{"created":"2021-03-01T06:51:33.505279+00:00","id":32841,"links":{},"metadata":{"_buckets":{"deposit":"b5d303ec-35a5-4b34-a69f-d2fc07913341"},"_deposit":{"id":"32841","owner":"1","owners":[],"pid":{"revision_id":0,"type":"depid","value":"32841"},"status":"published"},"_oai":{"id":"oai:repository.dl.itc.u-tokyo.ac.jp:00032841","sets":["80:4535:4757:4758","9:504:4538:4759:4760"]},"author_link":["127978","127979","127976","127977"],"item_4_alternative_title_1":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"A Granular Assembly Simulation for the Liquefaction of Sand and Quick Sand"}]},"item_4_biblio_info_7":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"1988-03-31","bibliographicIssueDateType":"Issued"},"bibliographicIssueNumber":"4","bibliographicPageEnd":"577","bibliographicPageStart":"535","bibliographicVolumeNumber":"62","bibliographic_titles":[{"bibliographic_title":"東京大學地震研究所彙報 = Bulletin of the Earthquake Research Institute, University of Tokyo"}]}]},"item_4_description_13":{"attribute_name":"フォーマット","attribute_value_mlt":[{"subitem_description":"application/pdf","subitem_description_type":"Other"}]},"item_4_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"土とか岩は,砂粒とか土粒子でできていたり,多くの割れ目があったりで,本質的には連続体ではない.勿論,通常の問題では,大変形が生じる訳ではないので,連続体としての解析で何ら支障はないのであるが,土砂崩壊とか液状化とか,大変形時には無理がある.非連続体の解析手法としては,現在までのところ,有限要素法に滑り要素を導入したものや,有限要素法を多少変えた川井のRBSM法(Rigid Body Spring Method),CundallのDEM法(Distinct Element Method)がある.どの手法にも一長一短があるが,有限要素法の流れを汲む前二者では,要素の辺に沿って滑る変形しかできないし,隣り合う要素と要素が離れてしまうなどということもできない.それは,要素の格子点は,隣り合う多くの要素に共有されているので,要素と要素が離れてしまい,今まで1つであった格子点が複数にならなければならないが,それが,全く不可能ではないにせよ,かなり面倒なのである.ところが,実際の現象では,岩石の崩壊の際には,岩塊と岩塊は離れるばかりでなく空中を飛ぶことだってある.一方CundallのDEM法は,要素は元々,バラバラのものとしての取り扱いである.そのバラバラの独立した要素一つ一つについて運動方程式をたてる.したがって,岩石が崩壊する時,岩塊同志が衝突したり,跳んだり,転がったりすることも可能である.現在まで,このDEM法による粒状体シミューショシは,粒体間の間隙に水が飽和している場合については,殆んど行われていなかったので,筆者らは,二次元粒体に水圧を考慮する事によって,地震時の砂の液状化と,大雨の場合の間隙水圧上昇によるQuick Sand現象をこの粒状体シミュレーションで解析することを試みた.そして,或る程度の成功を得た.しかしながら,粒径が砂のように小さくなり,間隙水の体積弾性率の大きい影響で,P波の伝播速度が大きくなり,その結果,計算の安定のため,計算時間刻みを100万分の1秒のように小さくとらねばならず,解析粒数を200個強しかとれなかった.実際の液状化を詳細に模擬するには,3次元解析か必要であり,これは,将来の計算機の高速化をまたねばならない.","subitem_description_type":"Abstract"},{"subitem_description":"Various kinds of liquefaction analysis have been carried out in laboratory experiments and using the Finite Element Method (FEM). But, no numerical liquefaction analysis in which sand has been considered a non continuous material has yet been reported. In 1971, the Distinct Element Method (DEM) was introduced by Cundall; a numerical simulation used to analize the behavior of rock, based on the assumption that each individual rock element satisfies the equation of motion. We have developed a modified DEM using Darcy's law that takes into account the pore water pressure. We analyzed the liquefaction of saturated sand under seismic excitation and also the quick sand phenomenon due to water pressure. The assembly model consists of circular elements with log-normal distributed radii, and it is packed by dropping. We used the nonlinear spring in the normal direction between particles in order to express the \"\"Dilatancy\"\" in two dimensional treatment. The excessive pore pressure of the numerical result rose gradually due to the shaking effect. This result agreed with the results of the past laboratory tests. However, the contact of the neighboring