著者

Mahtab Alitalesh Mostafa Mollaali Mahmoud Yazdani

出版者

The Japanese Geotechnical Society

雑誌

Japanese Geotechnical Society Special Publication (ISSN:21888027)

巻号頁・発行日

vol.2, no.12, pp.504-507, 2016-01-31 (Released:2016-01-29)

参考文献数

36

被引用文献数

7

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Determination of rock engineering properties is important in civil, mining and geotechnical engineering. Uniaxial Compressive Strength (UCS) is one of the most important properties of rocks. Point Load Test (PLT) is practically used in geotechnical engineering to determine rock strength index. Despite that the PLT is fast, economical and simple in either field or laboratory, Uniaxial Compressive Test (UCT) is time-consuming and expensive. UCS can be estimated using Point Load Index (PLI). So, implementation of correlation between results of PLT and UCT is of interest. In this research correlation between the results of point load test and uniaxial compressive test are presented for rock samples from three sites in Iran. Two rock types including Shale and Marlstone have been utilized in this research. Correlations between UCS and PLI in this study are verified with proposed equation by pervious researchers.

著者

Takayuki Shimaoka Koji Kumagai Takeshi Katsumi Michio Iba

出版者

The Japanese Geotechnical Society

雑誌

Japanese Geotechnical Society Special Publication (ISSN:21888027)

巻号頁・発行日

vol.2, no.70, pp.2385-2390, 2016-01-31 (Released:2016-01-29)

参考文献数

5

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A number of temporary storage sites have been commissioned to contain soils and wastes generated from the decontamination works after the accident at Tokyo Electric Power Company’s Fukushima Dai-ichi Nuclear Power Plant. At these sites, volume reduction has been observed in the flexible container bags caused by the dehydration and decomposition of the decontamination waste inside. This situation leads to uneven settlement of the top of these flexible container bags in these temporary storage sites, and might result in problems such as leakage through top and bottom liners installed to contain these container bags. To deal with these problems immediately, the Geomembrane Technical Committee, Japan Chapter of International Geosynthetics Society has conducted deliberations and made reports on procedures for selection and installation of storage containers that are to prevent polluted water from leaking outside of storage sites, structures, and barrier materials, a new inspection procedure for seaming of cover geomembranes, installation of cover materials that are to counter uneven settlement of soil, and also temperature control procedures to prevent natural ignition of waste. This paper summarizes the deliberations and the procedures adopted.

著者

三村 衛 吉村 貢 寺尾 庸孝 豊田 富士人 中井 正幸

出版者

The Japanese Geotechnical Society

雑誌

地盤工学ジャーナル (ISSN:18806341)

巻号頁・発行日

vol.6, no.2, pp.141-155, 2011

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岐阜県最大の前方後円墳である昼飯大塚(ひるいおおつか)古墳の史跡整備の一環として実施された発掘調査に伴い,地盤工学の観点から墳丘盛土の調査を行った。破壊的な調査・試験方法が適用できないことから,本質非破壊調査手法である表面型RI密度水分計と針貫入試験を適用した。針貫入試験による力学的な特徴から墳丘盛土がほぼ水平の構造を持つことが明らかとなった。部分的には斜めの層構造も確認され,古墳墳丘の築造材料の掘削・運搬・荷降ろしの過程を考察する資料を得た。また,強度の変動パターンを分析することにより,墳丘盛土が15~40cm程度の層厚で築造されたという痕跡が得られ,墳丘試料に対する締固め試験により,墳丘盛土の築造時の締固めエネルギーは,およそ人が足で踏み固めたものに相当する0.1×E_cJIS程度であることがわかった。墳丘復元に使用される候補材料についても室内地盤材料試験を行って,現墳丘の性状に近い材料を選定し,墳丘復元工事の施工方法を提案した。

著者

大木 基裕 中野 正樹 酒井 崇之 関 雅樹

出版者

The Japanese Geotechnical Society

雑誌

地盤工学ジャーナル (ISSN:18806341)

