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Volume 10 (2000)
- Issue 4 Pages 276-
- Issue 3 Pages 169-
- Issue 2 Pages 82-
- Issue 1 Pages 5-
Volume 10, Issue 3
Displaying 1-8 of 8 articles from this issue
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Hiroshi TERATA2000 Volume 10 Issue 3 Pages 169-182
Published: September 15, 2000
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe answer to the question why the contact surface has extremely high strength is made based upon stress status in the contact portion and the dislocation theory for the yielding in material. Experimental results of the deformations of surfaces under the statical and repeating load beyond elastic limits are reanalyzed and the influence of plastic deformations upon the gate operative loads are shown.View full abstractDownload PDF (3508K) -
Yutaka OYAGI, Shiro KAI, Yasuhisa HIROTA2000 Volume 10 Issue 3 Pages 183-193
Published: September 15, 2000
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSMany gravity check dams have been constructed in ground sliding areas. However gravity dams have proved, due to their large volume, not to be economical and moreover to need a long construction period. In this paper we propose a thin semi-gravity check dam, the stability of which is assured by anchors fixed on the upstream side as well as by reinforcements for tensile stress. Therefore, because of its thinness, this dam can be constructed more economically. This paper describes the design method of the semi-gravity check dam employing with anchors. In the design method, the most suitable upstream slope, as well as the tension in the anchors, were determined by usual stability calculation. In order to determine the stress distribution in the dam body, elastic analysis was carried out by two-dimensional finite element method. Eventually, as results from the analysis, we disposed the necessary reinforcement in the dam structure.View full abstractDownload PDF (2630K) -
Tadaomi OUCHI, Tadahiko FUJISAWA, Masaki TANIGUCHI2000 Volume 10 Issue 3 Pages 194-210
Published: September 15, 2000
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn the RCD construction method, which uses a wide variety of construction equipment operated concurrently in the placement area, there might be cases where the full performance potential of individual pieces of equipment is not utilized mainly because of interferences and time lost due to waiting. This paper reports on a newly developed simulation model capable of expressing a system of concrete handling and placing equipment used at a dam site and studies the model's applicability to construction programme.View full abstractDownload PDF (5587K) -
Tetsuya SUMI2000 Volume 10 Issue 3 Pages 211-221
Published: September 15, 2000
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSSedimentation management of reservoirs is one of crucial issues to realize sustainable development of water resources for next generations. Recently, sediment-flushing techniques have been applied to Dashidaira dam and Unazuki dam in the Kurobe River, but necessary amount of water and prerequisite conditions for dams where flushing can be applied have not been rarely discussed. This paper compares water-sediment balances during flushing operations both for Dashidaira Dam and other examples in the world, and discusses flushing efficiencies of each operation. Those results are also applied to study feasibility of sediment flushing operations.View full abstractDownload PDF (2590K) -
Yoshio NAKAMURA, Masahiro YAMAGUCHI, Kunitomo NARITA2000 Volume 10 Issue 3 Pages 222-231
Published: September 15, 2000
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSStress release produced by excavation in the ground causes reduction in confining pressure, which in turn results in swelling of soils and the decrease in the shear strength required for slope stability. In the natural ground composed of a soft sedimentary rock like mud stone, which is more or less expansive and/or ready to show weathering, change in soil properties, weakening and softening, due to stress release can be another influential factor for slope instability in addition to the mechanical factors noted above. This paper concerns behavior of stress release and expansion deformation in the ground due to excavation, and the distribution of local safety to discuss mechanism of instability of cut slopes. FEM excavation analysis was carried out for several representative simple slopes by taking pre-compression effects on strength into account. The overall safety against circular sliding surfaces was also discussed by comparing the results from FEM and those by a conventional limit equilibrium approach of slope stability.View full abstractDownload PDF (2535K) -
Hongyuan ZHANG, Tatsuo OHMACHI2000 Volume 10 Issue 3 Pages 232-240
Published: September 15, 2000
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThis study deals with seismic cracking and strengthening of concrete gravity dams. A coupled FE-BE method is developed for the nonlinear analysis of a dam-foundation-reservoir system in two dimensions, in which the dam-foundation-reservoir interaction is evaluated rigorously and the cracking of concrete is represented by the smeared crack model. Then seismic cracking of a concrete gravity dam under intensive shaking is analyzed and the effects of reservoir and foundation on the seismic cracking of dam body are investigated. Finally, some measures are suggested to reduce tensile stress and cracking in the dam body and these measures are evaluated by the numerical analyses.View full abstractDownload PDF (2250K) -
Hiroshi TAKAHASHI, Hideo MORINO, Kazuhiro ONUMA2000 Volume 10 Issue 3 Pages 241-253
Published: September 15, 2000
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSMaking good use of rock for concrete aggregate or rock fill dam material is important from the viewpoint of cost effectiveness and preserving environment. However, there are many issues to be solved, such as establishing the standard of required quality and the method to discriminate rock. Especially, it is required to establish the method to discriminate rock rationally and rapidly. In this paper, we discuss these issues and propose the method to discriminate. This method consists of followings. 1) Rapid measurement of density and absorbed moisture by boiling the rock, 2) Particle size analysis using shaking screen and mathematical accuracy, 3) Point load test for many rocks. With these points, we proposed a practical system to discriminate rock at quarry area of rock fill dam site.View full abstractDownload PDF (3042K) -
Study Team on the Geology and Foundation of the2000 Volume 10 Issue 3 Pages 254-267
Published: September 15, 2000
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSDownload PDF (4132K)
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