The linear stability of triply diffusive convection in a binary Maxwell fluid saturated porous layer is investigated. Applying normal mode analysis , the criterion for the onset of stationary and oscillatory convection is obtained. The modified Darcy-Maxwell model is used as the analysis model. This allows us to make a thorough investigation of the processes of viscoelasticity and diffusions that causes the convection to set in through oscillatory rather than stationary. The effects of the parameters of Vadasz number, normalized porosity parameter, relaxation parameter, Lewis number and solute Rayleigh number are presented.

The rheological long-term strength is determined according to the triaxial rheological test data of diabase at the dam area of Dagangshan Hydropower Station. Firstly, based on the stress-strain isochronous curve method and connected the test points with cubic spline interpolation function, the maximum deviation point in the long-term interval is determined as the turning point and established the long-term strength by nonlinear least square method. The results show that this method is consistent with the other methods. Finally, the advantage and disadvantage of this method is analyzed. This method can overcome the randomness of artificial selecting the turning points. Therefore, maximum deviation point method is relatively a reasonable and effective method to determine the rheological long-term strength of rock.

Seepage is one of the major influence factors for engineering stability. In this study, the equations of hydro-mechanical coupling in dual-porosity media including the governing equations of deformation and seepage are employed. The fluid gravity in whole system is considered in the seepage governing equation. The solid displacement, pore fluid pressure and fissure fluid pressure are the unknown qualities. The finite element formulation of the governing equations are acquired after using the Galerkin discretization technique. The physical parameters are discussed here. Finally, the state equation method is applied to solve the finite element equations.