Element Method (DEM). As a conclusion, the load transfer mechanism depending on the geogrid orientation was clearly observed.","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127140242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akihiko Okamura, M. Kurata, Y. Kitamoto, Teruhiro Yoshida
{"title":"CONSTRUCTION OF A LATTICE-FRAME-REINFORCED SHEET ON THE SOFT GROUND","authors":"Akihiko Okamura, M. Kurata, Y. Kitamoto, Teruhiro Yoshida","doi":"10.5030/jcigsjournal.23.107","DOIUrl":"https://doi.org/10.5030/jcigsjournal.23.107","url":null,"abstract":"格子ジャケットを用いたシート工法は,筒状織物に流動性の高いモルタルを充填して格子状の補強枠を形成する表層安定処理工法で,格子構造が荷重分散効果を有し,軟弱地盤上に施工することで不同沈下の抑制が行える.これまでに水田上におけるトラフィカビリティーの改善実験や鉄道路床の試験施工,および河川護岸工事における短期間の仮設道路としての使用などの実績がある.本報告では深さ10m近くまでN値の低い地盤が堆積している軟弱地盤上に一般道路の仮設道路として施工した例を紹介すると共に,使用期間が1年以上と比較的長期にわたるため,追跡調査を行い施工後の状況について詳細調査を行った結果を報告する.","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"58 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121635235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"CENTRIFUGE TESTS ON SEISMIC STABILITY OF THE DAMAGED GEOGRID REINFORCED SOIL WALL","authors":"N. H. Giang, J. Kuwano, J. Izawa, S. Seki","doi":"10.5030/JCIGSJOURNAL.25.197","DOIUrl":"https://doi.org/10.5030/JCIGSJOURNAL.25.197","url":null,"abstract":"Recent huge earthquakes have caused severe and small damage to a number of geogrid-reinforced soil walls. For proper repair or reconstruction, it is necessary to evaluate degree of damage of those structures. In this research, the pullout test of geogrid subjected to the unloading-reloading process was carried out to learn its effects on the pullout resistance. The results were then used to evaluate the factor of safety and sliding surface of the damaged geogrid reinforced soil wall. GRSW models in centrifuge shaking and tilting table tests under 50G were performed. The damaged GRSW models were first achieved by both shaking and tilting. The damaged GRSW were then subjected to unloading-reloading process until the full collapse occurred. The pullout peak value and residual value using in current design of GRSW were also discussed.","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122718028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"DYNAMIC CENTRIFUGE MODEL TEST ON PILED GEO-WALL","authors":"T. Hara, S. Tsuji, A. Yashima, N. Tatta","doi":"10.5030/JCIGSJOURNAL.24.257","DOIUrl":"https://doi.org/10.5030/JCIGSJOURNAL.24.257","url":null,"abstract":"","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115377007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Hara, S. Shibuya, M. Saito, N. Torii, J. Chae, T. Masuo
{"title":"WATERTIGHT EMBANKMENT USING L-SHAPED GEOSYNTHETIC DRAIN","authors":"K. Hara, S. Shibuya, M. Saito, N. Torii, J. Chae, T. Masuo","doi":"10.5030/JCIGSJOURNAL.23.139","DOIUrl":"https://doi.org/10.5030/JCIGSJOURNAL.23.139","url":null,"abstract":"近年,豪雨による盛土構造物の変状や崩壊による災害が多発している.盛土背部や地山から浸透する雨水が盛土内に浸入することにより飽和領域が拡大し,サクションの低下により土の剛性および強度がともに減少することが原因と考えられる.したがって,この種の地盤災害軽減のためには,盛土内および周辺への雨水の浸入を許さないことが重要である.本研究では,盛土構造物を囲むようにジオシンセティックス排水材をL型に配置し,鉛直に設置した排水材で受けた浸透水を盛土底部に水平に設置した排水材に流すことにより盛土外へ速やかに排水させる方法を考案し,この手法による盛土防水効果を不飽和浸透流数値シミュレーションにより定量的に評価している.