著者

原田 英治 五十里 洋行 後藤 仁志 菅原 康之 松藤 慶之

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.71, no.2, pp.I_487-I_492, 2015 (Released:2015-11-10)

参考文献数

16

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波打ち帯での遡上波の打上げと打下げの相互干渉は,砕波を伴う複雑な自由水面の変化をもたらす.また,透水性を有した斜面での浸透・滲出流の存在は,底面掃流力に影響するが,ドライベッドへの打上げは底面掃流力の急変をもたらすため,漂砂量の見積に大きな影響をおよぼす.本研究では,複雑な水表面境界と移動床境界を追跡するため,波動場計算にMPS法を採用し,移動床計算にDEMを用いたMPS-DEMカップリングによる数値シミュレーションを実施する.計算で得られた礫浜斜面における浸透・滲出流による圧力勾配力の位相別岸沖分布から,海浜変形計算に対する浸透流の重要性が示された.また,特に掃流力が強く,顕著な浸透流が見込まれる領域では,浸透流を考慮した漂砂量予測の重要性が示唆された.

著者

加藤 史訓 野口 賢二 諏訪 義雄 木村 晃 河合 雅史 高木 利光 小俣 雅志

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.68, no.2, pp.I_1396-I_1400, 2012 (Released:2012-11-15)

参考文献数

4

被引用文献数

7 12

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Field survey on coastal dike damage and scouring induced by the Great East Japan Earthquake Tsunami was conducted in the Southern Part of Sendai Plain. Erosion rate of dike cross section was estimated by using topographical data obtained by airborne laser scanner. The erosion rate tends to increase with relative height of coastal dike from the landside ground. Tsunami overtopping caused scouring at the landward toe of coastal dike, being a trigger of dike failure. Cross-sectional shape of the ground induced by scouring and thickness of tsunami deposit was estimated by portable dynamic cone penetration test and trench survey.

著者

黒澤 祐司 小林 昭男 宇多 高明 野志 保仁 遠藤 将利 古谷 真広

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.68, no.2, pp.I_1461-I_1465, 2012 (Released:2012-11-15)

参考文献数

5

被引用文献数

1

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In beach nourishment using gravel, the macadam gravel is used so that the sharp-pointed shape of gravel is of concerned. In this study, the change in the shape of gravels due to wave abrasion was investigated. Gravel samples were collected from the Jinkoji and Akashi coasts in Ibaraki Prefecture, where beach nourishment using coarse materials have been carried out since 2005, and grain size and roundness were measured. It was found that roundness of gravels with an initial value of 0.2 converged to 0.4-0.5 within four years and nine months. Due to the abrasion test of sampled gravels without steel bowls, the content of gravel was as high as 92% of all the volume after the rotation of 1200 times.

著者

後藤 浩 祖父江 一馬 有馬 勇人 石野 和男 玉井 信行 竹澤 三雄

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.69, no.2, pp.I_1386-I_1390, 2013 (Released:2013-11-12)

参考文献数

10

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The Great East Japan Earthquake occurred on March 11, 2011 and the coastal zones along the Pacific Ocean in Tohoku area have received severe damage by tsunami. Most of coastal forestations have been severely damaged or swept away due to a gigantic tsunami. In this paper, historical background of coastal forestation was studied by detailed literature surveys. An instructive formula was developed between damage level of houses and a distance from coastal forestation by field investigations at the coast of Sendai plain. Furthermore, damage level of houses was clarified as a function of inundation depth of tsunami with influence of a housing code.

著者

内田 吉文 本多 和彦 吉村 藤謙 間瀬 肇 加藤 英紀 片山 美可 米澤 泰雄

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.67, no.2, pp.I_1366-I_1370, 2011 (Released:2011-11-09)

参考文献数

7

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In the Ise Bay, there is a problem of drifting debris. This study examines the validity to use an Artificial Neural Network (ANN) for the prediction of collection position of the drifting debris. The ANN model predicting the positions of debris generation and debris accumulation is constructed by checking suitable input data and ANN parameters and transfer function. The resulting ANN gives good predictions: 1) The fit ratio of the drifting debris generation positions is 83%; 2) The fit ratio of drifting debris accumulation positions is more than 50%; and 3) In front of Yokkaichi city and southward of Centrair (The central Japan International Airport) are the main places where drifting debris gathers.

