Abstract:

A large number of cracks have made the deformation properties of rock mass become very complex. However, the effect of these microcracks is often neglected in the research of rock mass deformation properties using numerical simulation method. In order to make clear the effect of theses microcracks on the deformation parameters of rock mass, the deformation parameters of  rock mass that contains one single microcrack are estimated based on equivalent deformation principle. Results show that the deformation characteristics of rock mass are related with the dip angle, the length and also the load orientation of the microcrack. When the length of the microcrack is longer, the deformation module of the rock mass is smaller and the Poisson ratio is bigger. When the intersection angle between the microcrack dip angle and the load orientation is smaller, the anisotropy of rock mass is more evident. Whereas with the increase of this intersection angle, the deformation moduli in different orientations are decreased, the Poisson ratios are increased and the anisotropy of the rock mass is weakened. When the intersection angle between the microcrack dip angle and the load orientation is 45°, the rock mass will be isotropic. 

Key words:  rock mechanics, microcrack, flexibility matrix, deformation parameters