また,神戸市六甲山系で採取したまさ土を用いた模型実験結果と解析結果を詳細に比較検討することにより,提案する数値シミュレーション手法の工学的適用性を検証している.","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126816956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A few considerations of pullout test characteristics of geogrid reinforced sand using DEM analysis","authors":"Jun Zhang, N. Yasufuku, H. Ochiai","doi":"10.5030/JCIGSJOURNAL.22.103","DOIUrl":"https://doi.org/10.5030/JCIGSJOURNAL.22.103","url":null,"abstract":"Pullout tests are effective to investigate the interaction mechanism along the interface in geogrid reinforced zone. Micro scale geogrid-soil interactions are one of the fundamental important issues in pullout test response as well as actual field behavior of earth reinforcement. Hence, the discrete element analysis is carried out for pullout test from a micro point of view. The discrete element model is conducted to investigate the pullout response paying attention to compaction effect linked with porosity. The specimen is investigated in different porosities in order to evaluate the influence of degree of compaction on the strength, linked with the interface microscopic behavior. And the dilatancy predicted in the model may also provide useful information on the increase of the interface shear resistance.","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127722913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Soil-Geogrid Interaction Behavior under Wet Condition","authors":"Jun Zhang, N. Yasufuku","doi":"10.5030/JCIGSJOURNAL.23.31","DOIUrl":"https://doi.org/10.5030/JCIGSJOURNAL.23.31","url":null,"abstract":"Heavy rainfall is considered to be the main cause of the slope failures that cause collapse catastrophically without prior warning. Therefore in order to investigate the effect of rainfall on the stability of geogrid reinforced soil structures, this paper presents the result from a series of pullout tests for investigating interface behavior between soil and geogrid. By varying the water content of soil sample, the interaction behavior is determined by carrying out pullout tests in a displacement-rate controlled manner. The main test results obtained are presented, followed by discussion on the shear behavior of the soil-geogrid interface considering the effect of moisture content. It is shown that the normal stress level and interface water presence dominate the shear behavior of the soil-geogrid interface in the pullout tests.","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127515413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MECHANISM AND ESTIMATION OF TENSILE-REINFORCING EFFECTS IN THE DIRECT SHEAR TEST","authors":"K. Matsushima, Po-kai Wu, Y. Mohri, F. Tatsuoka","doi":"10.5030/JCIGSJOURNAL.23.15","DOIUrl":"https://doi.org/10.5030/JCIGSJOURNAL.23.15","url":null,"abstract":"土の一様なひずみに起因する補強材引張力は常に補強材面に沿った摩擦力が作用するが,不連続な変位に起因する補強材引張力は摩擦力だけでなく補強材面に垂直な力が土に作用する.直接せん断(DS)試験では土のひずみよりも不連続な変位に起因する引張り補強効果が強度発現の主因となるため,土の摩擦力との釣合いを基本とするせん断強度の推定式では試験結果をうまく説明できない.そこで,本研究では,不連続な変位場で表れる力の釣合いをモデル化したせん断強度の推定式を提案し,補強土のDS 試験結果と比較した.その結果,提案式では引張力の発達分布の違いによる補強効果の差を表現でき,せん断強度を適切に評価できることがわかった.","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"288 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123452959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Kawabata, Ayumu Kashiwagi, Y. Mohri, Satoshi Okuno
{"title":"Lateral loading model tests for buried pipe against thrust force backfilled with liquefied stabilized soil","authors":"T. Kawabata, Ayumu Kashiwagi, Y. Mohri, Satoshi Okuno","doi":"10.5030/JCIGSJOURNAL.24.171","DOIUrl":"https://doi.org/10.5030/JCIGSJOURNAL.24.171","url":null,"abstract":"近年,埋設パイプライン施工時の埋戻しに際して,流動化処理土を用いる事例が増加している.本論では,スラスト力が作用する曲管部の受働側地盤における埋戻し材に流動化処理土を使用するとともに,その中に補強材を敷設することにより,受働抵抗力増加を図る新たなスラスト防護工法を提案し,口径260mmの模型パイプを使用した水平載荷模型実験を実施した.計測項目は,パイプに作用する水平荷重,パイプの水平変位である.実験結果より,補強材が,流動化処理土の有する脆性的な性質を改善し,受働抵抗力増加に寄与することがわかった.また,補強材の種類が受働抵抗力の増減に影響を与えることが明らかとなった.","PeriodicalId":165094,"journal":{"name":"Jioshinsetikkusu Rombunshu (geosynthetics Engineering Journal)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128284864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}