WEKO3
アイテム
土石流被害軽減のための実践的な土石流速推定手法の探求
https://doi.org/10.18880/0000007694
https://doi.org/10.18880/0000007694b9cd29de-2f47-4fad-aaf6-c16311487944
| 名前 / ファイル | ライセンス | アクション |
|---|---|---|
md_aftabur_rahman-review.pdf (238.7 kB)
|
|
|
|
md_aftabur_rahman-thesis.pdf (7.0 MB)
|
|
| Item type | 学位論文 / Thesis or Dissertation(1) | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 公開日 | 2017-02-17 | |||||||||
| タイトル | ||||||||||
| タイトル | Ascertaining a hands-on approach to estimate debris flow velocities for rational debris hazard mitigation | |||||||||
| 言語 | en | |||||||||
| タイトル | ||||||||||
| タイトル | 土石流被害軽減のための実践的な土石流速推定手法の探求 | |||||||||
| 言語 | ja | |||||||||
| 言語 | ||||||||||
| 言語 | eng | |||||||||
| キーワード | ||||||||||
| 主題Scheme | Other | |||||||||
| 主題 | mud-marks, SPH, super-elevation, velocity, Debris flow | |||||||||
| 資源タイプ | ||||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_db06 | |||||||||
| 資源タイプ | doctoral thesis | |||||||||
| ID登録 | ||||||||||
| ID登録 | 10.18880/0000007694 | |||||||||
| ID登録タイプ | JaLC | |||||||||
| アクセス権 | ||||||||||
| アクセス権 | open access | |||||||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||||||
| 著者 |
MD., Aftabur Rahman
× MD., Aftabur Rahman
|
|||||||||
| 抄録 | ||||||||||
| 内容記述タイプ | Abstract | |||||||||
| 内容記述 | Debris flow is one of the shattering natural disasters, mostly ensuing in mountainous areas. Rational estimation of debris flow velocity is one of the key issues in debris hazard mitigation. Among the various procedures, back-calculation of debris flow velocity is a widely used approach. Back-calculation procedure includes determinations of super-elevation and channel properties, and velocities are calculated using the forced-vortex equation (??=√gRΔ?/kb). A debris mass, when travels through a curved flume, leaves the highest flow mark on the outer bend, and the difference between the flow depths of outer and inner bends is referred to as ‘super-elevation’. However, in a post-flow field investigation, only the highest flow marks on both inner and outer bends are visible, which does not portray the actual maximum super-elevation that must have been reached in the unsteady flow event, and eventually leads to a misjudgment of the real velocity. Another important parameter of forced vortex equation is the channel radius of curvature. Any natural channel has hardly been a circle, rather it has varying curvature. How the curve is approximated can affect velocity estimation. Considering the unsteady nature of debris flows, this research work aims to figure out a coherent way of estimating debris flow velocities. Therefore, a series of numerical curved flume tests using Smoothed Particle Hydrodynamics (SPH) are carried out to check the aptness of the mud-marks derived velocities. Estimated velocities from flow marks underestimate the actual velocities near the source, while they converge on the actual velocities as the distance to source increases. Based on the simulations, a best fit curve is proposed to adjust the mud-marks derived velocities. Law of similarity allows to apply the findings from these small scale simulations to the real debris flow problems. Three debris flow events in Japan are taken for the validation of the proposed procedure and adjusted velocities are proven to be consistent with verbal evidences and previous analyses. | |||||||||
| 言語 | en | |||||||||
| 書誌情報 |
発行日 2016-09-16 |
|||||||||
| 著者版フラグ | ||||||||||
| 出版タイプ | VoR | |||||||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||||||
| 国立国会図書館分類 | ||||||||||
| 主題Scheme | NDLC | |||||||||
| 主題 | UT51 | |||||||||
| 学位名 | ||||||||||
| 学位名 | 博士(工学) | |||||||||
| 学位授与機関 | ||||||||||
| 学位授与機関識別子Scheme | kakenhi | |||||||||
| 学位授与機関識別子 | 12701 | |||||||||
| 学位授与機関名 | 横浜国立大学 | |||||||||
| 学位授与年度 | ||||||||||
| 値 | 2016年度 | |||||||||
| 学位授与年月日 | ||||||||||
| 学位授与年月日 | 2016-09-16 | |||||||||
| 学位授与番号 | ||||||||||
| 学位授与番号 | 甲第1858号 | |||||||||
