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Volume 7 (1997)
- Issue 4 Pages 210-
- Issue 3 Pages 140-
- Issue 2 Pages 72-
- Issue 1 Pages 4-
Volume 7, Issue 2
Displaying 1-5 of 5 articles from this issue
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Hiroyuki MORIMOTO, Hideo KIYAMA1997 Volume 7 Issue 2 Pages 72-79
Published: June 15, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDistinct Element Method (DEM) is one of numerical methods which treat the area of object as a set of many stiffness elements and the deformation altogether by tracing the motion of each stiffness elements. This paper describes a basic study on DEM to dynamic behavior of fill dam during earthquake. Dynamic analysis are executed under waves which were recorded during earthquake, the damping constant are specified by applying the analytical results of the fill dam response acceleration. As a result of these, it is indicated that this non-linear spring model could estimate stress and displacement in a bank of fill dam adequately.View full abstractDownload PDF (1793K) -
Masatoshi YOGUCHI, Toshiaki MAKIHATA, Toshio IGUCHI1997 Volume 7 Issue 2 Pages 80-89
Published: June 15, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to avoid facility destructions and operation troubles due to freezing, water intake gates of dams in the cold areas commonly adopt air bubble jet circulation systems which replace cold water at surface layer with warm water at bottom layer. Very small number of studies have been conducted on the circulation systems and the phenomena have not been cleared enough. The present paper applies a numerical simulation method based on turbulent model to a quantitative evaluation of the phenomena. A full scale test in a dock at a shipyard and a field test at Tokachi Dam were conducted, and the simulation results of heat-flow induced by air bubble jet are verified by the experimental results. A calculation method of ice melting process is obtained on the basis of the experimental data at Kanayama Dam, and a more reasonable design of water intake gates becomes possible.View full abstractDownload PDF (2248K) -
Osamu ARAI, Shuji TAKASU1997 Volume 7 Issue 2 Pages 90-97
Published: June 15, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSWater quality of dam reservoirs controlled by the ministry of construction of Japan is basically good, according to the investigation of water quality for them. But, the high level of nutrient salt in inflow river water and high turbid water of flood are represent the possibility of occurrence of temporary water quality problems in many reservoirs. The most important things for the water quality of dam reservoirs are pollutant loads running into water basin, and pollutant load control measures in the watershed that is realized step by step for a long time is the fundamental measures as well as the temporary measures with an immediate effect. We discuss the water quality control system based on the actual condition of water quality of dam reservoirs in this report. And we summarized by the present situation of water quality problems that artificial current control of dam reservoirs and environmental control of the surface layer for algae growth are very effective for preserving water quality in reservoirs.View full abstractDownload PDF (2498K) -
Mitsuo TOYODA, Hitoshi YOSHIDA, Masayuki NOBUYAMA1997 Volume 7 Issue 2 Pages 98-113
Published: June 15, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSRI method is useful for numerous data sampling of density and water content in the embankment compaction cotrol, and can considerably solve some difficulties inherent in the displacement method. However still more improvement of RI equipment is necessary to attain the sufficient measured volume together with easy and quick performance when applying to coarse fill materials. This paper describes the characteristic feafures of newly introduced RI densimeter which has been developed with the intention to clear the peculiar drawbacks away in the conventional RI method as well as its applicability to the fill materials on the basis of the comparative tests in the field.View full abstractDownload PDF (5353K) -
Yoshiaki MORI, Yasuyuki SHIMADA, Hideki YUKIMURA, Akira TAKAHASHI1997 Volume 7 Issue 2 Pages 114-123
Published: June 15, 1997
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSHard rocks with high shear strength are used for structural material of rock zones of a rockfill dam with central clay core. To obtain such hard rocks from deep underground, surface soil and weathered rock have to be excavated and then be disposed of as waste. The more the disposal, the higher the cost of dam construction. To reduce the cost, the disposal should be minimized by utilizing such waste material for dam material. This paper describes a case history of the minimization of the disposal, that is the maximization of utilized waste material, with the help of multiple regression analysis.View full abstractDownload PDF (1891K)
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