巻号頁・発行日

vol.9, no.1, pp.59-70, 2014

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鉄道構造物の中でも既設盛土の耐震補強化は喫緊の課題であり,大規模崩壊の恐れのある盛土の耐震補強が行われている。本稿では,現行の鉄道技術基準に基づく盛土の耐震性能の考え方とこれまでの耐震補強の概要を示す。次に,3つの粘土地盤上の盛土を対象に,動的遠心模型実験,有限要素解析を実施し,地震時における盛土の破壊形態を確認し,ニューマーク法による変形予測の精度を検証する。実験や解析の結果,同一の支持地盤の強度であれば盛土が高くなるほど,また,同一の盛土高さであれば支持地盤の強度が小さくなるほど,破壊形態は,盛土主体から地盤も含む破壊形態へと移行し,変形レベルも大きくなる。また,盛土を主体とする円弧すべり状の破壊形態が生じたケースに対しニューマーク法を用いた結果,求められた沈下量は模型実験結果とほぼ等しくなった。簡便な耐震性能評価手法であるニューマーク法は,盛土の破壊形態を適切に考慮することにより沈下量の精度は高まり,設計において有用となることが示唆された。

著者

ハザリカ へマンタ 片岡 俊一 笠間 清伸 金子 賢治 末次 大輔

出版者

The Japanese Geotechnical Society

雑誌

地盤工学ジャーナル (ISSN:18806341)

巻号頁・発行日

vol.7, no.1, pp.13-23, 2012

被引用文献数

8

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東北地方太平洋沖地震は,その地震動および津波によって東日本の広範囲で甚大な被害をもたらした。本論文は,青森県三八上北地方および岩手県北部において発生した地盤災害に対しての調査結果をまとめたものである. 調査地域の範囲内では地震そのものより複合性のある被害(例:津波による地盤災害や液状化による被害など)が顕著であった. 本論文では, 特に地震動, 押し波, 引き波および構造物の構造形式などを着眼とした太平洋沿岸部の被害について述べる.

著者

三村 衛 吉村 貢 寺尾 庸孝 豊田 富士人 中井 正幸

出版者

The Japanese Geotechnical Society

雑誌

地盤工学ジャーナル (ISSN:18806341)

巻号頁・発行日

vol.6, no.2, 2011

著者

Keiichiro Shibata Hidenori Yoshida Naomichi Matsumoto

出版者

The Japanese Geotechnical Society

雑誌

Japanese Geotechnical Society Special Publication (ISSN:21888027)

巻号頁・発行日

vol.1, no.4, pp.7-10, 2015-08-30 (Released:2015-08-31)

参考文献数

8

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The serious nuclear disaster in the Fukushima Daiichi nuclear energy plant of the Tokyo Electricity Power Company was occurred by the tsunami which was caused by the Great East Japan Earthquake on March 11, 2011. The radioactive materials emitted by the disaster were widely diffused in and around Fukushima prefecture including the Pacific Ocean by wind, rain and a flow of river. It can’t be always said that there is no risk of the condensation of radioactive materials in human’s body by ecological chain if fish take in radiation in the ocean contaminated by the radioactive materials. However the effective decontamination methods of the radioactive materials are not developed and the decontamination is less-advanced. The establishment of a new decontamination method is urgent need and indispensable in light of disadvantageous effect on ecological system. Thus, in this study, it is aimed to establish a new decontamination technology of radioactive materials deposited on seabed or lake bed. In particular, the new adsorption material which can adsorb radioactive materials is developed and the new method which can move them from the bottom sediment is proposed. The results obtained from various tests with or without the water circulation and the adsorption material indicate that the water circulation is effective and that the adsorption material has a great deal of potential in the decontamination of radioactive materials. It is expected that the proposed method and the developed adsorption material are efficient to remove radioactive materials from seabed or lake bed when they are expansively applied to the real decontamination.

