{"created":"2023-06-20T15:09:36.998010+00:00","id":5593,"links":{},"metadata":{"_buckets":{"deposit":"f2170aaf-f414-4d91-8741-b79d24330e34"},"_deposit":{"created_by":17,"id":"5593","owners":[17],"pid":{"revision_id":0,"type":"depid","value":"5593"},"status":"published"},"_oai":{"id":"oai:ynu.repo.nii.ac.jp:00005593","sets":["553:556"]},"author_link":["27696","27695"],"item_7_alternative_title_21":{"attribute_name":"その他のタイトル","attribute_value_mlt":[{"subitem_alternative_title":"実験で観察された津波越流時の防波堤マウンドの洗掘挙動に関するSPHシミュレーション","subitem_alternative_title_language":"ja"}]},"item_7_biblio_info_8":{"attribute_name":"書誌情報","attribute_value_mlt":[{"bibliographicIssueDates":{"bibliographicIssueDate":"2014-09-25","bibliographicIssueDateType":"Issued"}}]},"item_7_date_granted_66":{"attribute_name":"学位授与年月日","attribute_value_mlt":[{"subitem_dategranted":"2014-09-25"}]},"item_7_degree_grantor_64":{"attribute_name":"学位授与機関","attribute_value_mlt":[{"subitem_degreegrantor":[{"subitem_degreegrantor_name":"横浜国立大学"}],"subitem_degreegrantor_identifier":[{"subitem_degreegrantor_identifier_name":"12701","subitem_degreegrantor_identifier_scheme":"kakenhi"}]}]},"item_7_degree_name_63":{"attribute_name":"学位名","attribute_value_mlt":[{"subitem_degreename":"博士(工学)"}]},"item_7_description_5":{"attribute_name":"抄録","attribute_value_mlt":[{"subitem_description":"Failure of a breakwater during tsunami causes extensive damages to the human lives and properties. Therefore it is very important to investigate the failure mechanisms of a breakwater due to tsunami. Many studies were conducted to investigate the failure mechanisms of a breakwater but a few concentrated extensively on scour of landside mound. The study has attempted to investigate the failure mechanism of a breakwater focusing on the deformation behavior of mound due to scour with experimentally as well as numerically. Moreover, it has proposed some counter measures and has also observed the changes of deformation behavior of the mound due to introduction of the countermeasures.For experimental investigation, the study has prepared a model of Kamaishi breakwater with a scale of 1/200 of the prototype. Overtopping tsunami water falling into the landside mound with seepage flow due to head difference between landside and seaside of the breakwater was prepared in the experiment to reproduce the natural tsunami attack in caisson type breakwater system. To explore the scour mechanisms the study has conducted experiments with several cases. The cases were designed to observe only seepage flow effect on scour, only overtopping water effect on scour and finally combination of seepage and overtopping effect on scour. The study has found that scour due to overtopping water in the mound increased when seepage flow was combined together. The experimental study has found that existence of hydraulic gradients between seaside and landside of the breakwater was a key parameter to accelerate the scour depth. It has also found that mound showed simultaneous scour and collapse behavior during the process of scouring. Therefore, countermeasures were designed with an ability to reduce the hydraulic gradients and also to control the collapse of mound. It was found that maximum hydraulic gradient was reduced from 0.44 to 0.30 with the introduction of the countermeasures. Collapse of mound was found to be controlled due to physical reinforcement effect. Moreover, it was found that countermeasure had changed the transportation characteristics of the scoured soils. As a result the scour depth and width were found to be significantly reduced when countermeasures were installed in the experiment.The study has also attempted to simulate numerically the deformation behavior of mound due to scour. For numerical simulation it has developed a smoothed particle hydrodynamic (SPH) code with capability of simulating water and soil together. Water was developed as a Newtonian fluid with viscosity and soil was developed as an elastic perfectly plastic material with Drucker-Prager failure criteria. The study has conducted simulation of couette flow, shear cavity flow, dam break flow to prove the accuracy of the developed SPH code for fluid. Moreover, simple shear test for soil, granular flow test and bearing capacity test for soil were conducted to validate the SPH code for soil. Additionally, flow of water through the porous soil was simulated to verify the coupling ability