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Volume 8 (1998)
- Issue 4 Pages 244-
- Issue 3 Pages 168-
- Issue 2 Pages 71-
- Issue 1 Pages 5-
Volume 8, Issue 2
Displaying 1-8 of 8 articles from this issue
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Hiroshi TERATA1998 Volume 8 Issue 2 Pages 71-84
Published: June 15, 1998
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSTwo methods are established to provide resistance against wave forces to the shell type double leaf gate which is often installed in salinity barriers located in the vicinity of a river estuary. One is the double leaf gate in reverse arrangement and another is the ordinary arrangement with a truss type gate bottom. The latter has been in operation for more than 15 years at the Yodo River Great Barrier whose gate spans are amongst the largest in Japan. This paper includes an explanation of how to reduce the hydraulic downward force which may act on the reverse arrangement gate and analyses the wave energy dissipation mechanisms and the structural behavior of a gate having a truss type gate bottom.View full abstractDownload PDF (3119K) -
Hiroo SHIOJIRI, Minoru UEDA1998 Volume 8 Issue 2 Pages 85-92
Published: June 15, 1998
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAccurate prediction of earthquake response of a dam is necessary for reliable evaluation of safety of the dam. In the computation, appropriate numerical modeling should be done to get trustworthy results, and it is important to validate the modeling of dams by comparing computed results with observed ones. In this paper, the response of Hitokura concrete gravity dam to the 1995 Hyougoken-Nanbu Earthquake is simulated by using a computer code developed for the analyses of two dimensional dam-foundation rock-reservoir water interaction. Extensive finite element studies are conducted, and the results are compared with recorded responses. Appropriate material properties of dam and foundation rock to be used in the analysis and a rational procedure to determine them are discussed.View full abstractDownload PDF (1561K) -
Hongyuan ZHANG, Tatsuo OHMACHI1998 Volume 8 Issue 2 Pages 93-101
Published: June 15, 1998
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis paper deals with seismic cracking of concrete gravity dams. First, the nonlinear tensile behavior of concrete is represented by the smeared crack model. The solution method of dynamic equation is discussed and improved to be consistent with the smeared crack model. Then, the seismic cracking of Koyna Dam is reproduced, to demonstrate the validation of such a nonlinear analysis on cracking in concrete gravity dams during strong earthquakes. Finally, the effect of hydrodynamic pressure inside cracks on the cracking in dam body is investigated and the calculation shows that hydrodynamic pressure inside cracks tends to increase the length of cracking.View full abstractDownload PDF (1850K) -
Mizuho IMAMURA1998 Volume 8 Issue 2 Pages 102-116
Published: June 15, 1998
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSFlood control operation systems for dam reservoirs are composed of elements such as pre-flood control operation, normal flood control operation, extra-flood control operation and after flood control operation. Physical and mathematical analyses were carried out and characteristics of each element were defined physically and mathematically. Through these analyses several improvements were suggested. An automization of flood control will be feasible if these improvements are systemized.View full abstractDownload PDF (3362K) -
Josuke KASHIWAI, Toshiyuki SAKURAI1998 Volume 8 Issue 2 Pages 117-125
Published: June 15, 1998
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn order to check a newly constructed dam and reservoir, trial filling is carried out. Recently, trial filling requires longer time, mainly due to the shortage of inflow volume, resulting in the delay of start of dams' operation. In the case of trial filling is not over in one non-rainy season, controlling water level to secure storage capacity during rainy season is necessary. This influences the length of trial filling term. This paper discusses the safety of water level rising during trial filling and indicates the relationship among storage capacity for flood operation which satisfies required safe probability, the number of experienced rainy seasons and allowance of water level rising. Through the model dams' calculations, this paper also examines actual return periods for deciding flood operation capacities and the numbers of experienced rainy seasons.View full abstractDownload PDF (1928K) -
Isao NAGAYAMA, Kazuo WATANABE, Munehisa MACHIDA, Hiroyuki ARAI1998 Volume 8 Issue 2 Pages 126-134
Published: June 15, 1998
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis paper discusses the mixture design of high fluidity concrete with the large maximum size of aggregate, and its fluidity and resistance to segregation, taking account of use in the dam construction. The followings are concluded from the experiment. (1) The mixture of high fluidity concrete is easily determined when the mixture of cement paste and the mixture of mortar are studied in advance of the mixture of concrete. (2) The use of larger maximum size of aggregate can reduce the mortar content (cement content) in concrete, as long as the maximum size is no larger than 40 mm.View full abstractDownload PDF (1688K) -
Kiyonori MIYASHITA, Takao SAKUMA1998 Volume 8 Issue 2 Pages 135-141
Published: June 15, 1998
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn the recent development of dam construction, there has been an increasing number of dams constructed on the soft rock foundation formed in or after the Tertiary era. This tendency applies to the construction project of Shirokawa Dam whose site geology is featured by sand and mudstones of Neogene Tertiary cenozoic era. Those stratums are proned to slaking as verified by experimental tests conducted locally at the site and at the laboratory. This report contains the result of case studies on the experimental test method adopted to clarify a more accurate aspect of slaking and the construction method for prevention against possible deterioration of the excavated face of foundation.View full abstractDownload PDF (1740K) -
Kuniaki YOSHIOKA, Toshiyuki SATO, Yukihiro IKEGUCHI1998 Volume 8 Issue 2 Pages 142-151
Published: June 15, 1998
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis paper presents a new technology for pond surfacing based on the use of rubber sheet which will be used in the construction of the world's first seawater pumped-storage power plant. The plant, presently under construction on Okinawa Main Island, is planned and financed by the Ministry of International Trade and Industry (MITI), Japan, with the Electric Power Development Co., Ltd. (EPDC), under a consignment contract with MITI, being in charge of surveys, research, designs and supervision of the construction. In designing this pilot plant, the sheet foundation design, the sheet anchoring method, selection of the sheet material, structural designs, and leakage water detection and dewatering system have been newly developed in consideration of the requirements imposed on a seawater pumped-storage power plant. This paper presents the design concept, construction work and the method and outcome of the quality management.View full abstractDownload PDF (3202K)
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