Rheological Deformation of Surrounding Rock of Circular Tunnel Based on the Hoek-Brown Criterion
(1 State Key Laboratory for Geomechanics and Deep Underground Engineering, China University of Mining and Technology, Xuzhou 221008; 2 School of Civil Engineering and Architecture, Henan University, Kaifeng 475004)
Abstract：
In many cases, the nonlinear Hoek-Brown empirical criterion would be appropriate for engineering practice, however, there has been little research on analytical solutions for tunnel deformation by the nonlinear Hoek-Brown empirical criterion that considers the rheological behavior of the rock. Therefore, based on previous studies, the generalized Hoek-Brown criterion was used to research surrounding rock deformation under the rheological effect of an ideal elastic-brittle-plastic rock. First, in order to simplify the deduction process, an analytical solution for the rheological deformation of the surrouding rock was determined by the generalized Hoek-Brown criterion based on the assumption that the volume of the surrounding rock remains constant. Secondly, according to engineering practice, volume changes were taken into account while deducing the analytical solution for the rheological deformation of the surrouding rock by the nonassociated flow rule. Finally, the Bingham and visco-elastoplastic models were used, respectively, as the rheological models to calculate the two deductions, and it was concluded that the larger the dilatancy angle, the higher the h values as well as the rheological deformation of the surronding rock. Provided volume changes are not considered, and the calculated rheological deformation is smaller than that in practical cases.
2016, Vol. 53 