of the code. It was found that SPH codes for fluid, soil and water-soil coupling were successful in simulating the benchmark cases.The developed SPH code has used a simplified scour model based on seepage force to take into account the high impact force due to fall of overtopping water as well as the seepage flow from the seaside. The study has simulated the deformation behavior of mound during scour for the same cases as conducted in the experiment. Scour results from the simulations for all the cases with and without countermeasure were found to follow the same trend as that in the experiment.It was found from both experiment and numerical simulations that deformation behavior due to scour during tsunami overtopping were influenced by the head difference between seaside and landside of the breakwater.","subitem_description_type":"Abstract"}]},"item_7_dissertation_number_67":{"attribute_name":"学位授与番号","attribute_value_mlt":[{"subitem_dissertationnumber":"甲第3号"}]},"item_7_full_name_2":{"attribute_name":"著者(ヨミ)","attribute_value_mlt":[{"nameIdentifiers":[{"nameIdentifier":"27696","nameIdentifierScheme":"WEKO"}],"names":[{"name":"ｲｽﾗﾑ, ﾓﾊﾒﾄﾞ ﾙｾﾄﾞｩﾙ"}]}]},"item_7_subject_24":{"attribute_name":"国立国会図書館分類","attribute_value_mlt":[{"subitem_subject":"UT51","subitem_subject_scheme":"NDLC"}]},"item_7_text_4":{"attribute_name":"著者所属","attribute_value_mlt":[{"subitem_text_value":"Graduate School of Urban Innovation, Yokohama National University"}]},"item_7_text_65":{"attribute_name":"学位授与年度","attribute_value_mlt":[{"subitem_text_value":"2014年度"}]},"item_7_version_type_18":{"attribute_name":"著者版フラグ","attribute_value_mlt":[{"subitem_version_resource":"http://purl.org/coar/version/c_970fb48d4fbd8a85","subitem_version_type":"VoR"}]},"item_access_right":{"attribute_name":"アクセス権","attribute_value_mlt":[{"subitem_access_right":"open access","subitem_access_right_uri":"http://purl.org/coar/access_right/c_abf2"}]},"item_creator":{"attribute_name":"著者","attribute_type":"creator","attribute_value_mlt":[{"creatorNames":[{"creatorName":"Islam, Mohammed Russedul","creatorNameLang":"en"}],"nameIdentifiers":[{"nameIdentifier":"27695","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":"2016-09-20"}],"displaytype":"detail","filename":"mohammed_russedul_islam-abstract.pdf","filesize":[{"value":"77.0 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"mohammed_russedul_islam-abstract.pdf","url":"https://ynu.repo.nii.ac.jp/record/5593/files/mohammed_russedul_islam-abstract.pdf"},"version_id":"51c940f4-acfb-4fd4-a7c4-f9e69adb0652"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2016-09-20"}],"displaytype":"detail","filename":"mohammed_russedul_islam-review.pdf","filesize":[{"value":"466.3 kB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"mohammed_russedul_islam-review.pdf","url":"https://ynu.repo.nii.ac.jp/record/5593/files/mohammed_russedul_islam-review.pdf"},"version_id":"3620887c-2495-4763-8bf4-dc5446db2ef0"},{"accessrole":"open_date","date":[{"dateType":"Available","dateValue":"2016-09-20"}],"displaytype":"detail","filename":"mohammed_russedul_islam-thesis.pdf","filesize":[{"value":"12.1 MB"}],"format":"application/pdf","licensetype":"license_note","mimetype":"application/pdf","url":{"label":"mohammed_russedul_islam-thesis.pdf","objectType":"fulltext","url":"https://ynu.repo.nii.ac.jp/record/5593/files/mohammed_russedul_islam-thesis.pdf"},"version_id":"54f570f7-4597-4150-884f-3cc4d778603a"}]},"item_language":{"attribute_name":"言語","attribute_value_mlt":[{"subitem_language":"eng"}]},"item_resource_type":{"attribute_name":"資源タイプ","attribute_value_mlt":[{"resourcetype":"doctoral thesis","resourceuri":"http://purl.org/coar/resource_type/c_db06"}]},"item_title":"SPH simulations on failure of a breakwater mound due to tsunami scour under experimental conditions","item_titles":{"attribute_name":"タイトル","attribute_value_mlt":[{"subitem_title":"SPH simulations on failure of a breakwater mound due to tsunami scour under experimental conditions","subitem_title_language":"en"}]},"item_type_id":"7","owner":"17","path":["556"],"pubdate":{"attribute_name":"PubDate","attribute_value":"2014-12-26"},"publish_date":"2014-12-26","publish_status":"0","recid":"5593","relation_version_is_last":true,"title":["SPH simulations on failure of a breakwater mound due to tsunami scour under experimental conditions"],"weko_creator_id":"17","weko_shared_id":-1},"updated":"2024-03-08T01:25:09.961928+00:00"}