著者

後藤 仁志 Khayyer Abbas 五十里 洋行 堀 智恵実

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.65, no.1, pp.41-45, 2009 (Released:2010-02-09)

参考文献数

7

被引用文献数

1

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The paper presents a 3D-CMPS method for refined simulation of a plunging breaking wave and resultant splash-up. The Corrected MPS (CMPS) has been extended to three dimensions and 3D-CMPS method has been developed on the basis of 3D-MPS method. To enhance the computational efficiency of the calculations, the parallelization of 3D-CMPS method has been carried out with two different solvers of simultaneous linear equations corresponding to the Poisson Pressure Equation (PPE). The parallelization has been performed based on a dynamic domain decomposition strategy for an optimized load balancing among the processors.

著者

園田 吉弘 滝川 清 齋藤 孝 青山 千春

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.68, no.2, pp.I_1026-I_1030, 2012

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We examined fluctuation about sedimentary environment and benthic biota of the Okigamisenishi point in Inner Ariake Sea. and focused on the impact of formation of oxygen-deficient water and resuspension of fine sediments with the typhoon in Summer 2006. As a result, about the relation between oxygen-deficient water and benthos, benthos with poor mobility as Annelida, Mollusca fluctuated corresponding to change of dissolved oxygen, while Arthropod escaped from the ocean space of oxygen-deficient water. About the relation between water contet of fine sediments and benthos, decrease in water content was increased the stability of the sediments, and benthic species and population increased. Dissolved oxygen and water content are an important environmental factors of the benthic habitat.

著者

吉野 真史 丸山 和英 木村 克俊

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.67, no.2, pp.I_1246-I_1250, 2011

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A person in a shallow beach near shoreline at Moheji Coast in Hokkaido died due to wave that had ordinary height in November, 2008. In order to reproduce the situation of the fall accident in a shallow beach, two-dimensional hydraulic model tests and numerical calculation were carried out to examine the wave force on a human body. The fall limit ratio was newly proposed for estimating the qualitative risk of person's fall accidents, and its applicability was confirmed. Based on these results, possibilities of person's fall accidents with ordinary waves were confirmed, and the safety tide level was shown for some wave conditions. A basic idea of the safety management was also proposed for shallow beach.

著者

湊 太郎 横山 由香 大石 友彦 佐藤 義夫

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.68, no.1, pp.54-59, 2012 (Released:2012-10-19)

参考文献数

26

被引用文献数

1

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豊かな水産資源を効率的かつ持続的に利用するためには,より健全な沿岸海域環境を取り戻し,それを長期にわたって維持する必要がある.本研究では,海域環境改善の手法として,底質に光を照射し付着藻類の光合成を促すことにより,底層水の貧酸素化を抑制する方法に着目した.ここではまず,無酸素状態からの溶存酸素量の増加の可能性を調べるため,自然堆積物を用いて室内実験を行った.人工光源として,本研究ではLEDを採用した.その結果,光を照射することによって,溶存酸素量が増加し無酸素状態を脱することが確認された.このことから,底質にLEDを用いて光を照射する方法は,無酸素状態の環境を改善するために非常に有効な手段であることが明らかとなった.

著者

根本 信 高瀬 嗣郎 長谷部 大輔 横田 崇

出版者

公益社団法人 土木学会

雑誌

土木学会論文集B2(海岸工学) (ISSN:18842399)

巻号頁・発行日

vol.65, no.1, pp.346-350, 2009 (Released:2010-03-05)

参考文献数

15

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With the progress of recent seismological research, we have understood that slip distribution of earthquake fault rupture is generally heterogeneous and has fault asperity. However this heterogeneity of fault slip has not been considered enough in scenario earthquakes of tsunami prediction. In this study (1) we performed inversion analyses of past three large earthquakes in Japan sea (1964 Niigata, 1983 Nihonkai-Chubu and 1993 Hokkaido Nansei-Oki) using tsunami height data in order to investigate the characteristics of slip heterogeneity, (2) based on the inversion results, we proposed a modeling procedure of fault asperity on tsunami source model of scenario earthquakes.