全北 益山地域 化崗岩採石場에 있어서 化崗岩 造岩鑛物內의 microcrack의 方向性 = Perferred Orientation on of Microcracks in Iksan Granite Quarrying Fields

다국어 초록 (Multilingual Abstract)

Granitic rocks have three mutually perpendicular planes along which they are easily splitted. These planes are called, in quarryman's terminology, as rift, grain and hardway planes, in order of easy of splitting and called as "Kyeol" in Korea. The phenomenon of rifting in granitic rocks have been known for a long time. Despite of their importance in determining mechanical behavior of granitic rocks, these planes have not received the attention without quarrymen. Experimental results show that rifting depend on the preexisting microcrack behavior preferentially oriented along these planes.
In this paper, in situ orientation of the three planes of anisotropy in granite was at first investigated with the empirical aid of quarrymen in Iksan areas. The azimuthal variation of the p-wave velocity was measured and the feature of the cracks was investigated on thin sections of the rock with an optical microscope. The micro-defects were classified into open cracks and healed cracks.
In the specimens, rift plane consists of open cracks within the quartz's grains and the strikes are nearly parallel to the horizontal plane. Thus grain and hardway plane in vertical. Grain plane consists of open cracks and healed ones within the quartz, while hardway plane consists of a few cracks within the quartz and often consists of healed cracks within the feldspar grain.