著者

井岡 聖一郎 岩月 輝希 酒井 利彰 石島 洋二

出版者

日本水文科学会

雑誌

日本水文科学会誌 (ISSN:13429612)

巻号頁・発行日

vol.37, no.4, pp.287-293, 2007-11-30 (Released:2009-03-27)

参考文献数

33

被引用文献数

1 2

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Redox potential (Eh) is one of the most important physico-chemical properties of groundwater. Groundwater Eh have been studied in terms of safety of high-level radioactive waste disposals, water resource management and so on. As the results, it is getting clear that redox potential of deep groundwater in sedimentary and crystalline rocks have a remarkable variability. For example, some reported Eh values of deep groundwater decrease with increasing depth, i.e. with residence time. However, there are few reports showing data measured in situ. Only some Eh values of deep groundwater measured from research borehole drilled at crystalline rocks in Japan and Sweden have been reported. Between 200 and 1000m depth, the Eh values of the deep groundwater range from about 0 to -400mV.This essay first briefly summarizes methodology for Eh measurement and reports Eh values of deep groundwater. Then, it discusses the remaining issues of Eh measurement that are to develop of measurement technology applicable for various geological environments and to understand the redox evolution process through the groundwater flow system.

著者

藤井 義明 石島 洋二 後藤 龍彦

出版者

一般社団法人 資源・素材学会

雑誌

資源と素材 (ISSN:09161740)

巻号頁・発行日

vol.111, no.14, pp.993-1000, 1995-12-25 (Released:2011-01-27)

参考文献数

16

被引用文献数

1

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In Akabira Colliery, a decision was made to change the angle of influence for the cone-shaped shaft pillar from 60° to 80° in 1985. Mining in the former pillar areas started in 1986 and 2.2 million tons of coal was safely extracted before the mine closure in 1994.Damages have been induced in four levels along the concrete block-lined shaft having length of 680m. It was concluded through observation of lining, monitoring of displacements along the shaft axis and three dimensional elastic stress analysis that the main factors which induced the lining damages are (1) fault slips due to increase of shear stress, (2) increase of vertical stress component or decrease of minimum principal stress in the horizontal plane and (3) stress concentration around roadways connecting to the shaft.A consideration on a reasonable monitoring scheme for shaft damages was also shown.

著者

島内 洋志 氏平 増之 鍵和田 忠男 菅原 隆之 石島 洋二 関 忠郎

出版者

The Mining and Materials Processing Institute of Japan

雑誌

資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan (ISSN:09161740)

巻号頁・発行日

vol.122, no.3, pp.119-128, 2006-03-25

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In the transportation system using a large scaled dump truck, it is important to replace a wheel safely, quickly and easily when a wheel is burst or too much abraded partially. Conventionally, wheel replacement work has been depended on the replacement machinery for exclusive use. Considerable amount of expenditure was necessary to purchase the replacement machinery for exclusive use. Because of this reason, development of wheel replacing unit (handler unit ) has been expected for holding down the production cost.<BR>In this study, motion of a wheel replacement handler was analyzed both theoretically and experimentally, then handler unit was developed and wheel replacement test was carried out. Results obtained from the study are as follows; 1) Optional height of the axis of the large diameter wheel which is to be replaced can be adjusted easily, applying the analyzed equation obtained from theoretical study on the link motion. 2) It was found that a large scale wheel supported by a pair of steel pipes of which diameter and weight were 3.6 m and 5.2 t respectively could be rolled for setting the bolt holes to the bolt positions, when the pipe diameter was larger than 4 in. 3) As a result of rolling test for a large scale wheel using a pair of steel pipes of which diameter were 7in, it was proved that setting work of bolt holes to the bolt positions could be done within the time of 14-20 min. 4) Conclusively, it can be said that the handler unit newly developed in this study has the wide applicability, simplicity and cost performance comparing with conventional wheel replacing machinery.