Application of hierarchical cluster analysis in classification of tunnel rock masses

Nowadays there are many methods used in classification of tunnel rock masses, most of them are based on a large number of engineering examples, and they divide rock masses into different stability levels. As set up with the summary of numerous and dispersed data, they have universal usability. However, at the same time they lost pertinence for the specific case, and they can not accurately reflect the characteristics of different rock masses in different examples. So hierarchical cluster analysis is exploited to classify tunnel rock masses only for one example or examples in one region according to the dominant factor which affects the engineering properties of rock section most, and the interrelationship of different categories has been studied. Through the application in specific example, a pertinent hierarchical system has been established, which makes the rock classification to be a dynamic process.