All issues
Volume 41 (2000 - 200･･･
- Issue 6 Pages 323-
- Issue 5 Pages 256-
- Issue 4 Pages 200-
- Issue 3 Pages 126-
- Issue 2 Pages 70-
- Issue 1 Pages 2-
Volume 41, Issue 3
Displaying 1-5 of 5 articles from this issue
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Shingo MASUDA, Akira OISHI2000 Volume 41 Issue 3 Pages 126-134
Published: August 10, 2000
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSMany tunnels excavated in a mountain regions frequently encounter huge amount of groundwater inflows which are confined or unconfined in geological discontinuities. Those groundwater inflows consequently incurs significant extension of construction time, increase of cost and/or environmental problems.
It is not easy, however, to estimate the amount and locations of groundwater inflow by aconventional method due to a complexity of groundwater flow. In order to solve this difficulty the ground model has been properly established by specific resistance which was obtained by CSA·MT prospecting.
This paper is concerned with one of practical methods for estimating groundwater inflow into mountain tunnels by the establishment of the ground model applying CSA·MT prospecting.View full abstractDownload PDF (3386K) -
Aiming LIN2000 Volume 41 Issue 3 Pages 135-140
Published: August 10, 2000
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSDeformation mechanisms of fault rocks in fracture zones are affected by ambient temperature, fluid pressure, confining pressure, and strain rate in the upper crust. The fracture zones recorded the deformation environment where they formed. Therefore, the fabrics of fault rocks in fracture zone are useful for determining the tectonic history, paleoseismic events and displacement sense of active faults. In this study, we give some examples of fault rock fabrics in trench and fault outcrops in the active fault zones of the Gosukebashi and Mitoge faults in central Japan to show the analysis method of fault rock fabrics in fracture zones and to point out some problems in active fault study and engineering geology.View full abstractDownload PDF (2897K) -
Yoshikazu YAMAGUCHI, Noboru OKABE2000 Volume 41 Issue 3 Pages 141-149
Published: August 10, 2000
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSFoundations for embankment dams are often composed of soft rocks in Japan. Therefore, it is important to precisely predict deformation of the foundation due to an embankment to evaluate the safety of the dam and its foundation. Plate loading tests are generally utilized to evaluate the deformation characteristics of dam foundations. Looseness in surface layer due to excavation could affect the accuracy of plate loading tests. We made numerical study using FEM analysis on the influence of looseness on results of plate loading tests. Two evaluation methods of deformability of the foundations excluding the influence of looseness in surface layer are also studied. One is the method using observed vertical strains in the ground along the central axis of the circular loading plate, the other is the method using the plate loading tests with three circular plates of different diameters.
Consequently, the larger the magnitude of depth and degree of looseness is, the larger the evaluation error of the deformability is. In addition, it is found that two proposed methods make it possible to evaluate deformability of the foundation without the influence of looseness in surface layer.View full abstractDownload PDF (2228K) -
Wataru HIROSE, Jun TAJIKA2000 Volume 41 Issue 3 Pages 150-154_2
Published: August 10, 2000
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSPhreatomagmatic eruption has occurred at the western flank of Usu volcano, southwestern Hokkaido, northern Japan, at 31 March 2000. Surrounding towns have been seriously damaged and refuge has been prolonged for three months, because the eruptive vents have formed close to residence category of surrounding towns and the main traffic routes, and the eruption has involved remarkable crustal movement. Serious damages by crustal deformations (such as many pressure ridges, cracks, buckling deformations of the kerbstones, and landslide-like surface movement), uplift, ballistic ejecta, mudflow, earthquakes occurred near the volcano. Important national routes (national roads, railways, and the highway), houses, buildings, water pipes, transmission lines, retaining walls, bridges have been damaged or destroyed. On the other hand, sites of the vents and the time of eruption have been predicted by scientists based on the sites of the crustal movement and the earthquake foci. Hazard map of the volcano was corrected based on the observation results and refuge has been done before the eruption. So no victim occurred until now. This case indicates that appropriate hazard map and the effective utilization of it can decrease the disaster.View full abstractDownload PDF (3411K) -
Akito NAKASUJI, Masahiro TANIUCHI, Masaaki SANO, Satoru TUKAMOTO, Keny ...2000 Volume 41 Issue 3 Pages 155-164
Published: August 10, 2000
Released on J-STAGE: February 23, 2010
JOURNAL FREE ACCESSThe large earthquake with Ms 7.7 struck central Taiwan on Sep. 21, 1999, and had ten times as much seismic energy as 1995 Hyogo-ken Nanbu Earthquake. Nantou and Taichung County near the epicenter were most badly hit by the earthquake, and in all Taiwan 2, 321 people were killed and more than 52, 000 buildings were collapsed or damaged till Oct. 11, 1999. We investigated the disaster area one month after the earthquake had occurred. This report outlines the result of the investigation, and especially describes the relationship between soil and the damage to city facilities, and between earthquake surface fault and the damage to civil engineering structures.View full abstractDownload PDF (4018K)
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