Laboratory Estimation of Rock Joint Stiffness and Frictional Parameters


Numerical modeling of complex rock engineering problems involves the use of various input parameters which control usefulness of the output results. Hence, it is of utmost importance to select the right range of input physical and mechanical parameters based on laboratory or field estimation, and engineering judgment. Joint normal and shear stiffnesses are two popular input parameters to describe discontinuities in rock, which do not have specific guidelines for their estimation in literature. This study attempts to provide simple methods to estimate joint normal and shear stiffnesses in the laboratory using the uniaxial compression and small-scale direct shear tests. Samples have been prepared using rocks procured from different depths, geographical locations and formations. The study uses a mixture of relatively smooth natural joints and saw-cut joints in the various rock samples tested. The results indicate acceptable levels of uncertainty in the calculation of the stiffness parameters and provide a database of good first estimates and empirical relations which can be used for calculating values for joint stiffnesses when laboratory estimation is not possible. Joint basic friction angles have also been estimated as by-products in the small scale direct shear tests.


Mining Engineering


The work was funded by the NIOSH of the Centers for Disease Control and Prevention (Contract No. 200-2011-39886).

Keywords and Phrases

Joint basic friction angle; Joint normal stiffness; Joint shear stiffness; Normal stress

International Standard Serial Number (ISSN)

0960-3182; 1573-1529

Document Type

Article - Journal

Document Version


File Type





© 2016 Springer International Publishing, All rights reserved.

Publication Date

01 Dec 2016