Multivariate Clustering Analysis of the ECRB Cross Drift Discontinuities, Yucca Mountain Project


A great deal of effort has been made to characterize the nature of the discontinuities of the Yucca Mountain proposed nuclear waste repository. Discontinuity sets were identified, using orientation only as the basis of cluster analysis. Other discontinuity characteristics such as lithology fracture frequency, continuity, roughness, aperture, and infilling have been analyzed, but separate and divorced from the clustering analysis.

The across drift data has been re-analyzed using a multivariate clustering analysis algorithm developed by the authors (CYL). This type of analysis represents a relatively recent development in characterizing the structure of rock masses. It characterizes discontinuities into subsets according to multiple parameters, such as orientation, spacing, and roughness, where rather than considering one variable at a time, a number of parameters can be treated simultaneously, so that the interactions between parameters are taken into account. The comprehensive algorithm has been developed into a software package. It enables fully automated multivariate clustering analysis and offers various visualization tools, such as a three dimensional stereonet, a stereoscopic view, a statistical table, and pie charts relating the other factors such as lithology continuity, roughness, aperture, and infilling back to each cluster.

Meeting Name

40th U.S. Symposium on Rock Mechanics (USRMS): Rock Mechanics for Energy, Mineral and Infrastructure Development in the Northern Regions (2005: Jun. 25-29, Anchorage, AK)


Geosciences and Geological and Petroleum Engineering


National Science Foundation (U.S.)
University of Missouri Research Board

Keywords and Phrases

Clustering Analysis; Nuclear Waste Repository; Yucca Mountain, Nevada

Geographic Coverage


Document Type

Article - Conference proceedings

Document Version


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© 2005 American Rock Mechanics Association (ARMA), All rights reserved.

Publication Date

01 Sep 2005