In the IUCM, a linear Mohr-Coulomb criterion is used for the residual state of the rock mass. There is limited information available on the residual properties of rock masses.
In the IUCM, zero residual cohesion, tensile values, and a friction angle between 35° and 55° are recommended. These recommended values are based on the following:
• Work carried out by Barton and Kjærnsli (1981) and Aghaei Araei et al. (2010)
• Recommendations provided by Lorig and Varona (2013), Cai et al. (2007) and others; and
• Several numerical back-analysis studies were completed during the development of the IUCM (e.g. Vakili et al. 2012).
In all studies to validate the IUCM, zero cohesion, zero tension and a friction angle of 45° were used. Therefore, these values are currently assigned in the IUCM as default values.
References:
