Selection and standards for quantitative index of classification of rock mass weathering zone in the dam shoulder of a hydropower station

This paper examines the quantitative classification of rock mass weathering zone of hydropower projects based on acoustic measurements of adit tunnel wall and refined measurements of structural surface of the entire adit tunnel according to the Chinese national standards.In addition to ratio of wave indicators stated by specifications,the other two kinds of quantitative indicators are proposed,i.e.,the number of joints per unit area and occupancy ratio of rust stained fissures.The geological roc...