HOME    About this site    mypage    Japanese    library    university    Feedback

University of the Ryukyus Repository >
Faculty of Agriculture >
Bulletin >
The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus >
No.24 (1977/12) >

 
Title :一滴の連続的な落下による土塊の破壊試験(農業工学科)
Title alternative :Disintegration test of the soil block using continuous falling of a water drop(Department of Agricultural Engineering)
Authors :翁長, 謙良
宜保, 清一
Authors alternative :Onaga, Kenryo
Gibo, Seiichi
Issue Date :1-Dec-1977
Abstract :一滴の連続的落下による土塊の破壊試験を行ない, 破壊率と含水比および水滴の運動エネルギーとの関係を調べた結果2,3の知見を得た。(1)水温が高いほど単位時間当りの水滴数は増加し, 水滴径は小さくなる。したがって, エネルギー的には水滴径を大きくすることによって落下高さの過不足を補うことができる。(2)破壊率と土塊の初期含水比および水滴数の関係を6つのタイプに分類することによって水滴の衝撃に対する土構造の安定度の判別が容易になる。(3)一滴の連続的落下試験は人工降雨による結果とよい一致をみた。(4)破壊率と水滴の運動エネルギーの間には相関関係がある。(5)水滴(4mm径)による土塊の破壊試験には2.5m前後の落下高さがよいようである。
Disintegration tests of small soil block using falling water drops were made in order to investigate the relation between percentage of disintegration and the change of moisture contents, the kinetic energy of water drops. The apparatus for producing drops is shown in Fig. 1 and the height of hypodermic needle from the testing soil were 6.5m, 2.5m, 1.0m and 0.5m respectively. Distilled water was employed and the three testing soils (YAGAZI-silty KIN-clayey, TOMIGUSUKU-clayey) were used in this investigation. The results of the investigation were as follows : 1. The higher the water temperature the more increase the number of drops per unit time. 2. The mass of a drop was influenced by water temperature and higher of the water temperature the smaller the mass of a drop. 3. By enlarging the size of drop, the lack of kinetic energy-falling height- was made up. 4. The relation between percentage of disintegration and number of drops can be classified into six types as sown in Fig. 4,and this makes easy the judgment of stability of soil against the impact of drops. 5. The test result by continuous falling of a water drop resembles by artificial rainfall closely. 6. There were correlation between the percentage of disintegration and the kinetic energy of water drops. 7. 2.5 meters high of falling water drops will fit in this investigation.
Type Local :紀要論文
ISSN :0370-4246
Publisher :琉球大学農学部
URI :http://hdl.handle.net/20.500.12000/4249
Citation :琉球大学農学部学術報告 = The Science Bulletin of the Faculty of Agriculture. University of the Ryukyus no.24 p.439 -448
Appears in Collections:No.24 (1977/12)

Files in This Item:

File Description SizeFormat
KJ00000162607.pdf609KbAdobe PDFView/Open