ABSTRACT
The rock mass deformation modulus is an important input parameter in any analysis of rock structures and structures in or on rock. Although field tests are better methods to determine this parameter, but they are so time consuming and imply notable costs and operational difficulties. Therefore, their usage is limited to especial large projects. Using of empirical equations is common in other projects and also in initial study phase.A great part of empirical equations to rock mass deformation modulus estimation is based on rock mass classification systems such as RMR, Q, GSI and RMi.