著者

後藤 聰 龍岡 文夫 澁谷 啓 金 有性 佐藤 剛司

出版者

The Japanese Geotechnical Society

雑誌

土質工学会論文報告集 (ISSN:03851621)

巻号頁・発行日

vol.31, no.1, pp.169-180, 1991-03-15 (Released:2008-02-29)

参考文献数

16

被引用文献数

187 304

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A simple device named "local deformation transducer(LDT)" was developed to investigate stiffness of soils that can be measured in the laboratory for strain levels ranging from 10-6 to 10-2. The theoretical consideration into the non-linear, but uniquely determined, relationship between the gauge strain (i.e., output voltage) and the axial strain is first described. The accuracy of the strain measurement using LDT is then discussed based on the theory and the results of calibration tests. The stability of the output voltage was examined for a few days using a dummy. In isotropic consolidation tests performed on a fine clean sand in triaxial cells, the internal axial strains measured using LDT agreed well with those associated with the condition of no bedding error, which were extrapolated from the results of tests using the specimens with various heights. Besides, in plane strain compression, the internal axial strain measured using the LDT was close to that determined by means of a laser speckle method. The capability of the LDT has been demonstrated in triaxial tests in which the variations of Young's modulus of a gravel, a cement-treated sandy soil and a soft rock were successfully measured for the prescribed range of strains as the specimens were subjected to both monotonic and cyclic loadings.

著者

浅岡 顕 松尾 稔

出版者

The Japanese Geotechnical Society

雑誌

土質工学会論文報告集 (ISSN:03851621)

巻号頁・発行日

vol.20, no.4, pp.53-66, 1980-12-15 (Released:2008-02-29)

参考文献数

5

被引用文献数

8 16

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This paper intends to give theoretical bases for observational settlement prediction methods which use autoregressive equations. The master differential equation derived is demonstrated to be effective even for a multilayered soil system under gradual load application. The technique for parameter identification of higher order autoregressive equations is also provided and numerical simulations show high applicability of the proposed method.

著者

Kenichi Sato Takuro Fujikawa

出版者

The Japanese Geotechnical Society

雑誌

Japanese Geotechnical Society Special Publication (ISSN:21888027)

巻号頁・発行日

vol.3, no.2, pp.65-70, 2015-09-30 (Released:2016-05-28)

参考文献数

3

被引用文献数

1 5

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The recent increase in the generation and use of coal fly ash by electric power stations and various industries has contributed to Japan developing technology to facilitate the utilization of fly ash as ground material, including the use of fly ash for fills and embankments, pavement and subbase courses, subgrade stabilizations, landfill cover, soil improvement, land reclamation, slurried flowable ash and water pollution control. This paper describes the state of the art related to coal fly ash utilization as geo-material in Japan. In particular, this paper describes the material properties and technology associated with each technique. As coal fly ash contains a very small amount of heavy metal which should be considered for geo-environmental safety, this paper also discusses quality and inspection techniques for coal fly ash materials.

著者

小嶋 正樹 杉井 俊夫 八嶋 厚 沢田 和秀 森口 周二

出版者

The Japanese Geotechnical Society

雑誌

地盤工学ジャーナル (ISSN:18806341)

巻号頁・発行日

vol.1, no.3, pp.33-43, 2006

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道路防災点検によって抽出された早急に対策を要する膨大な数の危険斜面の中から, 優先的に対策を施すべき危険斜面を選定するための手法として, すべての危険斜面に対して対策の優先順位をつけるロジットモデル解析を提案する。岐阜県内の特定の地域を対象に, 防災専門家による点検結果の所見に含まれるキーワードから, これまでに優先的に対策が施された危険斜面の選定に大きな影響を及ぼしたと考えられるキーワードを抽出し, そのキーワードを基準要因とする要因モデルを構築した。構築した要因モデルを岐阜県内の他の地域に適用して対策の有無の的中率を算出し, 本解析手法の妥当性を検証した。また, 本解析手法をシステム化するにあたり道路防災点検結果をデータベース化し, 解析・データ管理する基盤として道路防災GISを構築した。

