JaLCDOI 10.18926/15836
フルテキストURL Mem_Sch_Eng_OU_21_1_81.pdf
著者 Nago Hiroshi| Maeno Shiro|
抄録 Under the attack of storm waves, there are many destructions of coastal structures due to scouring, sinking and sliding. These types of destructions are considered to be in close relation to the dynamic behavior of sand bed around the structures. In this study the characteristics of pore water pressure and stresses in the sand bed around a breakwater under the attack of superposed waves are treated theoretically. The results show that during the crest or the trough being in front of the structure the strength of sand bed around the structure decreases notably and the unstable zone will occur.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1986-11-15
21巻
1号
開始ページ 81
終了ページ 91
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307224
JaLCDOI 10.18926/15822
フルテキストURL Mem_Sch_Eng_OU_20_2_35.pdf
著者 Nago Hiroshi| Maeno Shiro|
抄録 Under the attack of storm waves, there are many destructions of coastal structures in the forms of sinking and sliding. These types of destructions will be in close relation to the dynamic behavior of sand bed around the structures. From this point of view, in this paper, we investigate the characteristics of the pore water pressure and effective stresses in the highly saturated sand bed under oscillating water pressure theoretically. The results indicate that the oscillating water pressure induce the notable drop of strength of sand bed around the structure under certain condition.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1986-02-28
20巻
2号
開始ページ 35
終了ページ 45
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307664
JaLCDOI 10.18926/15819
フルテキストURL Mem_Sch_Eng_OU_17_1_61.pdf
著者 Maeno Shiro| Nago Hiroshi|
抄録 In this paper the liquefaction of sand bed under oscillating water pressure are treated as a basic study of the prevention works against the scouring around the hydraulic structures. The results of the former resurch show that the occurrence of the liquefaction depends on both properties of the oscillating water pressure and of the sand layer. Considering the latter properties, that is, the resistivity against the liquefaction increases with the increase of the permeability of the sand bed, we propose the displcement method as one of the prevention works, which is a method to displace the upper layer of the sand bed by the sand with large permeability. The effects of this method are investigated theoretically and experimentally. By the experimental study, it is shown that the proposed displacement method has the apparent effect to prevent the liquefaction. The experimental results are explained fairly well by the theoretical analysis based on the theory of the flow through the elastic porous media.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1983-02-25
17巻
1号
開始ページ 61
終了ページ 71
ISSN 0475-0071
言語 English
論文のバージョン publisher
JaLCDOI 10.18926/15783
フルテキストURL Mem_Sch_Eng_OU_19_1_13.pdf
著者 Nago Hiroshi| Maeno Shiro|
抄録 In this paper the theoretical method to analyse the pore water pressures in the sand bed under the oscillating water pressure is developed. In the former researchs the validity of the theoretical treatment for the one-dimensional problem has been verified. However, the one-dimensional treatment is not sufficient to obtain the precise informations concerning the many practical problems. From this point of view, in this study, we derive the fundamental equations for the general three-dimensional sand layer under the oscillating water pressure. The validity of this theoretical method is verified by experiments for the twodimensional problems.
出版物タイトル Memoirs of the School of Engineering, Okayama University
発行日 1984-11-26
19巻
1号
開始ページ 13
終了ページ 32
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307347
JaLCDOI 10.18926/15501
フルテキストURL Mem_Fac_Eng_OU_24_2_67.pdf
著者 名合 宏之| 前野 詩朗|
抄録 Many hydraulic structures are damaged by under flood flow and storm waves year after year. Many cases of dike and breakwater failure are caused by the suck out of sand from behind the revetment. This type of failure will be in close relation to the dynamic behavior of sand bed around the revetment. In this paper, from this point of view, we investigated the basic characteristics of such sand movement by small model tests and tried to explain the hydro- and soil-mechanical mechanism of this phenomenon theoretically.
出版物タイトル Memoirs of the Faculty of Engineering, Okayama University
発行日 1990-03-29
24巻
2号
開始ページ 67
終了ページ 78
ISSN 0475-0071
言語 English
論文のバージョン publisher
NAID 120002307928
JaLCDOI 10.18926/fest/11571
フルテキストURL 005_081_098.pdf
著者 Magda Waldemar| 前野 詩朗| 名合 宏之|
抄録 A dynamic response of a submarine pipeline buried in sandy seabed sediments to water loading generated by harmonically oscillating water-table vertical movements is examined in the present report experimentally and numerically. The aim of small-scale laboratory experiments was: (1) to record time-histories of pipeline vertical displacements, and (2) to observe a shape of slip surface of an overburden sand body involved in breakout together with the pipeline. A parametric study was carried out in order to investigate the influence of two meaningful factors, that is the depth of burial and the specific gravity of pipeline, on a gradual upward displacement of the pipeline. Based on a numerical finite-element 2D-analysis of the hydrodynamic pore pressure and effective stresses oscillations in the pipeline vicinity, an analysis of the pipeline stability potential is presented, in which all the experimental cases tested are verified. All important component forces (e.g., hydrodynamic uplift force) associated with floatation phenomenon of the buried submarine pipeline are considered and quantified.
キーワード submarine pipeline surface waves pore pressure floatation stability
出版物タイトル 岡山大学環境理工学部研究報告
発行日 2000-02-29
5巻
1号
開始ページ 81
終了ページ 98
ISSN 1341-9099
言語 English
論文のバージョン publisher
NAID 120002313700
JaLCDOI 10.18926/fest/11567
フルテキストURL 003_075_095.pdf
著者 Magda Waldemar| 前野 詩朗| 名合 宏之|
抄録 The response on sandy seabed sediments to a harmonically oscillating water-table, with a special consideration of the wave-induced pore-pressure oscillations around a pipeline buried in seabed sediments, is studied in the present work experimentally and numerically. The aim of the analysis was: (1) to observe a true distribution pattern of the wave-induced pore-pressure oscillations acting on the pipeline outer surface, and (2) to verify small-scale test results using numerical computations performed for a wide range of saturation conditions of seabed sediments, under the assumption of a compressible two-phase medium compound of the pore-fluid and soil skeleton, as well as a finite thickness of a permeable seabed layer.
出版物タイトル 岡山大学環境理工学部研究報告
発行日 1998-01-14
3巻
1号
開始ページ 75
終了ページ 95
ISSN 1341-9099
言語 English
論文のバージョン publisher
NAID 120002313821
JaLCDOI 10.18926/fest/11622
フルテキストURL 001_121_133.pdf
著者 前野 詩朗| 山本 哲雄| 名合 宏之|
抄録 In this paper the theoretical procedure to analyze the dynamic behavior of highly saturated sand bed around a cylindrical block under the cyclic loading of water pressure is developed. The fundamental equations were derived for the axially symmetric coordinates. Then, the finite element equations were developed to solve these fundamental equations numerically. Finally, the numerical method was verified by experiments.
出版物タイトル 岡山大学環境理工学部研究報告
発行日 1996-03
1巻
1号
開始ページ 121
終了ページ 133
ISSN 1341-9099
言語 English
論文のバージョン publisher
NAID 120002313416
著者 前野 詩朗|
発行日 1986-11-01
出版物タイトル 岡山大学環境管理センター報
8巻
資料タイプ その他
著者 前野 詩朗|
発行日 1993-09-30
出版物タイトル
資料タイプ 学位論文