Estimating the deformation modulus of jointed rock mass under multilateral loading condition using analytical methods

Determination of rock mass deformation modulus is very important in different projects, especially in civil and mining engineering works. in-situ measurements such as dilatometer, plate load and flat jack methods may be applied to determine the deformation modulus. however, these methods are very expensive and time- consuming. analytical methods are very useful approaches which can also be used to estimate rock mass deformation modulus. using these methods, the parameters influencing the rock mass modulus can also be evaluated. analytical methods are based on the resultant displacement of rock mass and joints which are finally used to predict the rock modulus. it should be mentioned that none of the available analytical models could present a model to consider the effect of lateral stresses on rock mass modulus calculations. therefore, this paper tries to investigate the effect of intermediate principal stress (?2) and minimum principal stress (?3) on the deformation modulus of jointed rock mass.