Prevention of disasters due to the chemical compositions of the rocks in the slope failures damaged by the Hyogoken-Nanbu Earthquake

许多陡坡在小古肯-南部地震中遭到严重破坏。神户地区的陡坡受到断层的强烈侵蚀，风化程度很深。在降雨期间，坍塌已经蔓延开来。认为该地区边坡破坏集中的原因是严重的破碎和风化作用。这些元素是在边坡破坏的风化过程中从岩石中浸出的。在此过程中，岩石中MgO、Cao和Feo含量显著降低。这些元素的淋溶在黑云母中是显著的，因为黑云母在有水的情况下会变成蛭石和高岭石。岩石的化学成分在坡度上反映出风化等级。因此，化学成分对防止边坡破坏是有用的。边坡破坏沿矿脉方向集中。斜坡的花岗质岩石被认为是在热液作用下对粘土矿物的蚀变。花岗质岩石中的黑云母易风化，遇水易蚀变为粘土矿物。在花岗质边坡中，矿脉与边坡破坏有着密切的关系。

Many steep slopes were heavy damaged by the Hyogoken-Nanbu Earthquake. The steep slopes in Kobe district has been so strongly by the fault and been weathered deeply. The collapse has been spread during the rainfalls. The reason for the slope failure concentration is thought to be heavy crushed and weathering in this area. The element are leached from the rocks during the wethering process of the slope failure. MgO, Cao and Feo contents in the rocks are remarkably decrease during the process. Leaching of these elements is remarkable in biotite, because the biotite alters in the presence of water to vermiculite and kaolinite. Chemical composition of the rocks are in the slope reflect to weathering grade. Thus, chemical composition are useful for prevention of the slope failures. The slope failures appear to be concentrated along the vein. The granitic rocks of the slopes are thought to be alteration to clay minerals at hydrothermal. Biotite in granitic rocks is easily weathered and alters in the presence of water to clay minerals. There is a close relation between slope failure and the vein in the granitic slopes.