Investigation of seismic-wave velocities in embankment dam body
| Project/Area Number |
17K06528
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Multi-year Fund |
|---|
| Section | 一般 |
|---|
| Research Field |
Structural engineering/Earthquake engineering/Maintenance management engineering
|
|---|
| Research Institution | Saitama University |
|---|
Principal Investigator |
Mogi Hidenori 埼玉大学, 理工学研究科, 准教授 (80261882)
|
|---|
| Project Period (FY) |
2017-04-01 – 2022-03-31
|
| Project Status |
Completed (Fiscal Year 2021)
|
| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2017: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000)
|
|---|
| Keywords | ロックフィルダム / 堤体物性 / NIOM解析 / FE-BE解析 / 伝播速度 / 減衰定数 / NIOM法 / フィルダム堤体の物性の変化 / 地震工学 / フィルダム堤体の物性変化 / 地震波の伝播速度 / 維持管理 |
|---|
| Outline of Final Research Achievements |
We applied the NIOM method (Normalized Input--Output Minimization) to long-term earthquake observation records from such as Shitoki Dam and Aratozawa Dam to determine the propagation velocities of seismic waves in the embankment, and investigated changes in soil properties. As a result, we showed that (1) the velocities of S- and P-waves decreased significantly during strong ground motions due to the 2008 Iwate-Miyagi Nairiku earthquake and the the Great East Japan earthquake of 2011; (2) in subsequent minor earthquakes the propagation velocity increased more or less in proportion with the logarithm of the number of elapsed days; (3) the damping ratio in the dam body also increased due to the principal motions of the mainshocks and decreased after them in the similar manner as seen in the results of the propagation time; and, (4) an FE/BE analysis using the estimated propagation velocities was conducted and wave-propagation characteristics in the embankment was discussed.
|
| Academic Significance and Societal Importance of the Research Achievements |
本研究ではロックフィルダムの長期間の地震観測記録にNIOM解析を適用し，堤体内の波動伝播速度と堤体物性の変化を詳細に調べた．その結果，従来は室内実験に基づいて論じられることの多い土質材料の剪断剛性の低下と数年にわたる長期間の回復過程を，地震観測記録に基づいて原位置における変化として定量的に示すことができた．また，著しい強震動による原位置における減衰比の経時変化も得られており，本研究によって工学的に重要な知見が得られたものと考えている．
|
Report
(6 results)
Research Products
(8 results)
