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Volume 4 (1994)
- Issue 16 Pages 5-
- Issue 15 Pages 14-
- Issue 14 Pages 5-
- Issue 13 Pages 5-
Volume 4, Issue 15
Displaying 1-5 of 5 articles from this issue
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Kenji IMAMURA, Noriaki SIGENAGA, Tosiro AKETA, Sin MAEKAWA1994 Volume 4 Issue 15 Pages 14-24_1
Published: September 15, 1994
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSExperimental study on hydraulic excitation force and cavitation at concave of a pipe branch opening fitted on a conduit wall is presented.
Excitation force with a similar feature to cavity oscillation appears in a pipe branch, too. The excitation force was grapsed by model test detecting resonance under flow condition of fL/V=0.5, 1 and so on, where f, L and V mean frequency, branch pipe diameter and flow velocity. Countermeasure for the excitation will be to make a branch flow into the pipe branch from a flow past the branch opening, or to make an inflow to the flow past the branch opening from the pipe branch.
As for cavitation, attention should be paied to location of a branch. To locate a branch in a stagnation region that is caused by a partial opening gate makes it easier to attain a non-cavitation flow condition. A bellmouth opening works well to attain a non-cavitation condition in the stagnation region.View full abstractDownload PDF (1777K) -
Haruhisa KOJIMA, Hideya HATA, Yasuo HATAYAMA, Syuuji TAKASU1994 Volume 4 Issue 15 Pages 25-35
Published: September 15, 1994
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSHigh-pressure radial gate is the most popular type of high pressure discharge regulating equipment for domestic flood control in dam. For the evaluation of gate arm rigidity, especially for the calculation of effective buckling length, the calculation formula specified in the Specification for Highway Bridges is generally applied in Japan. But in case of gate structure, the applied structural figures and rigidity conditions are generally different from the descriptions in the Specification for Highway Bridges, and it is often pointed out the existence of difficulty of application of Specification for Highway Bridges to the gate structure directly. Accordingly we made the analysis on the effective buckling length of radial gate to compare the case of Highway Bridges.View full abstractDownload PDF (1639K) -
Syoiti NODA, Kazumi SUZUKI1994 Volume 4 Issue 15 Pages 36-45
Published: September 15, 1994
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs to dam on a small scale, turn out factor of cost jamp great at the rate of temporary works occupy to construction cost of dam in controst on a large scale dam.
On the occasion of construction at the Okusaru dam, be description about that instance diversion of a river, energy dissipator, groutong, concrete combination design and so on be measure of various about that reduction of construction cost.View full abstractDownload PDF (1530K) -
Yasuo YONEDA, Yasuo HORI, Takayoshi NAKAYAMA, Kazuyoshi YOSHIHARA1994 Volume 4 Issue 15 Pages 46-54
Published: September 15, 1994
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSTo improve the safety and productivity of the placing of dam concrete, the development of an automatic placing system is well under way. Full automation of the batch plant and transfer car at the banker line has been realized.
This system is remotely controlled from the concrete placing point by a wireless handy terminal. Also, this system includes an automatic consistency measurement device which is able to carry out the quality control of fresh concrete immediately at the outlet of the concrete mixer.
This system has proved itself by producing good results at the ICHINOKI DAM PROJECT in NARA Pref.View full abstractDownload PDF (1944K) -
Kazuo HARITA, Yokito SUGIMURA, Nobuyuki SHIRAKAWA, Takanobu KUWAJIMA1994 Volume 4 Issue 15 Pages 55-63
Published: September 15, 1994
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDams are of vital importance to our environment, and their effect on society if anything abnormal should occur is inestimable. It is therefore necessary to ensure their permanent safety by monitoring dam behavior accurately. Although there are accumulated data concerning measurement items and measuring frequency, no techniques have been established yet regarding how the reliability of measured data can be judged and abnormal data be conditioned, a necessary procedure for practical operation control.
With the importance of maintaining the safety of dams pointed out, reduction of manual labor is being sought after. Therefore, it has become necessary to establish a method for evaluating the safety of dams using a small amount of manual labor.
For these reasons, studies of the above problems are being conducted. This is a current summary of discussions about the above-mentioned problems concerning zoned rockfill dams.View full abstractDownload PDF (1807K)
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