著者

Hemanta Hazarika Amizatulhani Abdullah

出版者

The Japanese Geotechnical Society

雑誌

Japanese Geotechnical Society Special Publication (ISSN:21888027)

巻号頁・発行日

vol.2, no.68, pp.2336-2341, 2016-01-31 (Released:2016-01-29)

参考文献数

14

被引用文献数

6

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This study focuses on accumulation of basic data on deformation and energy absorbing characteristics of geosynthetics (recycled tire chips and geogrid), which are used as liquefaction prevention materials for shallow foundations. Because tire chips have high compressibility, decrease of bearing capacity and excessive differential settlement of the foundation ground may arise. A new reinforcement method, using gravel mixed tire chips layer and layers of geogrid, was proposed to compensate for the inadequate bearing capacity and suppress differential settlement. In this study, the deformation and energy absorbing characteristics of tire chips and gravel mixed tire chips were made clear by performing direct shear test under dynamic loading using a large scale shearing device. Based on the results, it was found that the vibration-absorbing energy of tire chips decreases as the gravel fraction increases. Considering the pros and cons, we could arrive at the conclusion that the sample with 50% gravel mixture was the most effective. It was also confirmed that the rigidity of gravel mixed tire chips was improved through reinforcement by geogrid.

著者

嘉門 雅史 張 虎元 勝見 武 澤 直樹

出版者

The Japanese Geotechnical Society

雑誌

地盤工学会論文報告集 (ISSN:13417452)

巻号頁・発行日

vol.42, no.6, pp.79-91, 2002-12-15 (Released:2008-02-29)

参考文献数

37

被引用文献数

1 12

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Microbial activities can be enhanced by organic rich leachate occurring in solid waste landfills, which possesses the potential to alter the barrier capacity of clay liners. Flexible-wall hydraulic conductivity tests are conducted to investigate the effect of the microbial activities on the hydraulic conductivity of Osaka marine clay used for clay liners of offshore solid waste landfill sites in Japan. Permeants with different redox potentials are employed to investigate the redox effect; and, permeants with high nutrients are used to check the effect of the microbial production in soil specimens. Test results indicate that there are no obvious changes in the free swell index, the liquid limit, or the hydraulic conductivity of the marine clay when a strong reducing agent is used. When nutrients are applied for the growth of microorganisms, however, a decrease in hydraulic conductivity, ranging from greater than two orders of magnitude to less than one order of magnitude, is observed. The formation of biofilm and anaerobic inorganic precipitation on the surface of the soil particles is considered to be responsible for this reduction in hydraulic conductivity. Test results reveal that microbial activities, enhanced by landfill leachate, may not cause an increase in the hydraulic conductivity of natural clay liners of offshore landfill sites.

著者

栖原 秀郎 新井 洋一 中越 健太 赤神 元英 黒山 英伸

出版者

The Japanese Geotechnical Society

雑誌

地盤工学ジャーナル (ISSN:18806341)

巻号頁・発行日

vol.6, no.2, pp.317-329, 2011

被引用文献数

1

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近年,工場跡地等の再開発に伴う土壌汚染が社会的問題となっていることから,汚染状況の把握,健康被害防止の措置などを定めて土壌汚染対策を実施することを目的に,平成15年2月より土壌汚染対策法(平成14年法律第53号)が施行され, 平成22年4月には改正土壌汚染対策法が施行された。一方,法規制外においても,土地取引等に対し自主調査・自主対策が行なわれ,むしろこちらの方が実施は多い。本文では,このような背景の下,繊維会社工場跡地における,第一種特定有害物質である揮発性有機化合物による大規模土壌・地下水汚染に対し,オンサイトにおいて,短期間で浄化した自主対策事例を紹介する。本事例では,回転式破砕・拡散混合工法による石灰混合処理を核にした方法により,揮発性有機化合物の土壌汚染では,環境基準の77倍,地下水汚染では環境基準の4,000倍までの汚染の浄化が可能であることを確認できた。