All issues
Volume 44 (2003 - 200･･･
- Issue 6 Pages 331-
- Issue 5 Pages 274-
- Issue 4 Pages 213-
- Issue 3 Pages 142-
- Issue 2 Pages 84-
- Issue 1 Pages 2-
Volume 44, Issue 5
Displaying 1-5 of 5 articles from this issue
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Takashi HIGANO2003 Volume 44 Issue 5 Pages 274-282
Published: December 10, 2003
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThe building of jetties or other types of projecting walls along straight coasts has had disasterous effects on many beaches. Therefore, the problems of stabilization and restoration of the beaches are the most widespread problems on shore-control. In the coastal zone design of engineering works has been considered about the materials to be employed and the forces they must withstand. But, the modifications by the works that will introduce in the natural sedimentation processes operating in the coast and nearshore zone will be needed. The Kashima Nada beach can be divided into different types on the basis of beach topography, grain size, sand fraction composition and Froud number; scour holes beach, ridge-unnel beach, and cusp beach. The scour hole type beach is eroded inconsiderably. The ridge-unnel type is the stable beach in a change of a season. The cusp type beach is classified into the looser beaches and the steeper beaches of foreshore slope. The first beaches are being calm area, and stable or sedimentarily tendency beaches. The second beaches have a characteristic of scour holes type, and they are the stable beaches or erosional beaches. The erosional beaches are changed into a static stable beach by the making a large arcuate rate. However, it is desirable for beach enterprise to consider it with a large viewpoint because the erosional beaches are source of supply of drift sand. Enough knowledge of coastal and nearshore processes with varying accuracy and precision is obtained through processes operating in the Kashima Nada beach. It is possible to provide qualitative predictions of the effect of engineering works in the natural sedimentation processes and subsequent consequences.View full abstractDownload PDF (2101K) -
Kazuharu SAITO, Hiromistu SAEGUSA, Kunio WATANABE, Mahesh GAUTAMN2003 Volume 44 Issue 5 Pages 283-293
Published: December 10, 2003
Released on J-STAGE: March 25, 2010
JOURNAL FREE ACCESSFracrure density distribution along four bore-holes drilled by JNC, Tono Geoscience Center were analyzed by using ANN (Artificial Neural Network) and information entropy. The objective of this study is the development of technique that enables to predict the density in the deeper section of bore-hole. The obtained results are as follows.
(1) Fracture density in deeper part can be predicted by ANN model.
(2) The accuracy of prediction could be increased by using “entropy values” in ANN model.
(3) It is also found that geological structures, rock type and etc. must be well described before apply the tectonics because the stochastic property of fractures density in the function of geological condition.View full abstractDownload PDF (3755K) -
Shuzo KITAGAWA2003 Volume 44 Issue 5 Pages 294-302
Published: December 10, 2003
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThis report deals with the behavior of tunnel and the simple test in the squeezing ground. It is concluded from thecase analysis of tunneling and model experiments that squeezing pressure occurs when overburden pressure exceeds the rock strength, time dependency of squeezing pressure is not so large, and the concentration of stress in the ground around tunnel causes squeezing pressure at muddy ground only. From this point of view, I think that angle of internal friction in residual strength calculated by the cyclic box shear test is the main index for the estimate of squeezing pressure.View full abstractDownload PDF (1949K) -
Takuya YAMAGUCHI, Satoru KOJIMA, Kenji YAIRI2003 Volume 44 Issue 5 Pages 303-312
Published: December 10, 2003
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSHydraulic conductivity of drilling core specimens recovered from melanges in the Mino terrane was measured by transient pulse technique. The core specimens were taken from the melanges of middle Jurassic Kamiaso unit in the Maruyama-dam area, which were thermally metamorphosed by latest Cretaceous Toki Granite, and from the non-metamorphosed melanges of late Jurassic to earliest Cretaceous Kanayama unit. Both of them have sandstone blocks several mm to several cm in diameter within a sheared shale matrix. Coefficients of hydraulic conductivity of the former range from 10-13 to 10-15m/sec, whereas those of the latter is 10-11 to 10-15m/sec; It indicates that the melanges are low permeability rocks, and that the thermal metamorphism may decrease the hydraulic conductivity of the melanges. The coefficients of hydraulic conductivity are not mutually related with the angles between long axis of the specimen (direction of the water flow) and foliation of the melange. On the other hand, the hydraulic conductivity increases with the increases of the porosity. The melanges from the Kanayama unit show a weak relationship between the hydraulic conductivity and the amounts of sandstone blocks in the melanges ; the coefficients increase with the increase of amounts of sandstone blocks. Coefficients of hydraulic conductivity reported in published papers and measured by the in situ tests at about same depth with the specimens of this report, are clustered around 10-7m/sec.View full abstractDownload PDF (2934K) -
[in Japanese]2003 Volume 44 Issue 5 Pages 313-321
Published: December 10, 2003
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDownload PDF (6950K)
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