particles was not easy to hide even under the high pore pressure, and resultantly, a complete liquefaction phenomenon could not be realized. The complete liquefaction can be analyzed only by the three dimensional analysis or a forced strain input. However, it needs much more computing time, and we have to wait for an advanced and faster computors. We also made the quick sand phenomenon occurr in the model assembly by applying the uplifting water pressure at the bottom of the assembly. A time history of the excessive pore water peressure was also obtained at the point near the bottom or the surface of the assembly.","subitem_description_type":"Abstract"}]},"item_4_full_name_3":{"attribute_name":"著者別名","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"127978","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Tarumi, Yuji"}]},{"nameIdentifiers":[{"nameIdentifier":"127979","nameIdentifierScheme":"WEKO"}],"names":[{"name":"Hakuno, Motohiko"}]}]},"item_4_identifier_registration":{"attribute_name":"ID登録","attribute_value_mlt":[{"subitem_identifier_reg_text":"10.15083/0000032841","subitem_identifier_reg_type":"JaLC"}]},"item_4_publisher_20":{"attribute_name":"出版者","attribute_value_mlt":[{"subitem_publisher":"東京大学地震研究所"}]},"item_4_source_id_10":{"attribute_name":"書誌レコードID","attribute_value_mlt":[{"subitem_source_identifier":"AN00162258","subitem_source_identifier_type":"NCID"}]},"item_4_source_id_8":{"attribute_name":"ISSN","attribute_value_mlt":[{"subitem_source_identifier":"00408972","subitem_source_identifier_type":"ISSN"}]},"item_4_subject_15":{"attribute_name":"日本十進分類法","attribute_value_mlt":[{"subitem_subject":"453","subitem_subject_scheme":"NDC"}]},"item_4_text_21":{"attribute_name":"出版者別名","attribute_value_mlt":[{"subitem_text_value":"Earthquake Research Institute, University of Tokyo"}]},"item_4_text_4":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_value":"日本道路公団"},{"subitem_text_value":"東京大学地震研究所"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"垂水, 祐二"}],"nameIdentifiers":[{"nameIdentifier":"127976","nameIdentifierScheme":"WEKO"}]},{"creatorNames":[{"creatorName":"伯野, 元彦"}],"nameIdentifiers":[{"nameIdentifier":"127977","nameIdentifierScheme":"WEKO"}]}]},"item_files":{"attribute_name":"ファイル情報","attribute_type":"file","attribute_value_mlt":[{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2017-06-26"}],"displaytype":"detail","filename":"ji0624011.pdf","filesize":[{"value":"2.1 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"ji0624011.pdf","url":"https://repository.dl.itc.u-tokyo.ac.jp/record/32841/files/ji0624011.pdf"},"version_id":"2c7721a8-dea0-4e6f-a58d-7fa875f9a153"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"jpn"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"departmental bulletin paper","resourceuri":"http://purl.org/coar/resource_type/c_6501"}]},"item_title":"Quick Sandと液状化に関する粒状体シミュレーション","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"Quick Sandと液状化に関する粒状体シミュレーション","subitem_title_language":"ja"}]},"item_type_id":"4","owner":"1","path":["4758","4760"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2008-05-30"},"publish_date":"2008-05-30","publish_status":"0","recid":"32841","relation_version_is_last":true,"title":["Quick Sandと液状化に関する粒状体シミュレーション"],"weko_creator_id":"1","weko_shared_id":-1},"updated":"2022-12-19T04:09:36.883016+00:00"}